1
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Zhang MG, Seyedolmohadesin M, Mercado SH, Tauffenberger A, Park H, Finnen N, Schroeder FC, Venkatachalam V, Sternberg PW. Sensory integration of food and population density during the diapause exit decision involves insulin-like signaling in Caenorhabditis elegans. Proc Natl Acad Sci U S A 2024; 121:e2405391121. [PMID: 39316052 PMCID: PMC11459166 DOI: 10.1073/pnas.2405391121] [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: 03/19/2024] [Accepted: 08/20/2024] [Indexed: 09/25/2024] Open
Abstract
Decisions made over long time scales, such as life cycle decisions, require coordinated interplay between sensory perception and sustained gene expression. The Caenorhabditis elegans dauer (or diapause) exit developmental decision requires sensory integration of population density and food availability to induce an all-or-nothing organismal-wide response, but the mechanism by which this occurs remains unknown. Here, we demonstrate how the Amphid Single Cilium J (ASJ) chemosensory neurons, known to be critical for dauer exit, perform sensory integration at both the levels of gene expression and calcium activity. In response to favorable conditions, dauers rapidly produce and secrete the dauer exit-promoting insulin-like peptide INS-6. Expression of ins-6 in the ASJ neurons integrates population density and food level and can reflect decision commitment since dauers committed to exiting have higher ins-6 expression levels than those of noncommitted dauers. Calcium imaging in dauers reveals that the ASJ neurons are activated by food, and this activity is suppressed by pheromone, indicating that sensory integration also occurs at the level of calcium transients. We find that ins-6 expression in the ASJ neurons depends on neuronal activity in the ASJs, cGMP signaling, and the pheromone components ascr#8 and ascr#2. We propose a model in which decision commitment to exit the dauer state involves an autoregulatory feedback loop in the ASJ neurons that promotes high INS-6 production and secretion. These results collectively demonstrate how insulin-like peptide signaling helps animals compute long-term decisions by bridging sensory perception to decision execution.
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Affiliation(s)
- Mark G. Zhang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | | | - Soraya Hawk Mercado
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Arnaud Tauffenberger
- Boyce Thompson Institute, Cornell University, Ithaca, NY14853
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY14853
| | - Heenam Park
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Nerissa Finnen
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Frank C. Schroeder
- Boyce Thompson Institute, Cornell University, Ithaca, NY14853
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY14853
| | | | - Paul W. Sternberg
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
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2
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Wang YH, Lin CW, Huang CW. Polyunsaturated Fatty Acids as Potential Treatments for COVID-19-Induced Anosmia. Biomedicines 2024; 12:2085. [PMID: 39335598 PMCID: PMC11428228 DOI: 10.3390/biomedicines12092085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2024] [Revised: 09/05/2024] [Accepted: 09/09/2024] [Indexed: 09/30/2024] Open
Abstract
Some individuals with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) experience anosmia, or loss of smell. Although the prevalence of anosmia has decreased with the emergence of the Omicron variant, it remains a significant concern. This review examines the potential role of polyunsaturated fatty acids (PUFAs), particularly omega-3 PUFAs, in treating COVID-19-induced anosmia by focusing on the underlying mechanisms of the condition. Omega-3 PUFAs are known for their anti-inflammatory, neuroprotective, and neurotransmission-enhancing properties, which could potentially aid in olfactory recovery. However, study findings are inconsistent. For instance, a placebo-controlled randomized clinical trial found no significant effect of omega-3 PUFA supplementation on olfactory recovery in patients with COVID-19-induced anosmia. These mixed results highlight the limitations of existing research, including small sample sizes, lack of placebo controls, short follow-up periods, and combined treatments. Therefore, more rigorous, large-scale studies are urgently needed to definitively assess the therapeutic potential of omega-3 PUFAs for olfactory dysfunction. Further research is also crucial to explore the broader role of PUFAs in managing viral infections and promoting sensory recovery.
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Affiliation(s)
- Yu-Han Wang
- Department of Education, National Taiwan University Hospital, Taipei 100, Taiwan
| | - Chung-Wei Lin
- Department of Education, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan
- Department of Otolaryngology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan
| | - Chiung-Wei Huang
- Department of Physiology, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Department of Post-Baccalaureate Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
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3
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Zhang Y, Iino Y, Schafer WR. Behavioral plasticity. Genetics 2024; 228:iyae105. [PMID: 39158469 DOI: 10.1093/genetics/iyae105] [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: 02/01/2024] [Accepted: 06/10/2024] [Indexed: 08/20/2024] Open
Abstract
Behavioral plasticity allows animals to modulate their behavior based on experience and environmental conditions. Caenorhabditis elegans exhibits experience-dependent changes in its behavioral responses to various modalities of sensory cues, including odorants, salts, temperature, and mechanical stimulations. Most of these forms of behavioral plasticity, such as adaptation, habituation, associative learning, and imprinting, are shared with other animals. The C. elegans nervous system is considerably tractable for experimental studies-its function can be characterized and manipulated with molecular genetic methods, its activity can be visualized and analyzed with imaging approaches, and the connectivity of its relatively small number of neurons are well described. Therefore, C. elegans provides an opportunity to study molecular, neuronal, and circuit mechanisms underlying behavioral plasticity that are either conserved in other animals or unique to this species. These findings reveal insights into how the nervous system interacts with the environmental cues to generate behavioral changes with adaptive values.
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Affiliation(s)
- Yun Zhang
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
- Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - Yuichi Iino
- Department of Biological Sciences, University of Tokyo, Tokyo 113-0032, Japan
| | - William R Schafer
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, Cambridgeshire CB2 0QH, UK
- Department of Biology, KU Leuven, 3000 Leuven, Belgium
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4
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Hill TJ, Sengupta P. Feedforward and feedback mechanisms cooperatively regulate rapid experience-dependent response adaptation in a single thermosensory neuron type. Proc Natl Acad Sci U S A 2024; 121:e2321430121. [PMID: 38530893 PMCID: PMC10998601 DOI: 10.1073/pnas.2321430121] [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: 12/05/2023] [Accepted: 02/27/2024] [Indexed: 03/28/2024] Open
Abstract
Sensory adaptation allows neurons to adjust their sensitivity and responses based on recent experience. The mechanisms that mediate continuous adaptation to stimulus history over seconds- to hours-long timescales, and whether these mechanisms can operate within a single sensory neuron type, are unclear. The single pair of AFD thermosensory neurons in Caenorhabditis elegans exhibits experience-dependent plasticity in their temperature response thresholds on both minutes- and hours-long timescales upon a temperature upshift. While long-term response adaptation requires changes in gene expression in AFD, the mechanisms driving rapid response plasticity are unknown. Here, we show that rapid thermosensory response adaptation in AFD is mediated via cGMP and calcium-dependent feedforward and feedback mechanisms operating at the level of primary thermotransduction. We find that either of two thermosensor receptor guanylyl cyclases (rGCs) alone is sufficient to drive rapid adaptation, but that each rGC drives adaptation at different rates. rGC-driven adaptation is mediated in part via phosphorylation of their intracellular domains, and calcium-dependent feedback regulation of basal cGMP levels via a neuronal calcium sensor protein. In turn, cGMP levels feedforward via cGMP-dependent protein kinases to phosphorylate a specific subunit of the cGMP-gated thermotransduction channel to further regulate rapid adaptation. Our results identify multiple molecular pathways that act in AFD to ensure rapid adaptation to a temperature change and indicate that the deployment of both transcriptional and nontranscriptional mechanisms within a single sensory neuron type can contribute to continuous sensory adaptation.
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Affiliation(s)
- Tyler J. Hill
- Department of Biology, Brandeis University, Waltham, MA02454
| | - Piali Sengupta
- Department of Biology, Brandeis University, Waltham, MA02454
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5
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Zhang MG, Seyedolmohadesin M, Hawk S, Park H, Finnen N, Schroeder F, Venkatachalam V, Sternberg PW. Sensory integration of food availability and population density during the diapause exit decision involves insulin-like signaling in Caenorhabditis elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.20.586022. [PMID: 38586049 PMCID: PMC10996498 DOI: 10.1101/2024.03.20.586022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Decisions made over long time scales, such as life cycle decisions, require coordinated interplay between sensory perception and sustained gene expression. The Caenorhabditis elegans dauer (or diapause) exit developmental decision requires sensory integration of population density and food availability to induce an all-or-nothing organismal-wide response, but the mechanism by which this occurs remains unknown. Here, we demonstrate how the ASJ chemosensory neurons, known to be critical for dauer exit, perform sensory integration at both the levels of gene expression and calcium activity. In response to favorable conditions, dauers rapidly produce and secrete the dauer exit-promoting insulin-like peptide INS-6. Expression of ins-6 in the ASJ neurons integrate population density and food level and can reflect decision commitment since dauers committed to exiting have higher ins-6 expression levels than those of non-committed dauers. Calcium imaging in dauers reveals that the ASJ neurons are activated by food, and this activity is suppressed by pheromone, indicating that sensory integration also occurs at the level of calcium transients. We find that ins-6 expression in the ASJ neurons depends on neuronal activity in the ASJs, cGMP signaling, a CaM-kinase pathway, and the pheromone components ascr#8 and ascr#2. We propose a model in which decision commitment to exit the dauer state involves an autoregulatory feedback loop in the ASJ neurons that promotes high INS-6 production and secretion. These results collectively demonstrate how insulin-like peptide signaling helps animals compute long-term decisions by bridging sensory perception to decision execution.
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Affiliation(s)
- Mark G Zhang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | | | - Soraya Hawk
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Heenam Park
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Nerissa Finnen
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Frank Schroeder
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | | | - Paul W Sternberg
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
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6
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Suryawinata N, Yokosawa R, Tan KHC, Lai AL, Sone R, Mori I, Noma K. Dietary E. coli promotes age-dependent chemotaxis decline in C. elegans. Sci Rep 2024; 14:5529. [PMID: 38448519 PMCID: PMC10918063 DOI: 10.1038/s41598-024-52272-4] [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: 10/05/2023] [Accepted: 01/16/2024] [Indexed: 03/08/2024] Open
Abstract
An animal's ability to sense odors declines during aging, and its olfactory drive is tuned by internal states such as satiety. However, whether internal states modulate an age-dependent decline in odor sensation is unknown. To address this issue, we utilized the nematode Caenorhabditis elegans and compared their chemotaxis abilities toward attractive odorants when aged under different dietary conditions. Feeding with the standard laboratory diet, Escherichia coli attenuated the chemotaxis ability toward diacetyl, isoamyl alcohol, and benzaldehyde when aged. On the other hand, feeding with either the lactic acid bacteria Lactobacillus reuteri or food deprivation selectively maintained the chemotaxis ability toward diacetyl. Our results suggest that ingestion of E. coli causes age-dependent chemotaxis decline. The changes in the chemotaxis behavior are attributed to the different expressions of diacetyl receptor odr-10, and the chemotaxis behavior of aged animals under food deprivation is shown to be dependent on daf-16. Our study demonstrates the molecular mechanism of how diet shapes the trajectory of age-dependent decline in chemosensory behaviors.
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Affiliation(s)
- Nadia Suryawinata
- Group of Nutritional Neuroscience, Graduate School of Science, Neuroscience Institute, Nagoya University, Nagoya, 464-8602, Japan
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E California Blvd, Pasadena, CA, 91125, USA
| | - Rikuou Yokosawa
- Group of Nutritional Neuroscience, Graduate School of Science, Neuroscience Institute, Nagoya University, Nagoya, 464-8602, Japan
- Group of Microbial Motility, Division of Natural Science, Department of Biological Science, Graduate School of Science, Nagoya University, Nagoya, 464-8602, Japan
| | - Ke Hui Cassandra Tan
- Group of Nutritional Neuroscience, Graduate School of Science, Neuroscience Institute, Nagoya University, Nagoya, 464-8602, Japan
| | - Alison Lok Lai
- Group of Nutritional Neuroscience, Graduate School of Science, Neuroscience Institute, Nagoya University, Nagoya, 464-8602, Japan
| | - Ryusei Sone
- Group of Nutritional Neuroscience, Graduate School of Science, Neuroscience Institute, Nagoya University, Nagoya, 464-8602, Japan
- Group of Microbial Motility, Division of Natural Science, Department of Biological Science, Graduate School of Science, Nagoya University, Nagoya, 464-8602, Japan
| | - Ikue Mori
- Group of Molecular Neurobiology, Graduate School of Science, Neuroscience Institute, Nagoya University, Nagoya, 464-8602, Japan
| | - Kentaro Noma
- Group of Nutritional Neuroscience, Graduate School of Science, Neuroscience Institute, Nagoya University, Nagoya, 464-8602, Japan.
- Group of Microbial Motility, Division of Natural Science, Department of Biological Science, Graduate School of Science, Nagoya University, Nagoya, 464-8602, Japan.
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7
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Hill TJ, Sengupta P. Feedforward and feedback mechanisms cooperatively regulate rapid experience-dependent response adaptation in a single thermosensory neuron type. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.05.570166. [PMID: 38168209 PMCID: PMC10760192 DOI: 10.1101/2023.12.05.570166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Sensory adaptation allows neurons to adjust their sensitivity and responses based on recent experience. The mechanisms that mediate continuous adaptation to stimulus history over seconds to hours long timescales, and whether these mechanisms can operate within a single sensory neuron type, are unclear. The single pair of AFD thermosensory neurons in C. elegans exhibits experience-dependent plasticity in their temperature response thresholds on both minutes- and hours-long timescales upon a temperature upshift. While long-term response adaptation requires changes in gene expression in AFD, the mechanisms driving rapid response plasticity are unknown. Here, we show that rapid thermosensory response adaptation in AFD is mediated via cGMP and calcium-dependent feedforward and feedback mechanisms operating at the level of primary thermotransduction. We find that either of two thermosensor receptor guanylyl cyclases (rGCs) alone is sufficient to drive rapid adaptation, but that each rGC drives adaptation at different rates. rGC-driven adaptation is mediated in part via phosphorylation of their intracellular domains, and calcium-dependent feedback regulation of basal cGMP levels via a neuronal calcium sensor protein. In turn, cGMP levels feedforward via cGMP-dependent protein kinases to phosphorylate a specific subunit of the cGMP-gated thermotransduction channel to further regulate rapid adaptation. Our results identify multiple molecular pathways that act in AFD to ensure rapid adaptation to a temperature change, and indicate that the deployment of both transcriptional and non-transcriptional mechanisms within a single sensory neuron type can contribute to continuous sensory adaptation.
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Affiliation(s)
- Tyler J. Hill
- Department of Biology, Brandeis University, Waltham, MA 02454
| | - Piali Sengupta
- Department of Biology, Brandeis University, Waltham, MA 02454
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8
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Chandra R, Farah F, Muñoz-Lobato F, Bokka A, Benedetti KL, Brueggemann C, Saifuddin MFA, Miller JM, Li J, Chang E, Varshney A, Jimenez V, Baradwaj A, Nassif C, Alladin S, Andersen K, Garcia AJ, Bi V, Nordquist SK, Dunn RL, Garcia V, Tokalenko K, Soohoo E, Briseno F, Kaur S, Harris M, Guillen H, Byrd D, Fung B, Bykov AE, Odisho E, Tsujimoto B, Tran A, Duong A, Daigle KC, Paisner R, Zuazo CE, Lin C, Asundi A, Churgin MA, Fang-Yen C, Bremer M, Kato S, VanHoven MK, L'Étoile ND. Sleep is required to consolidate odor memory and remodel olfactory synapses. Cell 2023; 186:2911-2928.e20. [PMID: 37269832 PMCID: PMC10354834 DOI: 10.1016/j.cell.2023.05.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 02/02/2023] [Accepted: 05/05/2023] [Indexed: 06/05/2023]
Abstract
Animals with complex nervous systems demand sleep for memory consolidation and synaptic remodeling. Here, we show that, although the Caenorhabditis elegans nervous system has a limited number of neurons, sleep is necessary for both processes. In addition, it is unclear if, in any system, sleep collaborates with experience to alter synapses between specific neurons and whether this ultimately affects behavior. C. elegans neurons have defined connections and well-described contributions to behavior. We show that spaced odor-training and post-training sleep induce long-term memory. Memory consolidation, but not acquisition, requires a pair of interneurons, the AIYs, which play a role in odor-seeking behavior. In worms that consolidate memory, both sleep and odor conditioning are required to diminish inhibitory synaptic connections between the AWC chemosensory neurons and the AIYs. Thus, we demonstrate in a living organism that sleep is required for events immediately after training that drive memory consolidation and alter synaptic structures.
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Affiliation(s)
- Rashmi Chandra
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Fatima Farah
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Fernando Muñoz-Lobato
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Anirudh Bokka
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Kelli L Benedetti
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Chantal Brueggemann
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Mashel Fatema A Saifuddin
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Julia M Miller
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Joy Li
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Eric Chang
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Aruna Varshney
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Vanessa Jimenez
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Anjana Baradwaj
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Cibelle Nassif
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Sara Alladin
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Kristine Andersen
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Angel J Garcia
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Veronica Bi
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Sarah K Nordquist
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Raymond L Dunn
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Vanessa Garcia
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Kateryna Tokalenko
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Emily Soohoo
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Fabiola Briseno
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Sukhdeep Kaur
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Malcolm Harris
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Hazel Guillen
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Decklin Byrd
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Brandon Fung
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Andrew E Bykov
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Emma Odisho
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Bryan Tsujimoto
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Alan Tran
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Alex Duong
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Kevin C Daigle
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Rebekka Paisner
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Carlos E Zuazo
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Christine Lin
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Aarati Asundi
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Matthew A Churgin
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Christopher Fang-Yen
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Martina Bremer
- Department of Mathematics and Statistics, San José State University, San José, CA 95192, USA
| | - Saul Kato
- Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Miri K VanHoven
- Department of Biological Sciences, San José State University, San José, CA 95192, USA.
| | - Noëlle D L'Étoile
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA.
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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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Ikejiri Y, Tanimoto Y, Fujita K, Hiramatsu F, Yamazaki SJ, Endo Y, Iwatani Y, Fujimoto K, Kimura KD. Neural mechanism of experience-dependent sensory gain control in C. elegans. Neurosci Res 2023; 191:77-90. [PMID: 36681153 DOI: 10.1016/j.neures.2023.01.006] [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: 11/03/2022] [Revised: 01/15/2023] [Accepted: 01/16/2023] [Indexed: 01/20/2023]
Abstract
Animals' sensory systems adjust their responsiveness to environmental stimuli that vary greatly in their intensity. Here we report the neural mechanism of experience-dependent sensory adjustment, especially gain control, in the ASH nociceptive neurons in Caenorhabditis elegans. Using calcium imaging under gradual changes in stimulus intensity, we find that the ASH neurons of naive animals respond to concentration increases in a repulsive odor 2-nonanone regardless of the magnitude of the concentration increase. However, after preexposure to the odor, the ASH neurons exhibit significantly weak responses to a small gradual increase in odor concentration while their responses to a large gradual increase remain strong. Thus, preexposure changes the slope of stimulus-response relationships (i.e., gain control). Behavioral analysis suggests that this gain control contributes to the preexposure-dependent enhancement of odor avoidance behavior. Mathematical analysis reveals that the ASH response consists of fast and slow components, and that the fast component is specifically suppressed by preexposure for the gain control. In addition, genetic analysis suggests that G protein signaling may be required for the regulation of fast component. We propose how prior experience dynamically and specifically modulates stimulus-response relationships in sensory neurons, eventually leading to adaptive modulation of behavior.
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Affiliation(s)
- Yosuke Ikejiri
- Department of Information and Basic Science, Graduate School of Science, Nagoya City University, Nagoya, Aichi 467-8501, Japan; Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Yuki Tanimoto
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Kosuke Fujita
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Fumie Hiramatsu
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Shuhei J Yamazaki
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Yuto Endo
- Department of Information and Basic Science, Graduate School of Science, Nagoya City University, Nagoya, Aichi 467-8501, Japan; Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Yasushi Iwatani
- Department of Science and Technology, Graduate School of Science and Technology, Hirosaki University, Hirosaki, Aomori 036-8561, Japan
| | - Koichi Fujimoto
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Koutarou D Kimura
- Department of Information and Basic Science, Graduate School of Science, Nagoya City University, Nagoya, Aichi 467-8501, Japan; Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
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11
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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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12
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Lindsay JH, Mathies LD, Davies AG, Bettinger JC. A neuropeptide signal confers ethanol state dependency during olfactory learning in Caenorhabditis elegans. Proc Natl Acad Sci U S A 2022; 119:e2210462119. [PMID: 36343256 PMCID: PMC9674237 DOI: 10.1073/pnas.2210462119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 09/15/2022] [Indexed: 11/09/2022] Open
Abstract
Alcohol intoxication can impact learning and this may contribute to the development of problematic alcohol use. In alcohol (ethanol)-induced state-dependent learning (SDL), information learned while an animal is intoxicated is recalled more effectively when the subject is tested while similarly intoxicated than if tested while not intoxicated. When Caenorhabditis elegans undergoes olfactory learning (OL) while intoxicated, the learning becomes state dependent such that recall of OL is only apparent if the animals are tested while intoxicated. We found that two genes known to be required for signal integration, the secreted peptide HEN-1 and its receptor tyrosine kinase, SCD-2, are required for SDL. Expression of hen-1 in the ASER neuron and scd-2 in the AIA neurons was sufficient for their functions in SDL. Optogenetic activation of ASER in the absence of ethanol during learning could confer ethanol state dependency, indicating that ASER activation is sufficient to signal ethanol intoxication to the OL circuit. To our surprise, ASER activation during testing did not substitute for ethanol intoxication, demonstrating that the effects of ethanol on learning and recall rely on distinct signals. Additionally, intoxication-state information could be added to already established OL, but state-dependent OL did not lose state information when the intoxication signal was removed. Finally, dopamine is required for state-dependent OL, and we found that the activation of ASER cannot bypass this requirement. Our findings provide a window into the modulation of learning by ethanol and suggest that ethanol acts to modify learning using mechanisms distinct from those used during memory access.
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Affiliation(s)
- Jonathan H. Lindsay
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA 23298
| | - Laura D. Mathies
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA 23298
- VCU-Alcohol Research Center, Virginia Commonwealth University, Richmond, VA 23298
| | - Andrew G. Davies
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA 23298
- VCU-Alcohol Research Center, Virginia Commonwealth University, Richmond, VA 23298
| | - Jill C. Bettinger
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA 23298
- VCU-Alcohol Research Center, Virginia Commonwealth University, Richmond, VA 23298
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13
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Pribadi AK, Chalasani SH. Fear conditioning in invertebrates. Front Behav Neurosci 2022; 16:1008818. [PMID: 36439964 PMCID: PMC9686301 DOI: 10.3389/fnbeh.2022.1008818] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 10/19/2022] [Indexed: 09/30/2023] Open
Abstract
Learning to identify and predict threats is a basic skill that allows animals to avoid harm. Studies in invertebrates like Aplysia californica, Drosophila melanogaster, and Caenorhabditis elegans have revealed that the basic mechanisms of learning and memory are conserved. We will summarize these studies and highlight the common pathways and mechanisms in invertebrate fear-associated behavioral changes. Fear conditioning studies utilizing electric shock in Aplysia and Drosophila have demonstrated that serotonin or dopamine are typically involved in relaying aversive stimuli, leading to changes in intracellular calcium levels and increased presynaptic neurotransmitter release and short-term changes in behavior. Long-term changes in behavior typically require multiple, spaced trials, and involve changes in gene expression. C. elegans studies have demonstrated these basic aversive learning principles as well; however, fear conditioning has yet to be explicitly demonstrated in this model due to stimulus choice. Because predator-prey relationships can be used to study learned fear in a naturalistic context, this review also summarizes what is known about predator-induced behaviors in these three organisms, and their potential applications for future investigations into fear conditioning.
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Affiliation(s)
- Amy K. Pribadi
- Biological Sciences Graduate Program, University of California, San Diego, La Jolla, San Diego, CA, United States
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, United States
| | - Sreekanth H. Chalasani
- Biological Sciences Graduate Program, University of California, San Diego, La Jolla, San Diego, CA, United States
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, United States
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14
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Cheng D, Lee JS, Brown M, Ebert MS, McGrath PT, Tomioka M, Iino Y, Bargmann CI. Insulin/IGF signaling regulates presynaptic glutamate release in aversive olfactory learning. Cell Rep 2022; 41:111685. [DOI: 10.1016/j.celrep.2022.111685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 08/06/2022] [Accepted: 10/27/2022] [Indexed: 11/23/2022] Open
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15
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Positive interaction between ASH and ASK sensory neurons accelerates nociception and inhibits behavioral adaptation. iScience 2022; 25:105287. [PMID: 36304123 PMCID: PMC9593764 DOI: 10.1016/j.isci.2022.105287] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 05/22/2022] [Accepted: 10/04/2022] [Indexed: 11/23/2022] Open
Abstract
Central and peripheral sensory neurons tightly regulate nociception and avoidance behavior. The peripheral modulation of nociception provides more veridical and instantaneous information for animals to achieve rapid, more fine-tuned and concentrated behavioral responses. In this study, we find that positive interaction between ASH and ASK sensory neurons is essential for the fast-rising phase of ASH Ca2+ responses to noxious copper ions and inhibits the adaption of avoiding Cu2+. We reveal the underlying neuronal circuit mechanism. ASK accelerates the ASH Ca2+ responses by transferring cGMP through gap junctions. ASH excites ASK via a disinhibitory neuronal circuit composed of ASH, AIA, and ASK. Avoidance adaptation depends on the slope rate of the rising phase of ASH Ca2+ responses. Thus, in addition to amplitude, sensory kinetics is significant for sensations and behaviors, especially for sensory and behavioral adaptations.
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16
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Bhat VD, Jayaraj J, Babu K. RNA and neuronal function: the importance of post-transcriptional regulation. OXFORD OPEN NEUROSCIENCE 2022; 1:kvac011. [PMID: 38596700 PMCID: PMC10913846 DOI: 10.1093/oons/kvac011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 05/03/2022] [Accepted: 05/28/2022] [Indexed: 04/11/2024]
Abstract
The brain represents an organ with a particularly high diversity of genes that undergo post-transcriptional gene regulation through multiple mechanisms that affect RNA metabolism and, consequently, brain function. This vast regulatory process in the brain allows for a tight spatiotemporal control over protein expression, a necessary factor due to the unique morphologies of neurons. The numerous mechanisms of post-transcriptional regulation or translational control of gene expression in the brain include alternative splicing, RNA editing, mRNA stability and transport. A large number of trans-elements such as RNA-binding proteins and micro RNAs bind to specific cis-elements on transcripts to dictate the fate of mRNAs including its stability, localization, activation and degradation. Several trans-elements are exemplary regulators of translation, employing multiple cofactors and regulatory machinery so as to influence mRNA fate. Networks of regulatory trans-elements exert control over key neuronal processes such as neurogenesis, synaptic transmission and plasticity. Perturbations in these networks may directly or indirectly cause neuropsychiatric and neurodegenerative disorders. We will be reviewing multiple mechanisms of gene regulation by trans-elements occurring specifically in neurons.
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Affiliation(s)
- Vandita D Bhat
- Centre for Neuroscience, Indian Institute of Science, CV Raman Road, Bangalore 560012, Karnataka, India
| | - Jagannath Jayaraj
- Centre for Neuroscience, Indian Institute of Science, CV Raman Road, Bangalore 560012, Karnataka, India
| | - Kavita Babu
- Centre for Neuroscience, Indian Institute of Science, CV Raman Road, Bangalore 560012, Karnataka, India
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17
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Chen J, Zhou Y, Lei Y, Shi Q, Qi G, He Y, Lyu L. Role of the foraging gene in worker behavioral transition in the red imported fire ant, Solenopsis invicta (Hymenoptera: Formicidae). PEST MANAGEMENT SCIENCE 2022; 78:2964-2975. [PMID: 35419943 DOI: 10.1002/ps.6921] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 03/11/2022] [Accepted: 04/14/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Worker division of labor is predominant in social insects. The foraging (for) gene, which encodes cGMP-dependent protein kinase (PKG), has been implicated in the regulation of behavioral transitions in honeybees, but information regarding its function in other social insects is scarce. RESULTS We investigated the role of the for (Sifor) gene in the red imported fire ant, Solenopsis invicta, and found that Sifor and PKG exhibited different expression patterns in different castes, body sizes, ages and tissues of fire ants, especially in foragers and nurses. Foragers displayed greater locomotor activity but showed no preference for larval or adult odors, whereas nurses showed lesser locomotor activity but had a strong preference for larval odors. We found that the expression of Sifor was significantly higher in the heads of foragers (compared to nurses). RNA interference-mediated Sifor knockdown in foraging workers induced behavioral transition of foragers toward the nurse phenotype characterized by reduced locomotor activity and a stronger preference for larval odors. By contrast, treating nurses with 8-Br-cGMP, an activator of PKG, resulted in behavioral transition toward the forager phenotype characterized by higher locomotor activity but reduced preference for larval odors. CONCLUSION Our results suggest that Sifor plays a critical role in the behavioral transition between foragers and nurses of workers, which may be a promising target for RNAi-based management of worker caste organization in S. invicta. © 2022 Society of Chemical Industry.
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Affiliation(s)
- Jie Chen
- Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Yangyang Zhou
- Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China
- Department of Entomology, College of Plant Protection, South China Agricultural University, Guangzhou, China
| | - Yanyuan Lei
- Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Qingxing Shi
- Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Guojun Qi
- Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Yurong He
- Department of Entomology, College of Plant Protection, South China Agricultural University, Guangzhou, China
| | - Lihua Lyu
- Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China
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18
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Khan M, Hartmann AH, O’Donnell MP, Piccione M, Pandey A, Chao PH, Dwyer ND, Bargmann CI, Sengupta P. Context-dependent reversal of odorant preference is driven by inversion of the response in a single sensory neuron type. PLoS Biol 2022; 20:e3001677. [PMID: 35696430 PMCID: PMC9232122 DOI: 10.1371/journal.pbio.3001677] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 06/24/2022] [Accepted: 05/16/2022] [Indexed: 11/18/2022] Open
Abstract
The valence and salience of individual odorants are modulated by an animal’s innate preferences, learned associations, and internal state, as well as by the context of odorant presentation. The mechanisms underlying context-dependent flexibility in odor valence are not fully understood. Here, we show that the behavioral response of Caenorhabditis elegans to bacterially produced medium-chain alcohols switches from attraction to avoidance when presented in the background of a subset of additional attractive chemicals. This context-dependent reversal of odorant preference is driven by cell-autonomous inversion of the response to these alcohols in the single AWC olfactory neuron pair. We find that while medium-chain alcohols inhibit the AWC olfactory neurons to drive attraction, these alcohols instead activate AWC to promote avoidance when presented in the background of a second AWC-sensed odorant. We show that these opposing responses are driven via engagement of distinct odorant-directed signal transduction pathways within AWC. Our results indicate that context-dependent recruitment of alternative intracellular signaling pathways within a single sensory neuron type conveys opposite hedonic valences, thereby providing a robust mechanism for odorant encoding and discrimination at the periphery.
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Affiliation(s)
- Munzareen Khan
- Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
| | - Anna H. Hartmann
- Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
| | - Michael P. O’Donnell
- Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
| | - Madeline Piccione
- Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
| | - Anjali Pandey
- Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
| | - Pin-Hao Chao
- Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
| | - Noelle D. Dwyer
- Department of Cell Biology, University of Virginia, Charlottesville, Virginia, United States of America
| | | | - Piali Sengupta
- Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
- * E-mail:
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19
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The foraging Gene Is Involved in the Presence of Wings and Explorative Behaviours in Parthenogenetic Females of the Aphid Myzus persicae. Life (Basel) 2022; 12:life12030369. [PMID: 35330120 PMCID: PMC8951518 DOI: 10.3390/life12030369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 02/24/2022] [Accepted: 03/02/2022] [Indexed: 11/17/2022] Open
Abstract
The foraging gene (for) encodes for a cyclic guanosine monophosphate (cGMP)-dependent protein kinase involved in behavioural plasticity in aphids and in other insects. In this paper, we analysed the complete for sequence in eight clones of the peach potato aphid Myzus persicae, reporting the presence of nonsense and frameshift mutations in three studied clones characterized by a reduced number of winged females and by the absence of exploratory behaviours. Quantitative PCR experiments evidenced similar results in clones possessing for genes with a conserved coding sequence, but low expression levels. The comparison of the for transcriptional level in Myzus persicae persicae and Myzus persicae nicotianae showed very different expression in the two studied M. p. nicotianae clones so that our data did not support a previous hypothesis suggesting that a differential for expression was related to ecological specialization of M. p. nicotianae. In view of its role in both the dispersal of winged females and exploratory behaviours, the screening of the for sequences could be useful for predicting invasions of cultivated areas by peach potato aphids.
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20
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Zhang B, Lam KY, Ni WM, Signorelli R, Collins KM, Fu Z, Zhai L, Lou Y, DeAngelis DL, Hastings A. Directed movement changes coexistence outcomes in heterogeneous environments. Ecol Lett 2022; 25:366-377. [PMID: 34818698 PMCID: PMC8799502 DOI: 10.1111/ele.13925] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 10/11/2021] [Accepted: 10/27/2021] [Indexed: 02/03/2023]
Abstract
Understanding mechanisms of coexistence is a central topic in ecology. Mathematical analysis of models of competition between two identical species moving at different rates of symmetric diffusion in heterogeneous environments show that the slower mover excludes the faster one. The models have not been tested empirically and lack inclusions of a component of directed movement toward favourable areas. To address these gaps, we extended previous theory by explicitly including exploitable resource dynamics and directed movement. We tested the mathematical results experimentally using laboratory populations of the nematode worm, Caenorhabditis elegans. Our results not only support the previous theory that the species diffusing at a slower rate prevails in heterogeneous environments but also reveal that moderate levels of a directed movement component on top of the diffusive movement allow species to coexist. Our results broaden the theory of species coexistence in heterogeneous space and provide empirical confirmation of the mathematical predictions.
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Affiliation(s)
- Bo Zhang
- Department of Integrative Biology, Oklahoma State University, United States
| | - King-Yeung Lam
- Department of Mathematics, Ohio State University, United States
| | - Wei-Ming Ni
- Chinese University of Hong Kong – Shenzhen, China
| | | | | | - Zhiyuan Fu
- Co-Innovation Center for Sustainable Forestry in Southern China, Jiangsu Province Key Laboratory of Soil and Water Conservation and Ecological Restoration, Nanjing Forestry University, China
| | - Lu Zhai
- Department of Natural Ecology Resource and Management, Oklahoma State University, United States
| | - Yuan Lou
- Department of Mathematics, Ohio State University, United States
| | | | - Alan Hastings
- Department of Environmental Science and Policy, University of California, Davis, United States; Santa Fe Institute, United States
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21
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Tsukahara T, Brann DH, Pashkovski SL, Guitchounts G, Bozza T, Datta SR. A transcriptional rheostat couples past activity to future sensory responses. Cell 2021; 184:6326-6343.e32. [PMID: 34879231 PMCID: PMC8758202 DOI: 10.1016/j.cell.2021.11.022] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 10/07/2021] [Accepted: 11/11/2021] [Indexed: 10/19/2022]
Abstract
Animals traversing different environments encounter both stable background stimuli and novel cues, which are thought to be detected by primary sensory neurons and then distinguished by downstream brain circuits. Here, we show that each of the ∼1,000 olfactory sensory neuron (OSN) subtypes in the mouse harbors a distinct transcriptome whose content is precisely determined by interactions between its odorant receptor and the environment. This transcriptional variation is systematically organized to support sensory adaptation: expression levels of more than 70 genes relevant to transforming odors into spikes continuously vary across OSN subtypes, dynamically adjust to new environments over hours, and accurately predict acute OSN-specific odor responses. The sensory periphery therefore separates salient signals from predictable background via a transcriptional rheostat whose moment-to-moment state reflects the past and constrains the future; these findings suggest a general model in which structured transcriptional variation within a cell type reflects individual experience.
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Affiliation(s)
- Tatsuya Tsukahara
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - David H Brann
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Stan L Pashkovski
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | | | - Thomas Bozza
- Department of Neurobiology, Northwestern University, Evanston, IL 60208, USA
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Hsu TY, Hsu LN, Chen SY, Juang BT. MUT-7 Provides Molecular Insight into the Werner Syndrome Exonuclease. Cells 2021; 10:cells10123457. [PMID: 34943966 PMCID: PMC8700014 DOI: 10.3390/cells10123457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/01/2021] [Accepted: 12/05/2021] [Indexed: 11/24/2022] Open
Abstract
Werner syndrome (WS) is a rare recessive genetic disease characterized by premature aging. Individuals with this disorder develop normally during childhood, but their physiological conditions exacerbate the aging process in late adolescence. WS is caused by mutation of the human WS gene (WRN), which encodes two main domains, a 3′-5′ exonuclease and a 3′-5′ helicase. Caenorhabditis elegans expresses human WRN orthologs as two different proteins: MUT-7, which has a 3′-5′ exonuclease domain, and C. elegans WRN-1 (CeWRN-1), which has only helicase domains. These unique proteins dynamically regulate olfactory memory in C. elegans, providing insight into the molecular roles of WRN domains in humans. In this review, we specifically focus on characterizing the function of MUT-7 in small interfering RNA (siRNA) synthesis in the cytoplasm and the roles of siRNA in directing nuclear CeWRN-1 loading onto a heterochromatin complex to induce negative feedback regulation. Further studies on the different contributions of the 3′-5′ exonuclease and helicase domains in the molecular mechanism will provide clues to the accelerated aging processes in WS.
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Affiliation(s)
- Tsung-Yuan Hsu
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan;
- Department of Cell and Tissue Biology, University of California, 513 Parnassus, San Francisco, CA 94143, USA
| | - Ling-Nung Hsu
- Occupational Safety and Health Office, Fu Jen Catholic University Hospital, New Taipei City 243, Taiwan;
| | - Shih-Yu Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan;
| | - Bi-Tzen Juang
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan;
- Center for Intelligent Drug Systems and Smart Bio-Devices (IDS2B), National Chiao Tung University, Hsinchu 300, Taiwan
- Correspondence:
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23
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Rahmani A, Chew YL. Investigating the molecular mechanisms of learning and memory using Caenorhabditis elegans. J Neurochem 2021; 159:417-451. [PMID: 34528252 DOI: 10.1111/jnc.15510] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 08/15/2021] [Accepted: 09/08/2021] [Indexed: 11/30/2022]
Abstract
Learning is an essential biological process for survival since it facilitates behavioural plasticity in response to environmental changes. This process is mediated by a wide variety of genes, mostly expressed in the nervous system. Many studies have extensively explored the molecular and cellular mechanisms underlying learning and memory. This review will focus on the advances gained through the study of the nematode Caenorhabditis elegans. C. elegans provides an excellent system to study learning because of its genetic tractability, in addition to its invariant, compact nervous system (~300 neurons) that is well-characterised at the structural level. Importantly, despite its compact nature, the nematode nervous system possesses a high level of conservation with mammalian systems. These features allow the study of genes within specific sensory-, inter- and motor neurons, facilitating the interrogation of signalling pathways that mediate learning via defined neural circuits. This review will detail how learning and memory can be studied in C. elegans through behavioural paradigms that target distinct sensory modalities. We will also summarise recent studies describing mechanisms through which key molecular and cellular pathways are proposed to affect associative and non-associative forms of learning.
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Affiliation(s)
- Aelon Rahmani
- Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia
| | - Yee Lian Chew
- Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia
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Ow MC, Hall SE. piRNAs and endo-siRNAs: Small molecules with large roles in the nervous system. Neurochem Int 2021; 148:105086. [PMID: 34082061 PMCID: PMC8286337 DOI: 10.1016/j.neuint.2021.105086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 04/23/2021] [Accepted: 05/26/2021] [Indexed: 01/02/2023]
Abstract
Since their discovery, small non-coding RNAs have emerged as powerhouses in the regulation of numerous cellular processes. In addition to guarding the integrity of the reproductive system, small non-coding RNAs play critical roles in the maintenance of the soma. Accumulating evidence indicates that small non-coding RNAs perform vital functions in the animal nervous system such as restricting the activity of deleterious transposable elements, regulating nerve regeneration, and mediating learning and memory. In this review, we provide an overview of the current understanding of the contribution of two major classes of small non-coding RNAs, piRNAs and endo-siRNAs, to the nervous system development and function, and present highlights on how the dysregulation of small non-coding RNA pathways can assist in understanding the neuropathology of human neurological disorders.
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Affiliation(s)
- Maria C Ow
- Biology Department, Syracuse University, 107 College Place, Syracuse, NY, 13244, USA.
| | - Sarah E Hall
- Biology Department, Syracuse University, 107 College Place, Syracuse, NY, 13244, USA.
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25
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Lucas C, Ben-Shahar Y. The foraging gene as a modulator of division of labour in social insects. J Neurogenet 2021; 35:168-178. [PMID: 34151702 DOI: 10.1080/01677063.2021.1940173] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The social ants, bees, wasps, and termites include some of the most ecologically-successful groups of animal species. Their dominance in most terrestrial environments is attributed to their social lifestyle, which enable their colonies to exploit environmental resources with remarkable efficiency. One key attribute of social insect colonies is the division of labour that emerges among the sterile workers, which represent the majority of colony members. Studies of the mechanisms that drive division of labour systems across diverse social species have provided fundamental insights into the developmental, physiological, molecular, and genomic processes that regulate sociality, and the possible genetic routes that may have led to its evolution from a solitary ancestor. Here we specifically discuss the conserved role of the foraging gene, which encodes a cGMP-dependent protein kinase (PKG). Originally identified as a behaviourally polymorphic gene that drives alternative foraging strategies in the fruit fly Drosophila melanogaster, changes in foraging expression and kinase activity were later shown to play a key role in the division of labour in diverse social insect species as well. In particular, foraging appears to regulate worker transitions between behavioural tasks and specific behavioural traits associated with morphological castes. Although the specific neuroethological role of foraging in the insect brain remains mostly unknown, studies in genetically tractable insect species indicate that PKG signalling plays a conserved role in the neuronal plasticity of sensory, cognitive and motor functions, which underlie behaviours relevant to division of labour, including appetitive learning, aggression, stress response, phototaxis, and the response to pheromones.
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Affiliation(s)
- Christophe Lucas
- Institut de Recherche sur la Biologie de l'Insecte (UMR7261), CNRS - University of Tours, Tours, France
| | - Yehuda Ben-Shahar
- Department of Biology, Washington University in St. Louis, St. Louis, MO, USA
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26
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Ravi B, Zhao J, Chaudhry I, Signorelli R, Bartole M, Kopchock RJ, Guijarro C, Kaplan JM, Kang L, Collins KM. Presynaptic Gαo (GOA-1) signals to depress command neuron excitability and allow stretch-dependent modulation of egg laying in Caenorhabditis elegans. Genetics 2021; 218:6284136. [PMID: 34037773 DOI: 10.1093/genetics/iyab080] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 05/18/2021] [Indexed: 12/29/2022] Open
Abstract
Egg laying in the nematode worm Caenorhabditis elegans is a two-state behavior modulated by internal and external sensory input. We have previously shown that homeostatic feedback of embryo accumulation in the uterus regulates bursting activity of the serotonergic HSN command neurons that sustains the egg-laying active state. How sensory feedback of egg release signals to terminate the egg-laying active state is less understood. We find that Gαo, a conserved Pertussis Toxin-sensitive G protein, signals within HSN to inhibit egg-laying circuit activity and prevent entry into the active state. Gαo signaling hyperpolarizes HSN, reducing HSN Ca2+ activity and input onto the postsynaptic vulval muscles. Loss of inhibitory Gαo signaling uncouples presynaptic HSN activity from a postsynaptic, stretch-dependent homeostat, causing precocious entry into the egg-laying active state when only a few eggs are present in the uterus. Feedback of vulval opening and egg release activates the uv1 neuroendocrine cells which release NLP-7 neuropeptides which signal to inhibit egg laying through Gαo-independent mechanisms in the HSNs and Gαo-dependent mechanisms in cells other than the HSNs. Thus, neuropeptide and inhibitory Gαo signaling maintains a bi-stable state of electrical excitability that dynamically controls circuit activity in response to both external and internal sensory input to drive a two-state behavior output.
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Affiliation(s)
- Bhavya Ravi
- Neuroscience Program, University of Miami Miller School of Medicine, Miami, FL USA 33136.,Department of Biology, University of Miami, Coral Gables, FL USA 33146
| | - Jian Zhao
- Department of Neuroscience, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Department of Molecular Biology, Massachusetts General Hospital, Boston, MA USA 02114
| | - I Chaudhry
- Department of Biology, University of Miami, Coral Gables, FL USA 33146
| | | | - Mattingly Bartole
- Neuroscience Program, University of Miami Miller School of Medicine, Miami, FL USA 33136.,Department of Biology, University of Miami, Coral Gables, FL USA 33146
| | | | | | - Joshua M Kaplan
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA USA 02114
| | - Lijun Kang
- Department of Neuroscience, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Kevin M Collins
- Neuroscience Program, University of Miami Miller School of Medicine, Miami, FL USA 33136.,Department of Biology, University of Miami, Coral Gables, FL USA 33146
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27
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Hino T, Hirai S, Ishihara T, Fujiwara M. EGL-4/PKG regulates the role of an interneuron in a chemotaxis circuit of C. elegans through mediating integration of sensory signals. Genes Cells 2021; 26:411-425. [PMID: 33817914 DOI: 10.1111/gtc.12849] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/31/2021] [Accepted: 03/31/2021] [Indexed: 11/30/2022]
Abstract
Interneurons, innervated by multiple sensory neurons, need to integrate information from these sensory neurons and respond to sensory stimuli adequately. Mechanisms how sensory information is integrated to form responses of interneurons are not fully understood. In Caenorhabditis elegans, loss-of-function mutations of egl-4, which encodes a cGMP-dependent protein kinase (PKG), cause a defect in chemotaxis to odorants. Our genetic and imaging analyses revealed that the response property of AIY interneuron to an odorant is reversed in the egl-4 mutant, while the responses of two upstream olfactory neurons, AWA and AWC, are largely unchanged. Cell- ablation experiments show that AIY in the egl-4 mutant functions to suppress chemotaxis. Furthermore, the reversal of AIY response occurs only in the presence of sensory signals from both AWA and AWC. These results suggest that sensory signals are inadequately integrated in the egl-4 mutant. We also show that egl-4 expression in AWA and another sensory neuron prevents the reversed AIY response and restores chemotaxis in the egl-4 mutants. We propose that EGL-4/PKG, by suppressing aberrant integration of signals from olfactory neurons, converts the response property of an interneuron to olfactory stimuli and maintains the role of the interneuron in the circuit to execute chemotactic behavior.
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Affiliation(s)
- Takahiro Hino
- Department of Biology, Faculty of Science, Kyushu University, Fukuoka, Japan
| | - Shota Hirai
- Department of Biology, Faculty of Science, Kyushu University, Fukuoka, Japan
| | - Takeshi Ishihara
- Department of Biology, Faculty of Science, Kyushu University, Fukuoka, Japan
| | - Manabi Fujiwara
- Department of Biology, Faculty of Science, Kyushu University, Fukuoka, Japan
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28
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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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29
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Hsu TY, Zhang B, L'Etoile ND, Juang BT. C. elegans orthologs MUT-7/CeWRN-1 of Werner syndrome protein regulate neuronal plasticity. eLife 2021; 10:62449. [PMID: 33646120 PMCID: PMC7946423 DOI: 10.7554/elife.62449] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 02/26/2021] [Indexed: 12/28/2022] Open
Abstract
Caenorhabditis elegans expresses human Werner syndrome protein (WRN) orthologs as two distinct proteins: MUT-7, with a 3′−5′ exonuclease domain, and CeWRN-1, with helicase domains. How these domains cooperate remains unclear. Here, we demonstrate the different contributions of MUT-7 and CeWRN-1 to 22G small interfering RNA (siRNA) synthesis and the plasticity of neuronal signaling. MUT-7 acts specifically in the cytoplasm to promote siRNA biogenesis and in the nucleus to associate with CeWRN-1. The import of siRNA by the nuclear Argonaute NRDE-3 promotes the loading of the heterochromatin-binding protein HP1 homolog HPL-2 onto specific loci. This heterochromatin complex represses the gene expression of the guanylyl cyclase ODR-1 to direct olfactory plasticity in C. elegans. Our findings suggest that the exonuclease and helicase domains of human WRN may act in concert to promote RNA-dependent loading into a heterochromatin complex, and the failure of this entire process reduces plasticity in postmitotic neurons.
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Affiliation(s)
- Tsung-Yuan Hsu
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, United States
| | - Bo Zhang
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, United States
| | - Noelle D L'Etoile
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, United States
| | - Bi-Tzen Juang
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan
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30
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Abstract
Caenorhabditis elegans' behavioral states, like those of other animals, are shaped by its immediate environment, its past experiences, and by internal factors. We here review the literature on C. elegans behavioral states and their regulation. We discuss dwelling and roaming, local and global search, mate finding, sleep, and the interaction between internal metabolic states and behavior.
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Affiliation(s)
- Steven W Flavell
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - David M Raizen
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Young-Jai You
- Division of Biological Science, Graduate School of Science, Nagoya University, 464-8602, Japan
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31
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C. elegans episodic swimming is driven by multifractal kinetics. Sci Rep 2020; 10:14775. [PMID: 32901071 PMCID: PMC7478975 DOI: 10.1038/s41598-020-70319-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 07/27/2020] [Indexed: 12/21/2022] Open
Abstract
Fractal scaling is a common property of temporal change in various modes of animal behavior. The molecular mechanisms of fractal scaling in animal behaviors remain largely unexplored. The nematode C. elegans alternates between swimming and resting states in a liquid solution. Here, we report that C. elegans episodic swimming is characterized by scale-free kinetics with long-range temporal correlation and local temporal clusterization, namely consistent with multifractal kinetics. Residence times in actively-moving and inactive states were distributed in a power law-based scale-free manner. Multifractal analysis showed that temporal correlation and temporal clusterization were distinct between the actively-moving state and the inactive state. These results indicate that C. elegans episodic swimming is driven by transition between two behavioral states, in which each of two transition kinetics follows distinct multifractal kinetics. We found that a conserved behavioral modulator, cyclic GMP dependent kinase (PKG) may regulate the multifractal kinetics underlying an animal behavior. Our combinatorial analysis approach involving molecular genetics and kinetics provides a platform for the molecular dissection of the fractal nature of physiological and behavioral phenomena.
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32
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Park J, Meisel JD, Kim DH. Immediate activation of chemosensory neuron gene expression by bacterial metabolites is selectively induced by distinct cyclic GMP-dependent pathways in Caenorhabditis elegans. PLoS Genet 2020; 16:e1008505. [PMID: 32776934 PMCID: PMC7416920 DOI: 10.1371/journal.pgen.1008505] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 06/15/2020] [Indexed: 01/19/2023] Open
Abstract
Dynamic gene expression in neurons shapes fundamental processes in the nervous systems of animals. However, how neuronal activation by different stimuli can lead to distinct transcriptional responses is not well understood. We have been studying how microbial metabolites modulate gene expression in chemosensory neurons of Caenorhabditis elegans. Considering the diverse environmental stimuli that can activate chemosensory neurons of C. elegans, we sought to understand how specific transcriptional responses can be generated in these neurons in response to distinct cues. We have focused on the mechanism of rapid (<6 min) and selective transcriptional induction of daf-7, a gene encoding a TGF-β ligand, in the ASJ chemosensory neurons in response to the pathogenic bacterium Pseudomonas aeruginosa. DAF-7 is required for the protective behavioral avoidance of P. aeruginosa by C. elegans. Here, we define the involvement of two distinct cyclic GMP (cGMP)-dependent pathways that are required for daf-7 expression in the ASJ neuron pair in response to P. aeruginosa. We show that a calcium-independent pathway dependent on the cGMP-dependent protein kinase G (PKG) EGL-4, and a canonical calcium-dependent signaling pathway dependent on the activity of a cyclic nucleotide-gated channel subunit CNG-2, function in parallel to activate rapid, selective transcription of daf-7 in response to P. aeruginosa metabolites. Our data suggest that fast, selective early transcription of neuronal genes require PKG in shaping responses to distinct microbial stimuli in a pair of C. elegans chemosensory neurons.
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Affiliation(s)
- Jaeseok Park
- Division of Infectious Diseases, Boston Children’s Hospital, and Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Joshua D. Meisel
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Dennis H. Kim
- Division of Infectious Diseases, Boston Children’s Hospital, and Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, United States of America
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Abstract
Nervous systems allow animals to acutely respond and behaviorally adapt to changes and recurring patterns in their environment at multiple timescales-from milliseconds to years. Behavior is further shaped at intergenerational timescales by genetic variation, drift, and selection. This sophistication and flexibility of behavior makes it challenging to measure behavior consistently in individual subjects and to compare it across individuals. In spite of these challenges, careful behavioral observations in nature and controlled measurements in the laboratory, combined with modern technologies and powerful genetic approaches, have led to important discoveries about the way genetic variation shapes behavior. A critical mass of genes whose variation is known to modulate behavior in nature is finally accumulating, allowing us to recognize emerging patterns. In this review, we first discuss genetic mapping approaches useful for studying behavior. We then survey how variation acts at different levels-in environmental sensation, in internal neuronal circuits, and outside the nervous system altogether-and then discuss the sources and types of molecular variation linked to behavior and the mechanisms that shape such variation. We end by discussing remaining questions in the field.
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Affiliation(s)
- Natalie Niepoth
- Zuckerman Mind Brain Behavior Institute and Department of Ecology, Evolution, and Environmental Biology, Columbia University, New York, NY 10027, USA; ,
| | - Andres Bendesky
- Zuckerman Mind Brain Behavior Institute and Department of Ecology, Evolution, and Environmental Biology, Columbia University, New York, NY 10027, USA; ,
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34
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Levy S, Bargmann CI. An Adaptive-Threshold Mechanism for Odor Sensation and Animal Navigation. Neuron 2019; 105:534-548.e13. [PMID: 31761709 DOI: 10.1016/j.neuron.2019.10.034] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 05/31/2019] [Accepted: 10/27/2019] [Indexed: 01/01/2023]
Abstract
Identifying the environmental information and computations that drive sensory detection is key for understanding animal behavior. Using experimental and theoretical analysis of AWCON, a well-described olfactory neuron in C. elegans, here we derive a general and broadly useful model that matches stimulus history to odor sensation and behavioral responses. We show that AWCON sensory activity is regulated by an absolute signal threshold that continuously adapts to odor history, allowing animals to compare present and past odor concentrations. The model predicts sensory activity and probabilistic behavior during animal navigation in different odor gradients and across a broad stimulus regime. Genetic studies demonstrate that the cGMP-dependent protein kinase EGL-4 determines the timescale of threshold adaptation, defining a molecular basis for a critical model feature. The adaptive threshold model efficiently filters stimulus noise, allowing reliable sensation in fluctuating environments, and represents a feedforward sensory mechanism with implications for other sensory systems.
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Affiliation(s)
- Sagi Levy
- Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
| | - Cornelia I Bargmann
- Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA; Chan Zuckerberg Initiative, Palo Alto, CA 94301, USA
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35
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Activity-Dependent Regulation of the Proapoptotic BH3-Only Gene egl-1 in a Living Neuron Pair in Caenorhabditis elegans. G3-GENES GENOMES GENETICS 2019; 9:3703-3714. [PMID: 31519744 PMCID: PMC6829140 DOI: 10.1534/g3.119.400654] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The BH3-only family of proteins is key for initiating apoptosis in a variety of contexts, and may also contribute to non-apoptotic cellular processes. Historically, the nematode Caenorhabditis elegans has provided a powerful system for studying and identifying conserved regulators of BH3-only proteins. In C. elegans, the BH3-only protein egl-1 is expressed during development to cell-autonomously trigger most developmental cell deaths. Here we provide evidence that egl-1 is also transcribed after development in the sensory neuron pair URX without inducing apoptosis. We used genetic screening and epistasis analysis to determine that its transcription is regulated in URX by neuronal activity and/or in parallel by orthologs of Protein Kinase G and the Salt-Inducible Kinase family. Because several BH3-only family proteins are also expressed in the adult nervous system of mammals, we suggest that studying egl-1 expression in URX may shed light on mechanisms that regulate conserved family members in higher organisms.
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Abstract
The Drosophila melanogaster foraging (for) gene is a well-established example of a gene with major effects on behavior and natural variation. This gene is best known for underlying the behavioral strategies of rover and sitter foraging larvae, having been mapped and named for this phenotype. Nevertheless, in the last three decades an extensive array of studies describing for's role as a modifier of behavior in a wide range of phenotypes, in both Drosophila and other organisms, has emerged. Furthermore, recent work reveals new insights into the genetic and molecular underpinnings of how for affects these phenotypes. In this article, we discuss the history of the for gene and its role in natural variation in behavior, plasticity, and behavioral pleiotropy, with special attention to recent findings on the molecular structure and transcriptional regulation of this gene.
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Affiliation(s)
- Ina Anreiter
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario M5S 3B2, Canada;
| | - Marla B Sokolowski
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario M5S 3B2, Canada;
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37
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Posner R, Toker IA, Antonova O, Star E, Anava S, Azmon E, Hendricks M, Bracha S, Gingold H, Rechavi O. Neuronal Small RNAs Control Behavior Transgenerationally. Cell 2019; 177:1814-1826.e15. [PMID: 31178120 PMCID: PMC6579485 DOI: 10.1016/j.cell.2019.04.029] [Citation(s) in RCA: 101] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 02/18/2019] [Accepted: 04/13/2019] [Indexed: 12/21/2022]
Abstract
It is unknown whether the activity of the nervous system can be inherited. In Caenorhabditis elegans nematodes, parental responses can transmit heritable small RNAs that regulate gene expression transgenerationally. In this study, we show that a neuronal process can impact the next generations. Neurons-specific synthesis of RDE-4-dependent small RNAs regulates germline amplified endogenous small interfering RNAs (siRNAs) and germline gene expression for multiple generations. Further, the production of small RNAs in neurons controls the chemotaxis behavior of the progeny for at least three generations via the germline Argonaute HRDE-1. Among the targets of these small RNAs, we identified the conserved gene saeg-2, which is transgenerationally downregulated in the germline. Silencing of saeg-2 following neuronal small RNA biogenesis is required for chemotaxis under stress. Thus, we propose a small-RNA-based mechanism for communication of neuronal processes transgenerationally. C. elegans neuronal small RNAs are characterized by RNA sequencing RDE-4-dependent neuronal endogenous small RNAs communicate with the germline Germline HRDE-1 mediates transgenerational regulation by neuronal small RNAs Neuronal small RNAs regulate germline genes to control behavior transgenerationally
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Affiliation(s)
- Rachel Posner
- Department of Neurobiology, Wise Faculty of Life Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Itai Antoine Toker
- Department of Neurobiology, Wise Faculty of Life Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Olga Antonova
- Department of Neurobiology, Wise Faculty of Life Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Ekaterina Star
- Department of Neurobiology, Wise Faculty of Life Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Sarit Anava
- Department of Neurobiology, Wise Faculty of Life Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Eran Azmon
- Department of Neurobiology, Wise Faculty of Life Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Michael Hendricks
- Department of Biology, McGill University, Montreal, QC H3A 1B1, Canada
| | - Shahar Bracha
- Department of Neurobiology, Wise Faculty of Life Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Hila Gingold
- Department of Neurobiology, Wise Faculty of Life Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Oded Rechavi
- Department of Neurobiology, Wise Faculty of Life Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel.
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38
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Peymen K, Watteyne J, Borghgraef C, Van Sinay E, Beets I, Schoofs L. Myoinhibitory peptide signaling modulates aversive gustatory learning in Caenorhabditis elegans. PLoS Genet 2019; 15:e1007945. [PMID: 30779740 PMCID: PMC6380545 DOI: 10.1371/journal.pgen.1007945] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Accepted: 01/07/2019] [Indexed: 11/18/2022] Open
Abstract
Aversive learning and memories are crucial for animals to avoid previously encountered stressful stimuli and thereby increase their chance of survival. Neuropeptides are essential signaling molecules in the brain and are emerging as important modulators of learned behaviors, but their precise role is not well understood. Here, we show that neuropeptides of the evolutionarily conserved MyoInhibitory Peptide (MIP)-family modify salt chemotaxis behavior in Caenorhabditis elegans according to previous experience. MIP signaling, through activation of the G protein-coupled receptor SPRR-2, is required for short-term gustatory plasticity. In addition, MIP/SPRR-2 neuropeptide-receptor signaling mediates another type of aversive gustatory learning called salt avoidance learning that depends on de novo transcription, translation and the CREB transcription factor, all hallmarks of long-term memory. MIP/SPRR-2 signaling mediates salt avoidance learning in parallel with insulin signaling. These findings lay a foundation to investigate the suggested orphan MIP receptor orthologs in deuterostomians, including human GPR139 and GPR142. All animals rely on learning and memory processes to learn from experience and thereby increase their chance of survival. Neuropeptides are essential signaling molecules in the brain and are emerging as important modulators of learning and memory processes. We found that the C. elegans receptor SPRR-2 and its ligands, the MIP-1 neuropeptides—which are members of the evolutionarily conserved myoinhibitory peptide system—are required for aversive gustatory learning. Our results provide a basis for investigations into the poorly characterized MIP systems in deuterostomians, including humans, and suggest a possible function in learning for human MIP signaling.
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Affiliation(s)
- Katleen Peymen
- Department of Biology, University of Leuven (KU Leuven), Leuven, Belgium
| | - Jan Watteyne
- Department of Biology, University of Leuven (KU Leuven), Leuven, Belgium
| | | | - Elien Van Sinay
- Department of Biology, University of Leuven (KU Leuven), Leuven, Belgium
| | - Isabel Beets
- Department of Biology, University of Leuven (KU Leuven), Leuven, Belgium
- * E-mail: (IB); (LS)
| | - Liliane Schoofs
- Department of Biology, University of Leuven (KU Leuven), Leuven, Belgium
- * E-mail: (IB); (LS)
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Donato A, Kagias K, Zhang Y, Hilliard MA. Neuronal sub-compartmentalization: a strategy to optimize neuronal function. Biol Rev Camb Philos Soc 2019; 94:1023-1037. [PMID: 30609235 PMCID: PMC6617802 DOI: 10.1111/brv.12487] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 11/21/2018] [Accepted: 11/23/2018] [Indexed: 12/14/2022]
Abstract
Neurons are highly polarized cells that consist of three main structural and functional domains: a cell body or soma, an axon, and dendrites. These domains contain smaller compartments with essential roles for proper neuronal function, such as the axonal presynaptic boutons and the dendritic postsynaptic spines. The structure and function of these compartments have now been characterized in great detail. Intriguingly, however, in the last decade additional levels of compartmentalization within the axon and the dendrites have been identified, revealing that these structures are much more complex than previously thought. Herein we examine several types of structural and functional sub-compartmentalization found in neurons of both vertebrates and invertebrates. For example, in mammalian neurons the axonal initial segment functions as a sub-compartment to initiate the action potential, to select molecules passing into the axon, and to maintain neuronal polarization. Moreover, work in Drosophila melanogaster has shown that two distinct axonal guidance receptors are precisely clustered in adjacent segments of the commissural axons both in vivo and in vitro, suggesting a cell-intrinsic mechanism underlying the compartmentalized receptor localization. In Caenorhabditis elegans, a subset of interneurons exhibits calcium dynamics that are localized to specific sections of the axon and control the gait of navigation, demonstrating a regulatory role of compartmentalized neuronal activity in behaviour. These findings have led to a number of new questions, which are important for our understanding of neuronal development and function. How are these sub-compartments established and maintained? What molecular machinery and cellular events are involved? What is their functional significance for the neuron? Here, we reflect on these and other key questions that remain to be addressed in this expanding field of biology.
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Affiliation(s)
- Alessandra Donato
- Clem Jones Centre for Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia
| | - Konstantinos Kagias
- Department of Organismic and Evolutionary Biology, Center for Brain Science, Harvard University, Cambridge, MA 02138, U.S.A
| | - Yun Zhang
- Department of Organismic and Evolutionary Biology, Center for Brain Science, Harvard University, Cambridge, MA 02138, U.S.A
| | - Massimo A Hilliard
- Clem Jones Centre for Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia
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Gastropod parasitic nematodes ( Phasmarhabditis sp.) are attracted to hyaluronic acid in snail mucus by cGMP signalling. J Helminthol 2018; 94:e9. [PMID: 30428945 DOI: 10.1017/s0022149x18000986] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Phasmarhabditis hermaphrodita is a parasitic nematode of terrestrial gastropods that has been formulated into a biological control agent for farmers and gardeners to kill slugs and snails. In order to locate slugs it is attracted to mucus, faeces and volatile cues; however, there is no information about whether these nematodes are attracted to snail cues. It is also unknown how wild isolates of P. hermaphrodita or different Phasmarhabditis species behave when exposed to gastropod cues. Therefore, we investigated whether P. hermaphrodita (commercial and wild isolated strains), P. neopapillosa and P. californica were attracted to mucus from several common snail species (Cepaea nemoralis, Cepaea hortensis, Arianta arbustorum and Cornu aspersum). We also examined whether snails (C. aspersum) collected from different locations around the UK differed in their attractiveness to wild isolates of P. hermaphrodita. Furthermore, we also investigated what properties of snail mucus the nematodes were attracted to, including hyaluronic acid and metal salts (FeSO4, ZnSO4, CuSO4 and MgSO4). We found that the commercial strain of P. hermaphrodita responded poorly to snail mucus compared to wild isolated strains, and C. aspersum collected from different parts of the UK differed in their attractiveness to the nematodes. We found that Phasmarhabditis nematodes were weakly attracted to all metals tested but were strongly attracted to hyaluronic acid. In a final experiment we also showed that pharmacological manipulation of cyclic guanosine monophosphate (cGMP) increased chemoattraction to snail mucus, suggesting that the protein kinase EGL-4 may be responsible for Phasmarhabditis sp. chemoattraction.
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Choi JI, Lee HK, Kim HS, Park SY, Lee TY, Yoon KH, Lee JI. Odor-dependent temporal dynamics in Caenorhabitis elegans adaptation and aversive learning behavior. PeerJ 2018; 6:e4956. [PMID: 29910981 PMCID: PMC6003392 DOI: 10.7717/peerj.4956] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 05/22/2018] [Indexed: 01/19/2023] Open
Abstract
Animals sense an enormous number of cues in their environments, and, over time, can form learned associations and memories with some of these. The nervous system remarkably maintains the specificity of learning and memory to each of the cues. Here we asked whether the nematode Caenorhabditis elegans adjusts the temporal dynamics of adaptation and aversive learning depending on the specific odor sensed. C. elegans senses a multitude of odors, and adaptation and learned associations to many of these odors requires activity of the cGMP-dependent protein kinase EGL-4 in the AWC sensory neuron. We identified a panel of 17 attractive odors, some of which have not been tested before, and determined that the majority of these odors require the AWC primary sensory neuron for sensation. We then devised a novel assay to assess odor behavior over time for a single population of animals. We used this assay to evaluate the temporal dynamics of adaptation and aversive learning to 13 odors and find that behavior change occurs early in some odors and later in others. We then examined EGL-4 localization in early-trending and late-trending odors over time. We found that the timing of these behavior changes correlated with the timing of nuclear accumulation of EGL-4 in the AWC neuron suggesting that temporal changes in behavior may be mediated by aversive learning mechanisms. We demonstrate that temporal dynamics of adaptation and aversive learning in C. elegans can be used as a model to study the timing of memory formation to different sensory cues.
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Affiliation(s)
- Jae Im Choi
- Division of Biological Science and Technology, Yonsei University, Wonju, Gangwondo, South Korea
| | - Hee Kyung Lee
- Division of Biological Science and Technology, Yonsei University, Wonju, Gangwondo, South Korea.,Mitohormesis Research Center, Department of Physiology, Wonju College of Medicine, Yonsei University, Wonju, Gangwondo, South Korea
| | - Hae Su Kim
- Division of Biological Science and Technology, Yonsei University, Wonju, Gangwondo, South Korea
| | - So Young Park
- Division of Biological Science and Technology, Yonsei University, Wonju, Gangwondo, South Korea
| | - Tong Young Lee
- Division of Biological Science and Technology, Yonsei University, Wonju, Gangwondo, South Korea
| | - Kyoung-Hye Yoon
- Division of Biological Science and Technology, Yonsei University, Wonju, Gangwondo, South Korea.,Mitohormesis Research Center, Department of Physiology, Wonju College of Medicine, Yonsei University, Wonju, Gangwondo, South Korea
| | - Jin I Lee
- Division of Biological Science and Technology, Yonsei University, Wonju, Gangwondo, South Korea
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Risley MG, Kelly SP, Minnerly J, Jia K, Dawson-Scully K. egl-4 modulates electroconvulsive seizure duration in C. elegans. INVERTEBRATE NEUROSCIENCE 2018; 18:8. [PMID: 29845318 DOI: 10.1007/s10158-018-0211-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 04/30/2018] [Indexed: 12/16/2022]
Abstract
Increased neuronal excitability causes seizures with debilitating symptoms. Effective and noninvasive treatments are limited for easing symptoms, partially due to the complexity of the disorder and lack of knowledge of specific molecular faults. An unexplored, novel target for seizure therapeutics is the cGMP/protein kinase G (PKG) pathway, which targets downstream K+ channels, a mechanism similar to Retigabine, a recently FDA-approved antiepileptic drug. Our results demonstrate that increased PKG activity decreased seizure duration in C. elegans utilizing a recently developed electroconvulsive seizure assay. While the fly is a well-established seizure model, C. elegans are an ideal yet unexploited model which easily uptakes drugs and can be utilized for high-throughput screens. In this study, we show that treating the worms with either a potassium channel opener, Retigabine or published pharmaceuticals that increase PKG activity, significantly reduces seizure recovery times. Our results suggest that PKG signaling modulates downstream K+ channel conductance to control seizure recovery time in C. elegans. Hence, we provide powerful evidence, suggesting that pharmacological manipulation of the PKG signaling cascade may control seizure duration across phyla.
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Affiliation(s)
- Monica G Risley
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, FL, 33431, USA.,International Max-Planck Research School (IMPRS) for Brain and Behavior, Boca Raton, FL, 33431, USA
| | - Stephanie P Kelly
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, FL, 33431, USA.,International Max-Planck Research School (IMPRS) for Brain and Behavior, Boca Raton, FL, 33431, USA
| | - Justin Minnerly
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, FL, 33431, USA.,International Max-Planck Research School (IMPRS) for Brain and Behavior, Boca Raton, FL, 33431, USA
| | - Kailiang Jia
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, FL, 33431, USA.,International Max-Planck Research School (IMPRS) for Brain and Behavior, Boca Raton, FL, 33431, USA
| | - Ken Dawson-Scully
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, FL, 33431, USA. .,International Max-Planck Research School (IMPRS) for Brain and Behavior, Boca Raton, FL, 33431, USA.
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Muthaiyan Shanmugam M, Bhan P, Huang HY, Hsieh J, Hua TE, Wu GH, Punjabi H, Lee Aplícano VD, Chen CW, Wagner OI. Cilium Length and Intraflagellar Transport Regulation by Kinases PKG-1 and GCK-2 in Caenorhabditis elegans Sensory Neurons. Mol Cell Biol 2018; 38:e00612-17. [PMID: 29378827 PMCID: PMC5854826 DOI: 10.1128/mcb.00612-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2017] [Revised: 12/21/2017] [Accepted: 01/18/2018] [Indexed: 12/31/2022] Open
Abstract
To understand how ciliopathies such as polycystic kidney disease or Bardet-Biedl syndrome develop, we need to understand the basic molecular mechanisms underlying cilium development. Cilium growth depends on the presence of functional intraflagellar transport (IFT) machinery, and we hypothesized that various kinases and phosphatases might be involved in this regulatory process. A candidate screen revealed two kinases, PKG-1 (a cGMP-dependent protein kinase) and GCK-2 (a mitogen-activated protein kinase kinase kinase kinase 3 [MAP4K3] kinase involved in mTOR signaling), significantly affecting dye filling, chemotaxis, cilium morphology, and IFT component distribution. PKG-1 and GCK-2 show similar expression patterns in Caenorhabditis elegans cilia and colocalize with investigated IFT machinery components. In pkg-1 mutants, a high level of accumulation of kinesin-2 OSM-3 in distal segments was observed in conjunction with an overall reduction of anterograde and retrograde IFT particle A transport, likely as a function of reduced tubulin acetylation. In contrast, in gck-2 mutants, both kinesin-2 motility and IFT particle A motility were significantly elevated in the middle segments, in conjunction with increased tubulin acetylation, possibly the cause of longer cilium growth. Observed effects in mutants can be also seen in manipulating upstream and downstream effectors of the respective cGMP and mTOR pathways. Importantly, transmission electron microscopy (TEM) analysis revealed no structural changes in cilia of pkg-1 and gck-2 mutants.
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Affiliation(s)
- Muniesh Muthaiyan Shanmugam
- National Tsing Hua University, Institute of Molecular and Cellular Biology, Department of Life Science, Hsinchu, Taiwan, Republic of China
| | - Prerana Bhan
- National Tsing Hua University, Institute of Molecular and Cellular Biology, Department of Life Science, Hsinchu, Taiwan, Republic of China
| | - Hsin-Yi Huang
- National Tsing Hua University, Institute of Molecular and Cellular Biology, Department of Life Science, Hsinchu, Taiwan, Republic of China
| | - Jung Hsieh
- National Tsing Hua University, Institute of Molecular and Cellular Biology, Department of Life Science, Hsinchu, Taiwan, Republic of China
| | - Tzu-En Hua
- Electron Microscopy Core Facility, Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, Republic of China
| | - Gong-Her Wu
- National Tsing Hua University, Institute of Molecular and Cellular Biology, Department of Life Science, Hsinchu, Taiwan, Republic of China
| | - Helly Punjabi
- National Tsing Hua University, Institute of Molecular and Cellular Biology, Department of Life Science, Hsinchu, Taiwan, Republic of China
| | - Víctor Daniel Lee Aplícano
- National Tsing Hua University, Institute of Molecular and Cellular Biology, Department of Life Science, Hsinchu, Taiwan, Republic of China
| | - Chih-Wei Chen
- National Tsing Hua University, Institute of Molecular and Cellular Biology, Department of Life Science, Hsinchu, Taiwan, Republic of China
| | - Oliver Ingvar Wagner
- National Tsing Hua University, Institute of Molecular and Cellular Biology, Department of Life Science, Hsinchu, Taiwan, Republic of China
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The extraordinary AFD thermosensor of C. elegans. Pflugers Arch 2017; 470:839-849. [PMID: 29218454 DOI: 10.1007/s00424-017-2089-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 11/17/2017] [Indexed: 12/19/2022]
Abstract
The nematode C. elegans exhibits complex thermal experience-dependent navigation behaviors in response to environmental temperature changes of as little as 0.01°C over a > 10°C temperature range. The remarkable thermosensory abilities of this animal are mediated primarily via the single pair of AFD sensory neurons in its head. In this review, we describe the contributions of AFD to thermosensory behaviors and temperature-dependent regulation of organismal physiology. We also discuss the mechanisms that enable this neuron type to adapt to recent temperature experience and to exhibit extraordinary thermosensitivity over a wide dynamic range.
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Early Pheromone Experience Modifies a Synaptic Activity to Influence Adult Pheromone Responses of C. elegans. Curr Biol 2017; 27:3168-3177.e3. [PMID: 28988862 DOI: 10.1016/j.cub.2017.08.068] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 08/07/2017] [Accepted: 08/29/2017] [Indexed: 11/21/2022]
Abstract
Experiences during early development can influence neuronal functions and modulate adult behaviors [1, 2]. However, the molecular mechanisms underlying the long-term behavioral effects of these early experiences are not fully understood. The C. elegans ascr#3 (asc-ΔC9; C9) pheromone triggers avoidance behavior in adult hermaphrodites [3-7]. Here, we show that hermaphrodites that are briefly exposed to ascr#3 immediately after birth exhibit increased ascr#3-specific avoidance as adults, indicating that ascr#3-experienced animals form a long-lasting memory or imprint of this early ascr#3 exposure [8]. ascr#3 imprinting is mediated by increased synaptic activity between the ascr#3-sensing ADL neurons and their post-synaptic SMB motor neuron partners via increased expression of the odr-2 glycosylated phosphatidylinositol (GPI)-linked signaling gene in the SMB neurons. Our study suggests that the memory for early ascr#3 experience is imprinted via alteration of activity of a single synaptic connection, which in turn shapes experience-dependent plasticity in adult ascr#3 responses.
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Multiple Signaling Pathways Coordinately Regulate Forgetting of Olfactory Adaptation through Control of Sensory Responses in Caenorhabditis elegans. J Neurosci 2017; 37:10240-10251. [PMID: 28924007 DOI: 10.1523/jneurosci.0031-17.2017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 09/04/2017] [Indexed: 01/08/2023] Open
Abstract
Forgetting memories is important for animals to properly respond to continuously changing environments. To elucidate the mechanisms of forgetting, we used one of the behavioral plasticities of Caenorhabditis elegans hermaphrodite, olfactory adaptation to an attractive odorant, diacetyl, as a simple model of learning. In C. elegans, the TIR-1/JNK-1 pathway accelerates forgetting of olfactory adaptation by facilitating neural secretion from AWC sensory neurons. In this study, to identify the downstream effectors of the TIR-1/JNK-1 pathway, we conducted a genetic screen for suppressors of the gain-of-function mutant of tir-1 (ok1052), which shows excessive forgetting. Our screening showed that three proteins-a membrane protein, MACO-1; a receptor tyrosine kinase, SCD-2; and its putative ligand, HEN-1-regulated forgetting downstream of the TIR-1/JNK-1 pathway. We further demonstrated that MACO-1 and SCD-2/HEN-1 functioned in parallel genetic pathways, and only MACO-1 regulated forgetting of olfactory adaptation to isoamyl alcohol, which is an attractive odorant sensed by different types of sensory neurons. In olfactory adaptation, odor-evoked Ca2+ responses in olfactory neurons are attenuated by conditioning and recovered thereafter. A Ca2+ imaging study revealed that this attenuation is sustained longer in maco-1 and scd-2 mutant animals than in wild-type animals like the TIR-1/JNK-1 pathway mutants. Furthermore, temporal silencing by histamine-gated chloride channels revealed that the neuronal activity of AWC neurons after conditioning is important for proper forgetting. We propose that distinct signaling pathways, each of which has a specific function, may coordinately and temporally regulate forgetting by controlling sensory responses.SIGNIFICANCE STATEMENT Active forgetting is an important process to understand the whole mechanisms of memories. Recent papers have reported that the noncell autonomous regulations are required for proper forgetting in invertebrates. We found that in Caenorhabditis elegans hermaphrodite, the noncell autonomous regulations of forgetting of olfactory adaptation is regulated by three conserved proteins: a membrane protein, MACO-1; a receptor tyrosine kinase, SCD-2: and its ligand, HEN-1. MACO-1 and SCD-2/HEN-1, working in coordination, accelerate forgetting by controlling sensory responses in parallel. Furthermore, temporal regulation of neuronal activity is important for proper forgetting. We suggest that multiple pathways may coordinately and temporally regulate forgetting through control of sensory responses. This study should lead to a better understanding of forgetting in higher organisms.
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Contribution of the cyclic nucleotide gated channel subunit, CNG-3, to olfactory plasticity in Caenorhabditis elegans. Sci Rep 2017; 7:169. [PMID: 28279024 PMCID: PMC5427828 DOI: 10.1038/s41598-017-00126-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 02/08/2017] [Indexed: 11/08/2022] Open
Abstract
In Caenorhabditis elegans, the AWC neurons are thought to deploy a cGMP signaling cascade in the detection of and response to AWC sensed odors. Prolonged exposure to an AWC sensed odor in the absence of food leads to reversible decreases in the animal’s attraction to that odor. This adaptation exhibits two stages referred to as short-term and long-term adaptation. Previously, the protein kinase G (PKG), EGL-4/PKG-1, was shown necessary for both stages of adaptation and phosphorylation of its target, the beta-type cyclic nucleotide gated (CNG) channel subunit, TAX-2, was implicated in the short term stage. Here we uncover a novel role for the CNG channel subunit, CNG-3, in short term adaptation. We demonstrate that CNG-3 is required in the AWC for adaptation to short (thirty minute) exposures of odor, and contains a candidate PKG phosphorylation site required to tune odor sensitivity. We also provide in vivo data suggesting that CNG-3 forms a complex with both TAX-2 and TAX-4 CNG channel subunits in AWC. Finally, we examine the physiology of different CNG channel subunit combinations.
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Compartmentalized cGMP Responses of Olfactory Sensory Neurons in Caenorhabditis elegans. J Neurosci 2017; 37:3753-3763. [PMID: 28270568 DOI: 10.1523/jneurosci.2628-16.2017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 02/23/2017] [Accepted: 02/24/2017] [Indexed: 01/13/2023] Open
Abstract
Cyclic guanosine monophosphate (cGMP) plays a crucial role as a second messenger in the regulation of sensory signal transduction in many organisms. In AWC olfactory sensory neurons of Caenorhabditis elegans, cGMP also has essential and distinctive functions in olfactory sensation and adaptation. According to molecular genetic studies, when nematodes are exposed to odorants, a decrease in cGMP regulates cGMP-gated channels for olfactory sensation. Conversely, for olfactory adaptation, an increase in cGMP activates protein kinase G to modulate cellular physiological functions. Although these opposing cGMP responses in single neurons may occur at the same time, it is unclear how cGMP actually behaves in AWC sensory neurons. A hypothetical explanation for opposing cGMP responses is region-specific behaviors in AWC: for odor sensation, cGMP levels in cilia could decrease, whereas odor adaptation is mediated by increased cGMP levels in soma. Therefore, we visualized intracellular cGMP in AWC with a genetically encoded cGMP indicator, cGi500, and examined spatiotemporal cGMP responses in AWC neurons. The cGMP imaging showed that, after odor exposure, cGMP levels in AWC cilia decreased transiently, whereas levels in dendrites and soma gradually increased. These region-specific responses indicated that the cGMP responses in AWC neurons are explicitly compartmentalized. In addition, we performed Ca2+ imaging to examine the relationship between cGMP and Ca2+ These results suggested that AWC sensory neurons are in fact analogous to vertebrate photoreceptor neurons.SIGNIFICANCE STATEMENT Cyclic guanosine monophosphate (cGMP) plays crucial roles in the regulation of sensory signal transduction in many animals. In AWC olfactory sensory neurons of Caenorhabditis elegans, cGMP also has essential and distinctive functions involving olfactory sensation and adaptation. Here, we visualized intracellular cGMP in AWC neurons with a genetically encoded cGMP indicator and examined how these different functions could be regulated by the same second messenger in single neurons. cGMP imaging showed that, after odor application, cGMP levels in cilia decreased transiently, whereas levels in dendrites and soma gradually increased. These region-specific responses indicated that the responses in AWC neurons are explicitly compartmentalized. In addition, by combining cGMP and Ca2+ imaging, we observed that AWC neurons are analogous to vertebrate photoreceptor neurons.
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He C, Altshuler-Keylin S, Daniel D, L'Etoile ND, O'Halloran D. The cyclic nucleotide gated channel subunit CNG-1 instructs behavioral outputs in Caenorhabditis elegans by coincidence detection of nutritional status and olfactory input. Neurosci Lett 2016; 632:71-8. [PMID: 27561605 DOI: 10.1016/j.neulet.2016.08.037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 08/19/2016] [Accepted: 08/21/2016] [Indexed: 12/26/2022]
Abstract
In mammals, olfactory subsystems have been shown to express seven-transmembrane G-protein-coupled receptors (GPCRs) in a one-receptor-one-neuron pattern, whereas in Caenorhabditis elegans, olfactory sensory neurons express multiple G-protein coupled odorant receptors per olfactory sensory neuron. In both mammalian and C. elegans olfactory sensory neurons (OSNs), the process of olfactory adaptation begins within the OSN; this process of negative feedback within the mammalian OSN has been well described in mammals and enables activated OSNs to desensitize their response cell autonomously while attending to odors detected by separate OSNs. However, the mechanism that enables C. elegans to adapt to one odor and attend to another odor sensed by the same olfactory sensory neuron remains unclear. We found that the cyclic nucleotide gated channel subunit CNG-1 is required to promote cross adaptation responses between distinct olfactory cues. This change in sensitivity to a pair of odorants after persistent stimulation by just one of these odors is modulated by the internal nutritional state of the animal, and we find that this response is maintained across a diverse range of food sources for C. elegans. We also reveal that CNG-1 integrates food related cues for exploratory motor output, revealing that CNG-1 functions in multiple capacities to link nutritional information with behavioral output. Our data describes a novel model whereby CNG channels can integrate the coincidence detection of appetitive and olfactory information to set olfactory preferences and instruct behavioral outputs.
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Affiliation(s)
- Chao He
- Department of Biological Sciences, The George Washington University, Science and Engineering Hall 6000, 800 22nd St N.W., Washington DC, 20052, USA; Institute for Neuroscience, The George Washington University, 636 Ross Hall, 2300 I St. NW, Washington DC, 20052, USA
| | - Svetlana Altshuler-Keylin
- UCSF Diabetes Center, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, Department of Cell and Tissue Biology, University of California, San Francisco, CA 94143, USA
| | - David Daniel
- Department of Biological Sciences, The George Washington University, Science and Engineering Hall 6000, 800 22nd St N.W., Washington DC, 20052, USA; Institute for Neuroscience, The George Washington University, 636 Ross Hall, 2300 I St. NW, Washington DC, 20052, USA
| | - Noelle D L'Etoile
- Kavli Institute for Fundamental Neuroscience, Department of Cell and Tissue Biology, UCSF, 513 Parnassus Avenue HSW 717, UCSF, USA
| | - Damien O'Halloran
- Department of Biological Sciences, The George Washington University, Science and Engineering Hall 6000, 800 22nd St N.W., Washington DC, 20052, USA; Institute for Neuroscience, The George Washington University, 636 Ross Hall, 2300 I St. NW, Washington DC, 20052, USA.
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