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Das B, Madhubala D, Mahanta S, Patra A, Puzari U, Khan MR, Mukherjee AK. A Novel Therapeutic Formulation for the Improved Treatment of Indian Red Scorpion ( Mesobuthus tamulus) Venom-Induced Toxicity-Tested in Caenorhabditis elegans and Rodent Models. Toxins (Basel) 2023; 15:504. [PMID: 37624261 PMCID: PMC10467153 DOI: 10.3390/toxins15080504] [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: 06/03/2023] [Revised: 08/02/2023] [Accepted: 08/09/2023] [Indexed: 08/26/2023] Open
Abstract
Indian Red Scorpion (Mesobuthus tamulus) stings are a neglected public health problem in tropical and sub-tropical countries, including India. The drawbacks of conventional therapies using commercial anti-scorpion antivenom (ASA) and α1-adrenoreceptor antagonists (AAA) have prompted us to search for an adequate formulation to improve treatment against M. tamulus stings. Novel therapeutic drug formulations (TDF) of low doses of commercial ASA, AAA, and ascorbic acid have remarkably improved in neutralising the in vivo toxic effects of M. tamulus venom (MTV) tested in Caenorhabditis elegans and Wistar strain albino rats in vivo models. The neutralisation of MTV-induced production of free radicals, alteration of the mitochondrial transmembrane potential, and upregulated expression of genes involved in apoptosis, detoxification, and stress response in C. elegans by TDF surpassed the same effect shown by individual components of the TDF. Further, TDF efficiently neutralized the MTV-induced increase in blood glucose level within 30 to 60 min post-treatment, organ tissue damage, necrosis, and pulmonary oedema in Wistar rats, indicating its clinical application for effecting treating M. tamulus envenomation. This study demonstrates for the first time that C. elegans can be a model organism for screening the neutralization potency of the drug molecules against a neurotoxic scorpion venom.
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Affiliation(s)
- Bhabana Das
- Microbial Biotechnology and Protein Research Laboratory, Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur 784028, Assam, India; (B.D.); (D.M.); (U.P.)
| | - Dev Madhubala
- Microbial Biotechnology and Protein Research Laboratory, Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur 784028, Assam, India; (B.D.); (D.M.); (U.P.)
- Division of Life Sciences, Institute of Advanced Study in Science and Technology, Vigyan Path, Garchuk, Paschim Boragaon, Guwahati 781035, Assam, India; (A.P.); (M.R.K.)
| | - Saurov Mahanta
- National Institute of Electronics and Information Technology (NIELIT), Guwahati 781008, Assam, India;
| | - Aparup Patra
- Division of Life Sciences, Institute of Advanced Study in Science and Technology, Vigyan Path, Garchuk, Paschim Boragaon, Guwahati 781035, Assam, India; (A.P.); (M.R.K.)
| | - Upasana Puzari
- Microbial Biotechnology and Protein Research Laboratory, Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur 784028, Assam, India; (B.D.); (D.M.); (U.P.)
| | - Mojibur R. Khan
- Division of Life Sciences, Institute of Advanced Study in Science and Technology, Vigyan Path, Garchuk, Paschim Boragaon, Guwahati 781035, Assam, India; (A.P.); (M.R.K.)
| | - Ashis K. Mukherjee
- Microbial Biotechnology and Protein Research Laboratory, Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur 784028, Assam, India; (B.D.); (D.M.); (U.P.)
- Division of Life Sciences, Institute of Advanced Study in Science and Technology, Vigyan Path, Garchuk, Paschim Boragaon, Guwahati 781035, Assam, India; (A.P.); (M.R.K.)
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Tsai Y, Lin YC, Lee YH. Octopamine-MAPK-SKN-1 signaling suppresses mating-induced oxidative stress in Caenorhabditis elegans gonads to protect fertility. iScience 2023; 26:106162. [PMID: 36876134 PMCID: PMC9976470 DOI: 10.1016/j.isci.2023.106162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 12/12/2022] [Accepted: 02/02/2023] [Indexed: 02/11/2023] Open
Abstract
Sexual conflict over mating is costly to female physiology. Caenorhabditis elegans hermaphrodites generally produce self-progeny, but they can produce cross-progeny upon successfully mating with a male. We have uncovered that C. elegans hermaphrodites experience sexual conflict over mating, resulting in severe costs in terms of their fertility and longevity. We show that reactive oxygen species (ROS) accumulate on the apical surfaces of spermathecal bag cells after successful mating and induce cell damage, leading to ovulation defects and fertility suppression. To counteract these negative impacts, C. elegans hermaphrodites deploy the octopamine (OA) regulatory pathway to enhance glutathione (GSH) biosynthesis and protect spermathecae from mating-induced ROS. We show that the SER-3 receptor and mitogen-activated protein kinase (MAPK) KGB-1 cascade transduce the OA signal to transcription factor SKN-1/Nrf2 in the spermatheca to upregulate GSH biosynthesis.
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Affiliation(s)
- Yu Tsai
- Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan
| | - Yu-Chun Lin
- Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan
| | - Ying-Hue Lee
- Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan
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Olfactory perception of food abundance regulates dietary restriction-mediated longevity via a brain-to-gut signal. NATURE AGING 2021; 1:255-268. [PMID: 33796867 PMCID: PMC8009090 DOI: 10.1038/s43587-021-00039-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The role of food nutrients in mediating the positive effect of dietary restriction (DR) on longevity has been extensively characterized, but how non-nutrient food components regulate lifespan is not well understood. Here, we show that food-associated odors shorten the lifespan of C. elegans under DR but not those fed ad libitum, revealing a specific effect of food odors on DR-mediated longevity. Food odors act on a neural circuit comprising the sensory neurons ADF and CEP, and the interneuron RIC. This olfactory circuit signals the gut to suppress DR-mediated longevity via octopamine, the invertebrate homolog of norepinephrine, by regulating the energy sensor AMPK through a Gq-PLCβ-CaMKK-dependent mechanism. In mouse primary cells, we find that norepinephrine signaling regulates AMPK through a similar mechanism. Our results identify a brain-gut axis that regulates DR-mediated longevity by relaying olfactory information about food abundance from the brain to the gut.
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Malpe MS, McSwain LF, Kudyba K, Ng CL, Nicholson J, Brady M, Qian Y, Choksi V, Hudson AG, Parrott BB, Schulz C. G-protein signaling is required for increasing germline stem cell division frequency in response to mating in Drosophila males. Sci Rep 2020; 10:3888. [PMID: 32127590 PMCID: PMC7054589 DOI: 10.1038/s41598-020-60807-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 02/17/2020] [Indexed: 02/07/2023] Open
Abstract
Adult stem cells divide to renew the stem cell pool and replenish specialized cells that are lost due to death or usage. However, little is known about the mechanisms regulating how stem cells adjust to a demand for specialized cells. A failure of the stem cells to respond to this demand can have serious consequences, such as tissue loss, or prolonged recovery post injury. Here, we challenge the male germline stem cells (GSCs) of Drosophila melanogaster for the production of specialized cells, sperm cells, using mating experiments. We show that repeated mating reduced the sperm pool and increased the percentage of GSCs in M- and S-phase of the cell cycle. The increase in dividing GSCs depended on the activity of the highly conserved G-proteins. Germline expression of RNA-Interference (RNA-i) constructs against G-proteins, or a dominant negative G-protein eliminated the increase in GSC division frequency in mated males. Consistent with a role for the G-proteins in regulating GSC division frequency, RNA-i against seven out of 35 G-protein coupled receptors (GPCRs) within the germline cells also eliminated the capability of males to increase the numbers of dividing GSCs in response to mating.
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Affiliation(s)
- Manashree S Malpe
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Leon F McSwain
- Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
| | - Karl Kudyba
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Chun L Ng
- University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jennie Nicholson
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Maximilian Brady
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Yue Qian
- University of North Georgia, Department of Biology, Oakwood, GA, 30566, USA
| | - Vinay Choksi
- School of Medicine, Duke University, Durham, NC, 27708, USA
| | - Alicia G Hudson
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | | | - Cordula Schulz
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA.
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Chute CD, DiLoreto EM, Zhang YK, Reilly DK, Rayes D, Coyle VL, Choi HJ, Alkema MJ, Schroeder FC, Srinivasan J. Co-option of neurotransmitter signaling for inter-organismal communication in C. elegans. Nat Commun 2019; 10:3186. [PMID: 31320626 PMCID: PMC6639374 DOI: 10.1038/s41467-019-11240-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 06/28/2019] [Indexed: 12/22/2022] Open
Abstract
Biogenic amine neurotransmitters play a central role in metazoan biology, and both their chemical structures and cognate receptors are evolutionarily conserved. Their primary roles are in cell-to-cell signaling, as biogenic amines are not normally recruited for communication between separate individuals. Here, we show that in the nematode C. elegans, a neurotransmitter-sensing G protein-coupled receptor, TYRA-2, is required for avoidance responses to osas#9, an ascaroside pheromone that incorporates the neurotransmitter, octopamine. Neuronal ablation, cell-specific genetic rescue, and calcium imaging show that tyra-2 expression in the nociceptive neuron, ASH, is necessary and sufficient to induce osas#9 avoidance. Ectopic expression in the AWA neuron, which is generally associated with attractive responses, reverses the response to osas#9, resulting in attraction instead of avoidance behavior, confirming that TYRA-2 partakes in the sensing of osas#9. The TYRA-2/osas#9 signaling system represents an inter-organismal communication channel that evolved via co-option of a neurotransmitter and its cognate receptor.
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Affiliation(s)
- Christopher D Chute
- Biology and Biotechnology Department, Worcester Polytechnic Institute, Worcester, MA, 01605, USA
- BioHelix Corporation, Beverly, MA, 01915, USA
| | - Elizabeth M DiLoreto
- Biology and Biotechnology Department, Worcester Polytechnic Institute, Worcester, MA, 01605, USA
| | - Ying K Zhang
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Douglas K Reilly
- Biology and Biotechnology Department, Worcester Polytechnic Institute, Worcester, MA, 01605, USA
| | - Diego Rayes
- Neurobiology Department, University of Massachusetts Medical School, Worcester, MA, 01605, USA
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (CONICET), Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, B8000, Argentina
| | - Veronica L Coyle
- Biology and Biotechnology Department, Worcester Polytechnic Institute, Worcester, MA, 01605, USA
- AbbVie, Cambridge, MA, 02139, USA
| | - Hee June Choi
- Biomedical Engineering Department, Worcester Polytechnic Institute, Worcester, MA, 01605, USA
| | - Mark J Alkema
- Neurobiology Department, University of Massachusetts Medical School, Worcester, MA, 01605, USA
| | - Frank C Schroeder
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Jagan Srinivasan
- Biology and Biotechnology Department, Worcester Polytechnic Institute, Worcester, MA, 01605, USA.
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Suo S, Harada K, Matsuda S, Kyo K, Wang M, Maruyama K, Awaji T, Tsuboi T. Sexually Dimorphic Regulation of Behavioral States by Dopamine in Caenorhabditis elegans. J Neurosci 2019; 39:4668-4683. [PMID: 30988167 PMCID: PMC6561698 DOI: 10.1523/jneurosci.2985-18.2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Revised: 03/22/2019] [Accepted: 03/26/2019] [Indexed: 11/21/2022] Open
Abstract
Sex differences in behavior allow animals to effectively mate and reproduce. However, the mechanism by which biological sex regulates behavioral states, which underlie the regulation of sex-shared behaviors, such as locomotion, is largely unknown. In this study, we studied sex differences in the behavioral states of Caenorhabditis elegans and found that males spend less time in a low locomotor activity state than hermaphrodites and that dopamine generates this sex difference. In males, dopamine reduces the low activity state by acting in the same pathway as polycystic kidney disease-related genes that function in male-specific neurons. In hermaphrodites, dopamine increases the low activity state by suppression of octopamine signaling in the sex-shared SIA neurons, which have reduced responsiveness to octopamine in males. Furthermore, dopamine promotes exploration both inside and outside of bacterial lawn (the food source) in males and suppresses it in hermaphrodites. These results demonstrate that sexually dimorphic signaling allows the same neuromodulator to promote adaptive behavior for each sex.SIGNIFICANCE STATEMENT The mechanisms that generate sex differences in sex-shared behaviors, including locomotion, are not well understood. We show that there are sex differences in the regulation of behavioral states in the model animal Caenorhabditis elegans Dopamine promotes the high locomotor activity state in males, which must search for mates to reproduce, and suppresses it in self-fertilizing hermaphrodites through distinct molecular mechanisms. This study demonstrates that sex-specific signaling generates sex differences in the regulation of behavioral states, which in turn modulates the locomotor activity to suit reproduction for each sex.
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Affiliation(s)
- Satoshi Suo
- Department of Pharmacology, Faculty of Medicine, Saitama Medical University, Saitama, 350-0495, Japan,
| | - Kazuki Harada
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Tokyo, 153-8902, Japan
| | - Shogo Matsuda
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Tokyo, 113-0033, Japan, and
| | - Koki Kyo
- Department of Human Sciences, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido, 080-8555, Japan
| | - Min Wang
- Department of Pharmacology, Faculty of Medicine, Saitama Medical University, Saitama, 350-0495, Japan
| | - Kei Maruyama
- Department of Pharmacology, Faculty of Medicine, Saitama Medical University, Saitama, 350-0495, Japan
| | - Takeo Awaji
- Department of Pharmacology, Faculty of Medicine, Saitama Medical University, Saitama, 350-0495, Japan
| | - Takashi Tsuboi
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Tokyo, 153-8902, Japan
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Tokyo, 113-0033, Japan, and
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Reciprocal modulation of 5-HT and octopamine regulates pumping via feedforward and feedback circuits in C. elegans. Proc Natl Acad Sci U S A 2019; 116:7107-7112. [PMID: 30872487 PMCID: PMC6452730 DOI: 10.1073/pnas.1819261116] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Physiological regulation and behavior depend less on neurons than on neuronal circuits. Neurosignal integration is the basis of neurocircuit function. The modalities of neuroinformation integration are evolutionarily conserved in animals and humans. Here, we identified two modalities of neurosignal integration in two different circuits by which serotonergic ADFs regulate pharyngeal pumping in Caenorhabditis elegans: disinhibition in a feedforward circuit consisting of ADF, RIC, and SIA neurons and disexcitation, a modality of neurosignal integration suggested by this study, in a feedback circuit consisting of ADF, RIC, AWB, and ADF neurons. Feeding is vital for animal survival and is tightly regulated by the endocrine and nervous systems. To study the mechanisms of humoral regulation of feeding behavior, we investigated serotonin (5-HT) and octopamine (OA) signaling in Caenorhabditis elegans, which uses pharyngeal pumping to ingest bacteria into the gut. We reveal that a cross-modulation mechanism between 5-HT and OA, which convey feeding and fasting signals, respectively, mainly functions in regulating the pumping and secretion of both neuromodulators via ADF/RIC/SIA feedforward neurocircuit (consisting of ADF, RIC, and SIA neurons) and ADF/RIC/AWB/ADF feedback neurocircuit (consisting of ADF, RIC, AWB, and ADF neurons) under conditions of food supply and food deprivation, respectively. Food supply stimulates food-sensing ADFs to release more 5-HT, which augments pumping via inhibiting OA secretion by RIC interneurons and, thus, alleviates pumping suppression by OA-activated SIA interneurons/motoneurons. In contrast, nutrient deprivation stimulates RICs to secrete OA, which suppresses pumping via activating SIAs and maintains basal pumping and 5-HT production activity through excitation of ADFs relayed by AWB sensory neurons. Notably, the feedforward and feedback circuits employ distinct modalities of neurosignal integration, namely, disinhibition and disexcitation, respectively.
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Feeding state sculpts a circuit for sensory valence in Caenorhabditis elegans. Proc Natl Acad Sci U S A 2019; 116:1776-1781. [PMID: 30651312 DOI: 10.1073/pnas.1807454116] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Hunger affects the behavioral choices of all animals, and many chemosensory stimuli can be either attractive or repulsive depending on an animal's hunger state. Although hunger-induced behavioral changes are well documented, the molecular and cellular mechanisms by which hunger modulates neural circuit function to generate changes in chemosensory valence are poorly understood. Here, we use the CO2 response of the free-living nematode Caenorhabditis elegans to elucidate how hunger alters valence. We show that CO2 response valence shifts from aversion to attraction during starvation, a change that is mediated by two pairs of interneurons in the CO2 circuit, AIY and RIG. The transition from aversion to attraction is regulated by biogenic amine signaling. Dopamine promotes CO2 repulsion in well-fed animals, whereas octopamine promotes CO2 attraction in starved animals. Biogenic amines also regulate the temporal dynamics of the shift from aversion to attraction such that animals lacking octopamine show a delayed shift to attraction. Biogenic amine signaling regulates CO2 response valence by modulating the CO2-evoked activity of AIY and RIG. Our results illuminate a new role for biogenic amine signaling in regulating chemosensory valence as a function of hunger state.
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Koelle MR. Neurotransmitter signaling through heterotrimeric G proteins: insights from studies in C. elegans. WORMBOOK : THE ONLINE REVIEW OF C. ELEGANS BIOLOGY 2018; 2018:1-52. [PMID: 26937633 PMCID: PMC5010795 DOI: 10.1895/wormbook.1.75.2] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Neurotransmitters signal via G protein coupled receptors (GPCRs) to modulate activity of neurons and muscles. C. elegans has ∼150 G protein coupled neuropeptide receptor homologs and 28 additional GPCRs for small-molecule neurotransmitters. Genetic studies in C. elegans demonstrate that neurotransmitters diffuse far from their release sites to activate GPCRs on distant cells. Individual receptor types are expressed on limited numbers of cells and thus can provide very specific regulation of an individual neural circuit and behavior. G protein coupled neurotransmitter receptors signal principally via the three types of heterotrimeric G proteins defined by the G alpha subunits Gαo, Gαq, and Gαs. Each of these G alpha proteins is found in all neurons plus some muscles. Gαo and Gαq signaling inhibit and activate neurotransmitter release, respectively. Gαs signaling, like Gαq signaling, promotes neurotransmitter release. Many details of the signaling mechanisms downstream of Gαq and Gαs have been delineated and are consistent with those of their mammalian orthologs. The details of the signaling mechanism downstream of Gαo remain a mystery. Forward genetic screens in C. elegans have identified new molecular components of neural G protein signaling mechanisms, including Regulators of G protein Signaling (RGS proteins) that inhibit signaling, a new Gαq effector (the Trio RhoGEF domain), and the RIC-8 protein that is required for neuronal Gα signaling. A model is presented in which G proteins sum up the variety of neuromodulator signals that impinge on a neuron to calculate its appropriate output level.
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Affiliation(s)
- Michael R Koelle
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven CT 06520 USA
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Liu X, Chen X, Liu H, Cao Y. Antioxidation and anti-aging activities of astaxanthin geometrical isomers and molecular mechanism involved in Caenorhabditis elegans. J Funct Foods 2018. [DOI: 10.1016/j.jff.2018.03.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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Antagonistic Serotonergic and Octopaminergic Neural Circuits Mediate Food-Dependent Locomotory Behavior in Caenorhabditis elegans. J Neurosci 2017; 37:7811-7823. [PMID: 28698386 DOI: 10.1523/jneurosci.2636-16.2017] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 05/18/2017] [Accepted: 07/01/2017] [Indexed: 11/21/2022] Open
Abstract
Biogenic amines are conserved signaling molecules that link food cues to behavior and metabolism in a wide variety of organisms. In the nematode Caenorhabditis elegans, the biogenic amines serotonin (5-HT) and octopamine regulate a number of food-related behaviors. Using a novel method for long-term quantitative behavioral imaging, we show that 5-HT and octopamine jointly influence locomotor activity and quiescence in feeding and fasting hermaphrodites, and we define the neural circuits through which this modulation occurs. We show that 5-HT produced by the ADF neurons acts via the SER-5 receptor in muscles and neurons to suppress quiescent behavior and promote roaming in fasting worms, whereas 5-HT produced by the NSM neurons acts on the MOD-1 receptor in AIY neurons to promote low-amplitude locomotor behavior characteristic of well fed animals. Octopamine, produced by the RIC neurons, acts via SER-3 and SER-6 receptors in SIA neurons to promote roaming behaviors characteristic of fasting animals. We find that 5-HT signaling is required for animals to assume food-appropriate behavior, whereas octopamine signaling is required for animals to assume fasting-appropriate behavior. The requirement for both neurotransmitters in both the feeding and fasting states enables increased behavioral adaptability. Our results define the molecular and neural pathways through which parallel biogenic amine signaling tunes behavior appropriately to nutrient conditions.SIGNIFICANCE STATEMENT Animals adjust behavior in response to environmental changes, such as fluctuations in food abundance, to maximize survival and reproduction. Biogenic amines, such as like serotonin, are conserved neurotransmitters that regulate behavior and metabolism in relation to energy status. Disruptions of biogenic amine signaling contribute to human neurological diseases of mood, appetite, and movement. In this study, we investigated the roles of the biogenic amines serotonin and octopamine in regulating locomotion behaviors associated with feeding and fasting in the roundworm Caenorhabditis elegans We identified neural circuits through which these signals work to govern behavior. Understanding the molecular pathways through which biogenic amines function in model organisms may improve our understanding of dysfunctions of appetite and behavior found in mammals, including humans.
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Dopamine regulates body size in Caenorhabditis elegans. Dev Biol 2016; 412:128-138. [DOI: 10.1016/j.ydbio.2016.02.021] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 01/08/2016] [Accepted: 02/23/2016] [Indexed: 12/31/2022]
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13
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Dallière N, Bhatla N, Luedtke Z, Ma DK, Woolman J, Walker RJ, Holden-Dye L, O'Connor V. Multiple excitatory and inhibitory neural signals converge to fine-tune Caenorhabditis elegans feeding to food availability. FASEB J 2015; 30:836-48. [PMID: 26514165 DOI: 10.1096/fj.15-279257] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 10/13/2015] [Indexed: 01/02/2023]
Abstract
How an animal matches feeding to food availability is a key question for energy homeostasis. We addressed this in the nematode Caenorhabditis elegans, which couples feeding to the presence of its food (bacteria) by regulating pharyngeal activity (pumping). We scored pumping in the presence of food and over an extended time course of food deprivation in wild-type and mutant worms to determine the neural substrates of adaptive behavior. Removal of food initially suppressed pumping but after 2 h this was accompanied by intermittent periods of high activity. We show pumping is fine-tuned by context-specific neural mechanisms and highlight a key role for inhibitory glutamatergic and excitatory cholinergic/peptidergic drives in the absence of food. Additionally, the synaptic protein UNC-31 [calcium-activated protein for secretion (CAPS)] acts through an inhibitory pathway not explained by previously identified contributions of UNC-31/CAPS to neuropeptide or glutamate transmission. Pumping was unaffected by laser ablation of connectivity between the pharyngeal and central nervous system indicating signals are either humoral or intrinsic to the enteric system. This framework in which control is mediated through finely tuned excitatory and inhibitory drives resonates with mammalian hypothalamic control of feeding and suggests that fundamental regulation of this basic animal behavior may be conserved through evolution from nematode to human.
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Affiliation(s)
- Nicolas Dallière
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Nikhil Bhatla
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Zara Luedtke
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Dengke K Ma
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Jonathan Woolman
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Robert J Walker
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Lindy Holden-Dye
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Vincent O'Connor
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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