1
|
Bechtel W, Bich L. Using neurons to maintain autonomy: Learning from C. elegans. Biosystems 2023; 232:105017. [PMID: 37666409 DOI: 10.1016/j.biosystems.2023.105017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 08/29/2023] [Accepted: 08/29/2023] [Indexed: 09/06/2023]
Abstract
Understanding how biological organisms are autonomous-maintain themselves far from equilibrium through their own activities-requires understanding how they regulate those activities. In multicellular animals, such control can be exercised either via endocrine signaling through the vasculature or via neurons. In C. elegans this control is exercised by a well-delineated relatively small but distributed nervous system that relies on both chemical and electric transmission of signals. This system provides resources to integrate information from multiple sources as needed to maintain the organism. Especially important for the exercise of neural control are neuromodulators, which we present as setting agendas for control through more traditional electrical signaling. To illustrate how the C. elegans nervous system integrates multiple sources of information in controlling activities important for autonomy, we focus on feeding behavior and responses to adverse conditions. We conclude by considering how a distributed nervous system without a centralized controller is nonetheless adequate for autonomy.
Collapse
Affiliation(s)
- William Bechtel
- Department of Philosophy; University of California, San Diego; La Jolla, CA 92093-0119, USA.
| | - Leonardo Bich
- IAS-Research Centre for Life, Mind and Society; Department of Philosophy; University of the Basque Country (UPV/EHU); Avenida de Tolosa 70; Donostia-San Sebastian, 20018; Spain.
| |
Collapse
|
2
|
Deshe N, Eliezer Y, Hoch L, Itskovits E, Bokman E, Ben-Ezra S, Zaslaver A. Inheritance of associative memories and acquired cellular changes in C. elegans. Nat Commun 2023; 14:4232. [PMID: 37454110 PMCID: PMC10349803 DOI: 10.1038/s41467-023-39804-8] [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: 11/12/2020] [Accepted: 06/27/2023] [Indexed: 07/18/2023] Open
Abstract
Experiences have been shown to modulate behavior and physiology of future generations in some contexts, but there is limited evidence for inheritance of associative memory in different species. Here, we trained C. elegans nematodes to associate an attractive odorant with stressful starvation conditions and revealed that this associative memory was transmitted to the F1 progeny who showed odor-evoked avoidance behavior. Moreover, the F1 and the F2 descendants of trained animals exhibited odor-evoked cellular stress responses, manifested by the translocation of DAF-16/FOXO to cells' nuclei. Sperm, but not oocytes, transmitted these odor-evoked cellular stress responses which involved H3K9 and H3K36 methylations, the small RNA pathway machinery, and intact neuropeptide secretion. Activation of a single chemosensory neuron sufficed to induce a serotonin-mediated systemic stress response in both the parental trained generation and in its progeny. Moreover, inheritance of the cellular stress responses increased survival chances of the progeny as exposure to the training odorant allowed the animals to prepare in advance for an impending adversity. These findings suggest that in C. elegans associative memories and cellular changes may be transferred across generations.
Collapse
Affiliation(s)
- Noa Deshe
- Department of Genetics, Silberman Institute of Life Science, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
| | - Yifat Eliezer
- Department of Genetics, Silberman Institute of Life Science, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
| | - Lihi Hoch
- Department of Genetics, Silberman Institute of Life Science, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
| | - Eyal Itskovits
- Department of Genetics, Silberman Institute of Life Science, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
| | - Eduard Bokman
- Department of Genetics, Silberman Institute of Life Science, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
| | - Shachaf Ben-Ezra
- Department of Genetics, Silberman Institute of Life Science, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
| | - Alon Zaslaver
- Department of Genetics, Silberman Institute of Life Science, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel.
| |
Collapse
|
3
|
Ramanayake-Mudiyanselage V, Embogama DM, Pflum MKH. Kinase-Catalyzed Biotinylation to Map Cell Signaling Pathways: Application to Epidermal Growth Factor Signaling. J Proteome Res 2021; 20:4852-4861. [PMID: 34491762 DOI: 10.1021/acs.jproteome.1c00562] [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] [Indexed: 11/30/2022]
Abstract
Cell signaling involves a network of protein-protein interactions and post-translational modifications that govern cellular responses to environmental cues. To understand and ultimately modulate these signaling pathways to confront disease, the complex web of proteins that becomes phosphorylated after extracellular stimulation has been studied using mass spectrometry-based proteomics methods. To complement prior work and fully characterize all phosphorylated proteins after the stimulation of cell signaling, we developed K-BMAPS (kinase-catalyzed biotinylation to map signaling), which utilizes ATP-biotin as a kinase cosubstrate to biotin label substrates. As a first application of the K-BMAPS method, the well-characterized epidermal growth factor receptor (EGFR) kinase signaling pathway was monitored by treating epidermal growth factor (EGF)-stimulated HeLa lysates with ATP-biotin, followed by streptavidin enrichment and quantitative mass spectrometry analysis. On the basis of the dynamic phosphoproteins identified, a pathway map was developed considering functional categories and known interactors of EGFR. Remarkably, 94% of the K-BMAPS hit proteins were included in the EGFR pathway map. With many proteins involved in transcription, translation, cell adhesion, and GTPase signaling, K-BMAPS identified phosphoproteins were associated with late and continuous signaling events. In summary, the K-BMAPS method is a powerful tool to map the dynamic phosphorylation governing cell signaling pathways.
Collapse
Affiliation(s)
| | - D Maheeka Embogama
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, Michigan 48202, United States
| | - Mary Kay H Pflum
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, Michigan 48202, United States
| |
Collapse
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
Abstract
I review the history of sleep research in Caenorhabditis elegans, briefly introduce the four articles in this issue focused on worm sleep and propose future directions our field might take.
Collapse
Affiliation(s)
- David Raizen
- Neurology, University of Pennsylvania, Philadelphia, PA, USA
| |
Collapse
|
6
|
Goetting DL, Mansfield R, Soto R, Buskirk CV. Cellular damage, including wounding, drives C. elegans stress-induced sleep. J Neurogenet 2020; 34:430-439. [PMID: 32362197 DOI: 10.1080/01677063.2020.1752203] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Across animal phyla, sleep is associated with increased cellular repair, suggesting that cellular damage may be a core component of sleep pressure. In support of this notion, sleep in the nematode Caenorhabditis elegans can be triggered by damaging conditions, including noxious heat, high salt, and ultraviolet light exposure. It is not clear, however, whether this stress-induced sleep (SIS) is a direct consequence of cellular damage, or of a resulting energy deficit, or whether it is triggered simply by the sensation of noxious conditions. Here, we show that thermosensation is dispensable for heat-induced sleep, that osmosensation is dispensable for salt-induced sleep, and that wounding is also a sleep trigger, together indicating that SIS is not triggered by sensation of noxious environments. We present evidence that genetic variation in cellular repair pathways impacts sleep amount, and that SIS involves systemic monitoring of cellular damage. We show that the low-energy sensor AMP-activated protein kinase (AMPK) is not required for SIS, suggesting that energy deficit is not the primary sleep trigger. Instead, AMPK-deficient animals display enhanced SIS responses, and pharmacological activation of AMPK reduces SIS, suggesting that ATP-dependent repair of cellular damage mitigates sleep pressure.
Collapse
Affiliation(s)
- Desiree L Goetting
- Department of Biology, California State University Northridge, Los Angeles, CA, USA
| | - Richard Mansfield
- Department of Biology, California State University Northridge, Los Angeles, CA, USA
| | - Rony Soto
- Department of Biology, California State University Northridge, Los Angeles, CA, USA
| | - Cheryl Van Buskirk
- Department of Biology, California State University Northridge, Los Angeles, CA, USA
| |
Collapse
|
7
|
McClanahan PD, Dubuque JM, Kontogiorgos-Heintz D, Habermeyer BF, Xu JH, Ma AM, Raizen DM, Fang-Yen C. A quiescent state following mild sensory arousal in Caenorhabditis elegans is potentiated by stress. Sci Rep 2020; 10:4140. [PMID: 32139752 PMCID: PMC7057961 DOI: 10.1038/s41598-020-60994-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Accepted: 02/14/2020] [Indexed: 11/16/2022] Open
Abstract
An animal's behavioral and physiological response to stressors includes changes to its responses to stimuli. How such changes occur is not well understood. Here we describe a Caenorhabditis elegans quiescent behavior, post-response quiescence (PRQ), which is modulated by the C. elegans response to cellular stressors. Following an aversive mechanical or blue light stimulus, worms respond first by briefly moving, and then become more quiescent for a period lasting tens of seconds. PRQ occurs at low frequency in unstressed animals, but is more frequent in animals that have experienced cellular stress due to ultraviolet light exposure as well as in animals following overexpression of epidermal growth factor (EGF). PRQ requires the function of the carboxypeptidase EGL-21 and the calcium-activated protein for secretion (CAPS) UNC-31, suggesting it has a neuropeptidergic mechanism. Although PRQ requires the sleep-promoting neurons RIS and ALA, it is not accompanied by decreased arousability, and does not appear to be homeostatically regulated, suggesting that it is not a sleep state. PRQ represents a simple, tractable model for studying how neuromodulatory states like stress alter behavioral responses to stimuli.
Collapse
Affiliation(s)
- Patrick D. McClanahan
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA USA
| | - Jessica M. Dubuque
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA USA
| | - Daphne Kontogiorgos-Heintz
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA USA
| | - Ben F. Habermeyer
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA USA
| | - Joyce H. Xu
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA USA
| | - Anthony M. Ma
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA USA
| | - David M. Raizen
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
| | - Christopher Fang-Yen
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA USA
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
| |
Collapse
|
8
|
Soto R, Goetting DL, Van Buskirk C. NPR-1 Modulates Plasticity in C. elegans Stress-Induced Sleep. iScience 2019; 19:1037-1047. [PMID: 31522115 PMCID: PMC6745490 DOI: 10.1016/j.isci.2019.08.050] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 08/22/2019] [Accepted: 08/27/2019] [Indexed: 12/15/2022] Open
Abstract
Sleep is beneficial yet antagonistic to critical functions such as foraging and escape, and we aim to understand how these competing drives are functionally integrated. C. elegans, which lives in reduced oxygen environments, engages in developmentally timed sleep (DTS) during larval stage transitions and engages in stress-induced sleep (SIS) during recovery from damaging conditions. Although DTS and SIS use distinct mechanisms to coordinate multiple sleep-associated behaviors, we show that movement quiescence in these sleep states is similarly integrated with the competing drive to avoid oxygen. Furthermore, by manipulating oxygen to deprive animals of SIS, we observe sleep rebound in a wild C. elegans isolate, indicating that sleep debt accrues during oxygen-induced SIS deprivation. Our work suggests that multiple sleep states adopt a common, highly plastic effector of movement quiescence that is suppressed by aversive stimuli and responsive to homeostatic sleep pressure, providing a limited window of opportunity for escape.
Collapse
Affiliation(s)
- Rony Soto
- Department of Biology, California State University Northridge, Northridge, CA 91330, USA
| | - Desiree L Goetting
- Department of Biology, California State University Northridge, Northridge, CA 91330, USA
| | - Cheryl Van Buskirk
- Department of Biology, California State University Northridge, Northridge, CA 91330, USA.
| |
Collapse
|
9
|
The Vav GEF Family: An Evolutionary and Functional Perspective. Cells 2019; 8:cells8050465. [PMID: 31100928 PMCID: PMC6562523 DOI: 10.3390/cells8050465] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 05/10/2019] [Accepted: 05/15/2019] [Indexed: 02/07/2023] Open
Abstract
Vav proteins play roles as guanosine nucleotide exchange factors for Rho GTPases and signaling adaptors downstream of protein tyrosine kinases. The recent sequencing of the genomes of many species has revealed that this protein family originated in choanozoans, a group of unicellular organisms from which animal metazoans are believed to have originated from. Since then, the Vav family underwent expansions and reductions in its members during the evolutionary transitions that originated the agnates, chondrichthyes, some teleost fish, and some neoaves. Exotic members of the family harboring atypical structural domains can be also found in some invertebrate species. In this review, we will provide a phylogenetic perspective of the evolution of the Vav family. We will also pay attention to the structure, signaling properties, regulatory layers, and functions of Vav proteins in both invertebrate and vertebrate species.
Collapse
|
10
|
Huang H, Zhu Y, Eliot MN, Knopik VS, McGeary JE, Carskadon MA, Hart AC. Combining Human Epigenetics and Sleep Studies in Caenorhabditis elegans: A Cross-Species Approach for Finding Conserved Genes Regulating Sleep. Sleep 2018; 40:3738764. [PMID: 28431118 DOI: 10.1093/sleep/zsx063] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Study Objectives We aimed to test a combined approach to identify conserved genes regulating sleep and to explore the association between DNA methylation and sleep length. Methods We identified candidate genes associated with shorter versus longer sleep duration in college students based on DNA methylation using Illumina Infinium HumanMethylation450 BeadChip arrays. Orthologous genes in Caenorhabditis elegans were identified, and we examined whether their loss of function affected C. elegans sleep. For genes whose perturbation affected C. elegans sleep, we subsequently undertook a small pilot study to re-examine DNA methylation in an independent set of human participants with shorter versus longer sleep durations. Results Eighty-seven out of 485,577 CpG sites had significant differential methylation in young adults with shorter versus longer sleep duration, corresponding to 52 candidate genes. We identified 34 C. elegans orthologs, including NPY/flp-18 and flp-21, which are known to affect sleep. Loss of five additional genes alters developmentally timed C. elegans sleep (B4GALT6/bre-4, DOCK180/ced-5, GNB2L1/rack-1, PTPRN2/ida-1, ZFYVE28/lst-2). For one of these genes, ZFYVE28 (also known as hLst2), the pilot replication study again found decreased DNA methylation associated with shorter sleep duration at the same two CpG sites in the first intron of ZFYVE28. Conclusions Using an approach that combines human epigenetics and C. elegans sleep studies, we identified five genes that play previously unidentified roles in C. elegans sleep. We suggest sleep duration in humans may be associated with differential DNA methylation at specific sites and that the conserved genes identified here likely play roles in C. elegans sleep and in other species.
Collapse
Affiliation(s)
- Huiyan Huang
- Department of Neuroscience, Brown University, Providence, RI
| | - Yong Zhu
- Department of Environmental Health Sciences, Yale University School of Public Health, New Haven, CT
| | - Melissa N Eliot
- Department of Epidemiology, Brown University, Providence, RI
| | - Valerie S Knopik
- Division of Behavioral Genetics, Department of Psychiatry, Rhode Island Hospital, Providence, RI.,Department of Psychiatry and Human Behavior, Brown University, Providence, RI
| | - John E McGeary
- Division of Behavioral Genetics, Department of Psychiatry, Rhode Island Hospital, Providence, RI.,Department of Psychiatry and Human Behavior, Brown University, Providence, RI.,Providence Veterans Affairs Medical Center, Providence, RI
| | - Mary A Carskadon
- Department of Psychiatry and Human Behavior, Brown University, Providence, RI.,E.P. Bradley Hospital Sleep Research Laboratory, Providence, RI.,Center for Sleep Research, University of South Australia, Adelaide, Australia
| | - Anne C Hart
- Department of Neuroscience, Brown University, Providence, RI
| |
Collapse
|
11
|
李 勇, 檀 碧. Vav基因家族的分子调控机制及其与消化系恶性肿瘤的关系. Shijie Huaren Xiaohua Zazhi 2017; 25:2102-2108. [DOI: 10.11569/wcjd.v25.i23.2102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Vav基因家族包括Vav1、Vav2、Vav3基因, 在生理及病理过程中都发挥着重要的调控作用. 近年来发现Vav基因家族成员与消化系恶性肿瘤有较为密切的关系, 已取得了一些研究成果. 但迄今为止有关Vav基因家族成员与消化系恶性肿瘤关系的研究还不全面, 且有一些结果不一致. 因此, 总结Vav基因家族成员的调控机制并分析其在消化系恶性肿瘤中发挥的作用有可能对阐明发病机制、提出新的治疗靶点有益. 故本文对Vav基因家族的分子功能、调控机制及在消化系恶性肿瘤中的作用进行了综述及总结, 并对该基因家族的潜在价值进行了预测.
Collapse
|
12
|
Stress-Induced Sleep After Exposure to Ultraviolet Light Is Promoted by p53 in Caenorhabditis elegans. Genetics 2017; 207:571-582. [PMID: 28754659 DOI: 10.1534/genetics.117.300070] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 07/24/2017] [Indexed: 12/31/2022] Open
Abstract
Stress-induced sleep (SIS) in Caenorhabditis elegans is important for restoration of cellular homeostasis and is a useful model to study the function and regulation of sleep. SIS is triggered when epidermal growth factor (EGF) activates the ALA neuron, which then releases neuropeptides to promote sleep. To further understand this behavior, we established a new model of SIS using irradiation by ultraviolet C (UVC) light. While UVC irradiation requires ALA signaling and leads to a sleep state similar to that induced by heat and other stressors, it does not induce the proteostatic stress seen with heat exposure. Based on the known genotoxic effects of UVC irradiation, we tested two genes, atl-1 and cep-1, which encode proteins that act in the DNA damage response pathway. Loss-of-function mutants of atl-1 had no defect in UVC-induced SIS but a partial loss-of-function mutant of cep-1, gk138, had decreased movement quiescence following UVC irradiation. Germline ablation experiments and tissue-specific RNA interference experiments showed that cep-1 is required somatically in neurons for its effect on SIS. The cep-1(gk138) mutant suppressed body movement quiescence controlled by EGF, indicating that CEP-1 acts downstream or in parallel to ALA activation to promote quiescence in response to ultraviolet light.
Collapse
|
13
|
Davis KC, Raizen DM. A mechanism for sickness sleep: lessons from invertebrates. J Physiol 2017; 595:5415-5424. [PMID: 28028818 DOI: 10.1113/jp273009] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Accepted: 12/16/2016] [Indexed: 11/08/2022] Open
Abstract
During health, animal sleep is regulated by an internal clock and by the duration of prior wakefulness. During sickness, sleep is regulated by cytokines released from either peripheral cells or from cells within the nervous system. These cytokines regulate central nervous system neurons to induce sleep. Recent research in the invertebrates Caenorhabditis elegans and Drosophila melanogaster has led to new insights into the mechanism of sleep during sickness. Sickness is triggered by exposure to environments such as infection, heat, or ultraviolet light irradiation, all of which cause cellular stress. Epidermal growth factor is released from stressed cells and signals to activate central neuroendocrine cell(s). These neuron(s) release neuropeptides including those containing an amidated arginine(R)-phenylalanine(F) motif at their C-termini (RFamide peptides). Importantly, mechanisms regulating sickness sleep are partially distinct from those regulating healthy sleep. We will here review key findings that have elucidated the central neuroendocrine mechanism of sleep during sickness. Adaptive mechanisms employed in the control of sickness sleep may play a role in correcting cellular homeostasis after various insults. We speculate that these mechanisms may play a maladaptive role in human pathological conditions such as in the fatigue and anorexia associated with autoimmune diseases, with major depression, and with unexplained chronic fatigue.
Collapse
Affiliation(s)
- Kristen C Davis
- Department of Neurology, Centre for Sleep and Neurobiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - David M Raizen
- Department of Neurology, Centre for Sleep and Neurobiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| |
Collapse
|
14
|
Iannacone MJ, Beets I, Lopes LE, Churgin MA, Fang-Yen C, Nelson MD, Schoofs L, Raizen DM. The RFamide receptor DMSR-1 regulates stress-induced sleep in C. elegans. eLife 2017; 6. [PMID: 28094002 PMCID: PMC5241116 DOI: 10.7554/elife.19837] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 12/16/2016] [Indexed: 11/22/2022] Open
Abstract
In response to environments that cause cellular stress, animals engage in sleep behavior that facilitates recovery from the stress. In Caenorhabditis elegans, stress-induced sleep(SIS) is regulated by cytokine activation of the ALA neuron, which releases FLP-13 neuropeptides characterized by an amidated arginine-phenylalanine (RFamide) C-terminus motif. By performing an unbiased genetic screen for mutants that impair the somnogenic effects of FLP-13 neuropeptides, we identified the gene dmsr-1, which encodes a G-protein coupled receptor similar to an insect RFamide receptor. DMSR-1 is activated by FLP-13 peptides in cell culture, is required for SIS in vivo, is expressed non-synaptically in several wake-promoting neurons, and likely couples to a Gi/o heterotrimeric G-protein. Our data expand our understanding of how a single neuroendocrine cell coordinates an organism-wide behavioral response, and suggest that similar signaling principles may function in other organisms to regulate sleep during sickness. DOI:http://dx.doi.org/10.7554/eLife.19837.001 People often feel fatigued and sleepy when they are sick. Other animals also show signs of sleepiness when ill – they stop eating, move less, and are less responsive to changes in their environment. Sickness-induced sleep helps both people and other animals to recover, and many scientists believe that this type of sleep is different than nightly sleep. Studies of sickness-induced sleep have made use of a simple worm with a simple nervous system. In this worm, a single nerve cell releases chemicals that cause the worm to fall asleep in response to illness. Animals exposed to one of these chemicals, called FLP-13, fall asleep even when they are not sick. As such, scientists would like to know which cells in the nervous system FLP-13 interacts with, what receptor the cells use to recognize this chemical, and whether it turns on cells that induce sleep or turns off the cells that cause wakefulness. Now, Iannacone et al. show that FLP-13 likely causes sleep by turning down activity in the cells in the nervous system that promote wakefulness. The experiments sifted through genetic mutations to determine which ones cause the worms not to fall asleep when FLP-13 is released. This revealed that worms with a mutation that causes them to lack a receptor protein called DMSR-1 do not become sleepy in response to FLP-13. This suggests that DMSR-1 must be essential for FLP-13 to trigger sleep. About 10% of cells in the worm’s nervous system have the DMSR-1 receptor. Some of these neurons tell the worm to move forward or to forage around for food. The experiments also showed that FLP-13 is probably not the only chemical that interacts with the DMSR-1 receptor, but the identities of these other chemicals remain unknown. Additional experiments are now needed to determine if sickness-induced sleepiness in humans and other mammals is triggered by a similar mechanism. If it is, then drugs might be developed to treat people experiencing fatigue associated with sickness as well as other unexplained cases of fatigue. DOI:http://dx.doi.org/10.7554/eLife.19837.002
Collapse
Affiliation(s)
- Michael J Iannacone
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States.,Center for Sleep and Circadian Neurobiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Isabel Beets
- Department of Biology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Lindsey E Lopes
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States.,Center for Sleep and Circadian Neurobiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Matthew A Churgin
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, United States
| | - Christopher Fang-Yen
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, United States
| | - Matthew D Nelson
- Department of Biology, Saint Joseph's University, Philadelphia, United States
| | - Liliane Schoofs
- Department of Biology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - David M Raizen
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States.,Center for Sleep and Circadian Neurobiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| |
Collapse
|
15
|
Moosavi M, Hatam GR. The Sleep in Caenorhabditis elegans: What We Know Until Now. Mol Neurobiol 2017; 55:879-889. [PMID: 28078538 DOI: 10.1007/s12035-016-0362-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 12/28/2016] [Indexed: 12/12/2022]
Abstract
Sleep, as one of the most important requirements of our brain, has a mystical nature. Despite long-standing studies, the molecular mechanisms and physiological properties of sleep have not been defined well as the complexity of the mammals' brain make it difficult to investigate the mechanisms and properties of sleep. Although some features of sleep have changed during evolution, its existence in such a simple animal, Caenorhabditis elegans, not only signifies the importance of sleep in even simple animals, but also allows the scientist to assess the core mechanism and biological events in an uncomplicated organism. This article reviews the information which exists about the characteristics of sleep in C. elegans, its circadian rhythm, the neurons and neurotransmitters responsible for each state, and the signaling molecules involved. Although much still remains to be resolved about the sleep of C. elegans, the available knowledge helps the scientists to recognize the properties better of this mysterious function of the brain.
Collapse
Affiliation(s)
- Maryam Moosavi
- Nanomedicine and Nanobiology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.,Department of Physiology, Medical School, Shiraz University of Medical sciences, Shiraz, Iran
| | - Gholam Reza Hatam
- Basic Sciences in Infectious Diseases Research Center, Shiraz University of Medical Sciences, Shiraz, Iran. .,Department of Parasitology and Mycology, Shiraz University of Medical Sciences, Shiraz, Iran.
| |
Collapse
|
16
|
Krishnan HC, Gandour CE, Ramos JL, Wrinkle MC, Sanchez-Pacheco JJ, Lyons LC. Acute Sleep Deprivation Blocks Short- and Long-Term Operant Memory in Aplysia. Sleep 2016; 39:2161-2171. [PMID: 27748243 DOI: 10.5665/sleep.6320] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 08/08/2016] [Indexed: 01/11/2023] Open
Abstract
STUDY OBJECTIVES Insufficient sleep in individuals appears increasingly common due to the demands of modern work schedules and technology use. Consequently, there is a growing need to understand the interactions between sleep deprivation and memory. The current study determined the effects of acute sleep deprivation on short and long-term associative memory using the marine mollusk Aplysia californica, a relatively simple model system well known for studies of learning and memory. METHODS Aplysia were sleep deprived for 9 hours using context changes and tactile stimulation either prior to or after training for the operant learning paradigm, learning that food is inedible (LFI). The effects of sleep deprivation on short-term (STM) and long-term memory (LTM) were assessed. RESULTS Acute sleep deprivation prior to LFI training impaired the induction of STM and LTM with persistent effects lasting at least 24 h. Sleep deprivation immediately after training blocked the consolidation of LTM. However, sleep deprivation following the period of molecular consolidation did not affect memory recall. Memory impairments were independent of handling-induced stress, as daytime handled control animals demonstrated no memory deficits. Additional training immediately after sleep deprivation failed to rescue the induction of memory, but additional training alleviated the persistent impairment in memory induction when training occurred 24 h following sleep deprivation. CONCLUSIONS Acute sleep deprivation inhibited the induction and consolidation, but not the recall of memory. These behavioral studies establish Aplysia as an effective model system for studying the interactions between sleep and memory formation.
Collapse
Affiliation(s)
- Harini C Krishnan
- Department of Biological Science, Florida State University, Tallahassee, FL.,Program in Neuroscience, Florida State University, Tallahassee, FL
| | | | - Joshua L Ramos
- Department of Biological Science, Florida State University, Tallahassee, FL
| | - Mariah C Wrinkle
- Department of Biological Science, Florida State University, Tallahassee, FL
| | | | - Lisa C Lyons
- Department of Biological Science, Florida State University, Tallahassee, FL.,Program in Neuroscience, Florida State University, Tallahassee, FL
| |
Collapse
|