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Chowdhury B, Shafer OT. Drosophila sleep homeostasis in sickness and in health. Sleep 2024; 47:zsae128. [PMID: 38899406 DOI: 10.1093/sleep/zsae128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Indexed: 06/21/2024] Open
Affiliation(s)
- Budhaditya Chowdhury
- The Advanced Science Research Center, The City University of New York; The Graduate Center at the City University of New York, New York, NY, USA
| | - Orie T Shafer
- The Advanced Science Research Center, The City University of New York; The Graduate Center at the City University of New York, New York, NY, USA
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2
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Chaturvedi R, Emery P. Fly into tranquility: GABA's role in Drosophila sleep. CURRENT OPINION IN INSECT SCIENCE 2024; 64:101219. [PMID: 38848811 PMCID: PMC11290982 DOI: 10.1016/j.cois.2024.101219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Revised: 05/28/2024] [Accepted: 05/31/2024] [Indexed: 06/09/2024]
Abstract
Sleep is conserved across the animal kingdom, and Drosophila melanogaster is a prime model to understand its intricate circadian and homeostatic control. GABA (gamma-aminobutyric acid), the brain's main inhibitory neurotransmitter, plays a central role in sleep. This review delves into GABA's complex mechanisms of actions within Drosophila's sleep-regulating neural networks. We discuss how GABA promotes sleep, both by inhibiting circadian arousal neurons and by being a key neurotransmitter in sleep homeostatic circuits. GABA's impact on sleep is modulated by glia through astrocytic GABA recapture and metabolism. Interestingly, GABA can be coexpressed with other neurotransmitters in sleep-regulating neurons, which likely contributes to context-based sleep plasticity.
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Affiliation(s)
- Ratna Chaturvedi
- Department of Neurobiology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Patrick Emery
- Department of Neurobiology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA.
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3
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Inami S, Koh K. Sleep induced by mechanosensory stimulation provides cognitive and health benefits in Drosophila. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.10.602891. [PMID: 39026689 PMCID: PMC11257551 DOI: 10.1101/2024.07.10.602891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Study Objectives Sleep is a complex phenomenon regulated by various factors, including sensory input. Anecdotal observations have suggested that gentle rocking helps babies fall asleep, and experimental studies have verified that rocking promotes sleep in both humans and mice. Recent studies have expanded this understanding, demonstrating that gentle vibration also induces sleep in Drosophila. Natural sleep serves multiple functions, including learning and memory, synaptic downscaling, and clearance of harmful substances associated with neurodegenerative diseases. Here, we investigated whether vibration-induced sleep provides similar cognitive and health benefits in Drosophila. Methods We administered gentle vibration to flies that slept very little due to a forced activation of wake-promoting neurons and investigated how the vibration influenced learning and memory in the courtship conditioning paradigm. Additionally, we examined the effects of VIS on synaptic downscaling by counting synapse numbers of select neurons. Finally, we determined whether vibration could induce sleep in Drosophila models of Alzheimer's disease (AD) and promote the clearance of Amyloid b (Ab) and Tubulin Associated Unit (TAU). Results Vibration-induced sleep enhanced performance in a courtship conditioning paradigm and reduced the number of synapses in select neurons. Moreover, vibration improved sleep in Drosophila models of AD, promoting the clearance of Ab and TAU. Conclusions Mechanosensory stimulation offers a promising non-invasive avenue for enhancing sleep, potentially providing associated cognitive and health benefits.
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Affiliation(s)
- Sho Inami
- Department of Neuroscience and the Farber Institute for Neurosciences, Thomas Jefferson University
| | - Kyunghee Koh
- Department of Neuroscience and the Farber Institute for Neurosciences, Thomas Jefferson University
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4
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Gallman K, Rastogi A, North O, O'Gorman M, Hutton P, Lloyd E, Warren W, Kowalko JE, Duboue ER, Rohner N, Keene AC. Postprandial sleep in short-sleeping Mexican cavefish. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.03.602003. [PMID: 39005273 PMCID: PMC11244998 DOI: 10.1101/2024.07.03.602003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Interaction between sleep and feeding behaviors are critical for adaptive fitness. Diverse species suppress sleep when food is scarce to increase the time spent foraging. Post-prandial sleep, an increase in sleep time following a feeding event, has been documented in vertebrate and invertebrate animals. While interactions between sleep and feeding appear to be highly conserved, the evolution of postprandial sleep in response to changes in food availability remains poorly understood. Multiple populations of the Mexican cavefish, Astyanax mexicanus, have independently evolved sleep loss and increased food consumption compared to surface-dwelling fish of the same species, providing the opportunity to investigate the evolution of interactions between sleep and feeding. Here, we investigate effects of feeding on sleep in larval and adult surface fish, and two parallelly evolved cave populations of A. mexicanus. Larval surface and cave populations of A. mexicanus increase sleep immediately following a meal, providing the first evidence of postprandial sleep in a fish model. The amount of sleep was not correlated to meal size and occurred independently of feeding time. In contrast to larvae, postprandial sleep was not detected in adult surface or cavefish, that can survive for months without food. Together, these findings reveal that postprandial sleep is present in multiple short-sleeping populations of cavefish, suggesting sleep-feeding interactions are retained despite the evolution of sleep loss. These findings raise the possibility that postprandial sleep is critical for energy conservation and survival in larvae that are highly sensitive to food deprivation.
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Affiliation(s)
- Kathryn Gallman
- Department of Biology, Texas A&M University, College Station, TX 77840
| | - Aakriti Rastogi
- Department of Biology, Texas A&M University, College Station, TX 77840
| | - Owen North
- Department of Biology, Texas A&M University, College Station, TX 77840
| | - Morgan O'Gorman
- Department of Biology, Texas A&M University, College Station, TX 77840
| | - Pierce Hutton
- Department of Biology, Texas A&M University, College Station, TX 77840
| | - Evan Lloyd
- Department of Biology, Texas A&M University, College Station, TX 77840
| | - Wes Warren
- Department of Genomics, University of Missouri, Columbia, MO 65201
| | - Johanna E Kowalko
- Department of Biological Sciences, Lehigh University, Bethlehem, PA 18015
| | | | - Nicolas Rohner
- Stowers Institute for Medical Research, Kansas City, MO 64110
| | - Alex C Keene
- Department of Biology, Texas A&M University, College Station, TX 77840
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5
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Lesku JA, Libourel PA, Kelly ML, Hemmi JM, Kerr CC, Collin SP, Radford CA. An electrophysiological correlate of sleep in a shark. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2024. [PMID: 38957102 DOI: 10.1002/jez.2846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 06/11/2024] [Accepted: 06/13/2024] [Indexed: 07/04/2024]
Abstract
Sleep is a prominent physiological state observed across the animal kingdom. Yet, for some animals, our ability to identify sleep can be masked by behaviors otherwise associated with being awake, such as for some sharks that must swim continuously to push oxygenated seawater over their gills to breathe. We know that sleep in buccal pumping sharks with clear rest/activity cycles, such as draughtsboard sharks (Cephaloscyllium isabellum, Bonnaterre, 1788), manifests as a behavioral shutdown, postural relaxation, reduced responsiveness, and a lowered metabolic rate. However, these features of sleep do not lend themselves well to animals that swim nonstop. In addition to video and accelerometry recordings, we tried to explore the electrophysiological correlates of sleep in draughtsboard sharks using electroencephalography (EEG), electromyography, and electrooculography, while monitoring brain temperature. The seven channels of EEG activity had a surprising level of (apparent) instability when animals were swimming, but also when sleeping. The amount of stable EEG signals was too low for replication within- and across individuals. Eye movements were not measurable, owing to instability of the reference electrode. Based on an established behavioral characterization of sleep in draughtsboard sharks, we offer the original finding that muscle tone was strongest during active wakefulness, lower in quietly awake sharks, and lowest in sleeping sharks. We also offer several critical suggestions on how to improve techniques for characterizing sleep electrophysiology in future studies on elasmobranchs, particularly for those that swim continuously. Ultimately, these approaches will provide important insights into the evolutionary confluence of behaviors typically associated with wakefulness and sleep.
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Affiliation(s)
- John A Lesku
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Victoria, Australia
| | - Paul-Antoine Libourel
- Center for Functional and Evolutionary Ecology, MAD Team, Montpellier, France
- Neuroscience Research Center of Lyon, Sleep Team, Bron, France
| | - Michael L Kelly
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Victoria, Australia
- Australian Centre for Disease Preparedness, Commonwealth Scientific and Industrial Research Organisation, Geelong, Victoria, Australia
| | - Jan M Hemmi
- School of Biological Sciences, The University of Western Australia, Perth, Western Australia, Australia
- Oceans Institute, The University of Western Australia, Perth, Western Australia, Australia
| | - Caroline C Kerr
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Victoria, Australia
| | - Shaun P Collin
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Victoria, Australia
- Oceans Institute, The University of Western Australia, Perth, Western Australia, Australia
| | - Craig A Radford
- Institute of Marine Science, Leigh Marine Laboratory, The University of Auckland, Auckland, New Zealand
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6
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Park SJ, Murphy KR, Ja WW. Energy Deficit is a Key Driver of Sleep Homeostasis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.30.596666. [PMID: 38979352 PMCID: PMC11230206 DOI: 10.1101/2024.05.30.596666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Sleep and feeding are vital homeostatic behaviors, and disruptions in either can result in substantial metabolic consequences. Distinct neuronal manipulations in Drosophila can dissociate sleep loss from subsequent homeostatic rebound, offering an optimal platform to examine the precise interplay between these fundamental behaviors. Here, we investigate concomitant changes in sleep and food intake in individual animals, as well as respiratory metabolic expenditure, that accompany behavioral and genetic manipulations that induce sleep loss in Drosophila melanogaster. We find that sleep disruptions resulting in energy deficit through increased metabolic expenditure and manifested as increased food intake were consistently followed by rebound sleep. In contrast, "soft" sleep loss, which does not induce rebound sleep, is not accompanied by increased metabolism and food intake. Our results demonstrate that homeostatic sleep rebound is linked to energy deficit accrued during sleep loss. Collectively, these findings support the notion that sleep functions to conserve energy and highlight the need to examine the effects of metabolic therapeutics on sleep.
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Affiliation(s)
- Scarlet J Park
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, FL 33458, USA
- Skaggs Graduate School of Chemical and Biological Sciences, Jupiter, FL 33458, USA
- Current affiliation: Nova Southeastern University, Palm Beach Gardens, FL 33410, USA
| | - Keith R Murphy
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, FL 33458, USA
- Integrative Biology and Neuroscience Program, Florida Atlantic University, Jupiter FL 33458, USA
- Current affiliation: Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, USA
| | - William W Ja
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, FL 33458, USA
- Skaggs Graduate School of Chemical and Biological Sciences, Jupiter, FL 33458, USA
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7
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Marshall JP, Marinko E, To A, Morejon JL, Joshi R, Shea J, Gibbs AG, Meiselman MR. Circadian regulation of locomotion, respiration, and arousability in adult blacklegged ticks (Ixodes scapularis). Sci Rep 2024; 14:14804. [PMID: 38926516 PMCID: PMC11208436 DOI: 10.1038/s41598-024-65498-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Accepted: 06/20/2024] [Indexed: 06/28/2024] Open
Abstract
The blacklegged tick, Ixodes scapularis, is an ectoparasitic arachnid and vector for infectious diseases, including Lyme borreliosis. Here, we investigate the diurnal activity and respiration of wild-caught and lab-reared adult ticks with long-term video recording, multi-animal tracking and high-resolution respirometry. We find male and female ticks are in a more active, more arousable state during circadian night. We find respiration is augmented by light, with dark onset triggering more frequent bouts of discontinuous gas exchange and a higher overall volume of CO2 respired. Observed inactivity during the day meets the criteria of sleep: homeostatic in nature, rapidly reversible, a characteristic pose, and reduced arousal threshold. Our findings indicate that blacklegged ticks are in a distinct, heightened state of activity and arousability during night and in dark, suggesting this period may carry higher risk for tick bites and subsequent contraction of tick-borne diseases.
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Affiliation(s)
- Jack P Marshall
- School of Life Sciences, University of Nevada-Las Vegas, Las Vegas, NV, 89154, USA
| | - Emily Marinko
- School of Life Sciences, University of Nevada-Las Vegas, Las Vegas, NV, 89154, USA
| | - Amber To
- School of Life Sciences, University of Nevada-Las Vegas, Las Vegas, NV, 89154, USA
| | - Jilian L Morejon
- School of Life Sciences, University of Nevada-Las Vegas, Las Vegas, NV, 89154, USA
| | - Ritika Joshi
- School of Life Sciences, University of Nevada-Las Vegas, Las Vegas, NV, 89154, USA
| | - Jamien Shea
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, 14853, USA
| | - Allen G Gibbs
- School of Life Sciences, University of Nevada-Las Vegas, Las Vegas, NV, 89154, USA
| | - Matthew R Meiselman
- School of Life Sciences, University of Nevada-Las Vegas, Las Vegas, NV, 89154, USA.
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8
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Yano J, Nave C, Larratt K, Honey P, Roberts M, Jingco C, Fung ML, Trotter D, He X, Elezi G, Whitelegge JP, Wasserman S, Donlea JM. Elevated sleep quota in a stress-resilient Drosophila species. Curr Biol 2024; 34:2487-2501.e3. [PMID: 38772361 PMCID: PMC11163955 DOI: 10.1016/j.cub.2024.04.060] [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: 09/26/2023] [Revised: 01/09/2024] [Accepted: 04/25/2024] [Indexed: 05/23/2024]
Abstract
Sleep is broadly conserved across the animal kingdom but can vary widely between species. It is currently unclear which selective pressures and regulatory mechanisms influence differences in sleep between species. The fruit fly Drosophila melanogaster has become a successful model system for examining sleep regulation and function, but little is known about the sleep patterns in many related fly species. Here, we find that fly species with adaptations to extreme desert environments, including D. mojavensis, exhibit strong increases in baseline sleep compared with D. melanogaster. Long-sleeping D. mojavensis show intact homeostasis, indicating that desert flies carry an elevated drive for sleep. In addition, D. mojavensis exhibit altered abundance or distribution of several sleep/wake-related neuromodulators and neuropeptides that are consistent with their reduced locomotor activity and increased sleep. Finally, we find that in a nutrient-deprived environment, the sleep patterns of individual D. mojavensis are strongly correlated with their survival time and that disrupting sleep via constant light stimulation renders D. mojavensis more sensitive to starvation. Our results demonstrate that D. mojavensis is a novel model for studying organisms with high sleep drive and for exploring sleep strategies that provide resilience in extreme environments.
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Affiliation(s)
- Jessica Yano
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Molecular, Cellular & Integrative Physiology Interdepartmental PhD Program, UCLA, Los Angeles, CA 90095, USA
| | - Ceazar Nave
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Katherine Larratt
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Phia Honey
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Department of Neuroscience, Wellesley College, Wellesley, MA 02481, USA
| | - Makayla Roberts
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Cassandra Jingco
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Melanie L Fung
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Damion Trotter
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Molecular, Cellular & Integrative Physiology Interdepartmental PhD Program, UCLA, Los Angeles, CA 90095, USA
| | - Xin He
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Gazmend Elezi
- Pasarow Mass Spectrometry Laboratory, Jane & Terry Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Cotsen Institute of Archaeology, UCLA, Los Angeles, CA 90095, USA
| | - Julian P Whitelegge
- Pasarow Mass Spectrometry Laboratory, Jane & Terry Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Sara Wasserman
- Department of Neuroscience, Wellesley College, Wellesley, MA 02481, USA
| | - Jeffrey M Donlea
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA.
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9
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Omond SET, Barker RG, Sanislav O, Fisher PR, Annesley SJ, Lesku JA. Oxygen consumption rate of flatworms under the influence of wake- and sleep-promoting neurotransmitters. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2024. [PMID: 38801005 DOI: 10.1002/jez.2828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2024] [Revised: 05/09/2024] [Accepted: 05/09/2024] [Indexed: 05/29/2024]
Abstract
Flatworms are among the best studied animal models for regeneration; however, they also represent an emerging opportunity to investigate other biological processes as well. For instance, flatworms are nocturnal and sleep during the day, a state that is regulated by sleep/wake history and the action of the sleep-promoting neurotransmitter gamma-aminobutyric acid (or GABA). Sleep is widespread across the animal kingdom, where it serves many nonexclusive functions. Notably, sleep saves energy by reducing metabolic rate and by not doing something more energetically taxing. Whether the conservation of energy is apparent in sleeping flatworms is unclear. We measured the oxygen consumption rate (OCR) of flatworms dosed with either (1) GABA (n = 29) which makes flatworms inactive or (2) dopamine (n = 20) which stimulates flatworms to move, or (3) day and night neurotransmitter-free controls (n = 28 and 27, respectively). While OCR did not differ between the day and night, flatworms treated with GABA used less oxygen than those treated with dopamine, and less than the day-time control. Thus, GABA affected flatworm physiology, ostensibly by enforcing energy-conserving sleep. Evidence that dopamine increased metabolism was less strong. This work broadens our understanding of flatworm physiology and expands the phylogenetic applicability of energy conservation as a function of sleep.
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Affiliation(s)
- Shauni E T Omond
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Australia
| | - Robert G Barker
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Australia
| | - Oana Sanislav
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Australia
| | - Paul R Fisher
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Australia
| | - Sarah J Annesley
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Australia
| | - John A Lesku
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Australia
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10
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Draper IR, Roberts MA, Gailloud M, Jackson FR. Drosophila noktochor regulates night sleep via a local mushroom body circuit. iScience 2024; 27:109106. [PMID: 38380256 PMCID: PMC10877950 DOI: 10.1016/j.isci.2024.109106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 11/22/2023] [Accepted: 01/31/2024] [Indexed: 02/22/2024] Open
Abstract
We show that a sleep-regulating, Ig-domain protein (NKT) is secreted from Drosophila mushroom body (MB) α'/β' neurons to act locally on other MB cell types. Pan-neuronal or broad MB expression of membrane-tethered NKT (tNkt) protein reduced sleep, like that of an NKT null mutant, suggesting blockade of a receptor mediating endogenous NKT action. In contrast, expression in neurons requiring NKT (the MB α'/β' cells), or non-MB sleep-regulating centers, did not reduce night sleep, indicating the presence of a local MB sleep-regulating circuit consisting of communicating neural subtypes. We suggest that the leucocyte-antigen-related like (Lar) transmembrane receptor may mediate NKT action. Knockdown or overexpression of Lar in the MB increased or decreased sleep, respectively, indicating the receptor promotes wakefulness. Surprisingly, selective expression of tNkt or knockdown of Lar in MB wake-promoting cells increased rather than decreased sleep, suggesting that NKT acts on wake- as well as sleep-promoting cell types to regulate sleep.
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Affiliation(s)
- Isabelle R. Draper
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
- Department of Medicine, Molecular Cardiology Research Institute, Tufts Medical Center, 800 Washington Street, Boston, MA 02111, USA
| | - Mary A. Roberts
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Matthew Gailloud
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - F. Rob Jackson
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
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11
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Abhilash L, Shafer OT. A two-process model of Drosophila sleep reveals an inter-dependence between circadian clock speed and the rate of sleep pressure decay. Sleep 2024; 47:zsad277. [PMID: 37930351 PMCID: PMC11275470 DOI: 10.1093/sleep/zsad277] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 10/18/2023] [Indexed: 11/07/2023] Open
Abstract
Sleep is controlled by two processes-a circadian clock that regulates its timing and a homeostat that regulates the drive to sleep. Drosophila has been an insightful model for understanding both processes. For four decades, Borbély and Daan's two-process model has provided a powerful framework for understanding sleep regulation. However, the field of fly sleep has not employed such a model as a framework for the investigation of sleep. To this end, we have adapted the two-process model to the fly and established its utility by showing that it can provide empirically testable predictions regarding the circadian and homeostatic control of fly sleep. We show that the ultradian rhythms previously reported for loss-of-function clock mutants in the fly are robustly detectable and a predictable consequence of a functional sleep homeostat in the absence of a functioning circadian system. We find that a model in which the circadian clock speed and homeostatic rates act without influencing each other provides imprecise predictions regarding how clock speed influences the strength of sleep rhythms and the amount of daily sleep. We also find that quantitatively good fits between empirical values and model predictions were achieved only when clock speeds were positively correlated with rates of decay of sleep pressure. Our results indicate that longer sleep bouts better reflect the homeostatic process than the current definition of sleep as any inactivity lasting 5 minutes or more. This two-process model represents a powerful framework for work on the molecular and physiological regulation of fly sleep.
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Affiliation(s)
- Lakshman Abhilash
- The Advanced Science Research Center, The City University of New York, New York, NY, USA
| | - Orie Thomas Shafer
- The Advanced Science Research Center, The City University of New York, New York, NY, USA
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12
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Brown EB, Zhang J, Lloyd E, Lanzon E, Botero V, Tomchik S, Keene AC. Neurofibromin 1 mediates sleep depth in Drosophila. PLoS Genet 2023; 19:e1011049. [PMID: 38091360 PMCID: PMC10763969 DOI: 10.1371/journal.pgen.1011049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 01/03/2024] [Accepted: 11/03/2023] [Indexed: 01/04/2024] Open
Abstract
Neural regulation of sleep and metabolic homeostasis are critical in many aspects of human health. Despite extensive epidemiological evidence linking sleep dysregulation with obesity, diabetes, and metabolic syndrome, little is known about the neural and molecular basis for the integration of sleep and metabolic function. The RAS GTPase-activating gene Neurofibromin (Nf1) has been implicated in the regulation of sleep and metabolic rate, raising the possibility that it serves to integrate these processes, but the effects on sleep consolidation and physiology remain poorly understood. A key hallmark of sleep depth in mammals and flies is a reduction in metabolic rate during sleep. Here, we examine multiple measures of sleep quality to determine the effects of Nf1 on sleep-dependent changes in arousal threshold and metabolic rate. Flies lacking Nf1 fail to suppress metabolic rate during sleep, raising the possibility that loss of Nf1 prevents flies from integrating sleep and metabolic state. Sleep of Nf1 mutant flies is fragmented with a reduced arousal threshold in Nf1 mutants, suggesting Nf1 flies fail to enter deep sleep. The effects of Nf1 on sleep can be localized to a subset of neurons expressing the GABAA receptor Rdl. Sleep loss has been associated with changes in gut homeostasis in flies and mammals. Selective knockdown of Nf1 in Rdl-expressing neurons within the nervous system increases gut permeability and reactive oxygen species (ROS) in the gut, raising the possibility that loss of sleep quality contributes to gut dysregulation. Together, these findings suggest Nf1 acts in GABA-sensitive neurons to modulate sleep depth in Drosophila.
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Affiliation(s)
- Elizabeth B. Brown
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
- Department of Biological Sciences, Florida State University, Tallahassee, Florida, United States of America
| | - Jiwei Zhang
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
| | - Evan Lloyd
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
| | - Elizabeth Lanzon
- Jupiter Life Science Initiative, Florida Atlantic University, Jupiter, Florida, United States of America
| | - Valentina Botero
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa, United States of America
| | - Seth Tomchik
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa, United States of America
| | - Alex C. Keene
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
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13
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Anthoney N, Tainton-Heap L, Luong H, Notaras E, Kewin AB, Zhao Q, Perry T, Batterham P, Shaw PJ, van Swinderen B. Experimentally induced active and quiet sleep engage non-overlapping transcriptional programs in Drosophila. eLife 2023; 12:RP88198. [PMID: 37910019 PMCID: PMC10619980 DOI: 10.7554/elife.88198] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023] Open
Abstract
Sleep in mammals can be broadly classified into two different physiological categories: rapid eye movement (REM) sleep and slow-wave sleep (SWS), and accordingly REM and SWS are thought to achieve a different set of functions. The fruit fly Drosophila melanogaster is increasingly being used as a model to understand sleep functions, although it remains unclear if the fly brain also engages in different kinds of sleep as well. Here, we compare two commonly used approaches for studying sleep experimentally in Drosophila: optogenetic activation of sleep-promoting neurons and provision of a sleep-promoting drug, gaboxadol. We find that these different sleep-induction methods have similar effects on increasing sleep duration, but divergent effects on brain activity. Transcriptomic analysis reveals that drug-induced deep sleep ('quiet' sleep) mostly downregulates metabolism genes, whereas optogenetic 'active' sleep upregulates a wide range of genes relevant to normal waking functions. This suggests that optogenetics and pharmacological induction of sleep in Drosophila promote different features of sleep, which engage different sets of genes to achieve their respective functions.
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Affiliation(s)
- Niki Anthoney
- Queensland Brain Institute, The University of QueenslandBrisbaneAustralia
| | - Lucy Tainton-Heap
- Queensland Brain Institute, The University of QueenslandBrisbaneAustralia
| | - Hang Luong
- School of BioSciences, The University of MelbourneMelbourneAustralia
| | - Eleni Notaras
- Queensland Brain Institute, The University of QueenslandBrisbaneAustralia
| | - Amber B Kewin
- Queensland Brain Institute, The University of QueenslandBrisbaneAustralia
| | - Qiongyi Zhao
- Queensland Brain Institute, The University of QueenslandBrisbaneAustralia
| | - Trent Perry
- School of BioSciences, The University of MelbourneMelbourneAustralia
| | - Philip Batterham
- School of BioSciences, The University of MelbourneMelbourneAustralia
| | - Paul J Shaw
- Department of Neuroscience, School of Medicine, Washington University in St. LouisSt LouisUnited States
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14
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Chowdhury B, Abhilash L, Ortega A, Liu S, Shafer O. Homeostatic control of deep sleep and molecular correlates of sleep pressure in Drosophila. eLife 2023; 12:e91355. [PMID: 37906092 PMCID: PMC10642965 DOI: 10.7554/elife.91355] [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: 07/25/2023] [Accepted: 10/22/2023] [Indexed: 11/02/2023] Open
Abstract
Homeostatic control of sleep is typically addressed through mechanical stimulation-induced forced wakefulness and the measurement of subsequent increases in sleep. A major confound attends this approach: biological responses to deprivation may reflect a direct response to the mechanical insult rather than to the loss of sleep. Similar confounds accompany all forms of sleep deprivation and represent a major challenge to the field. Here, we describe a new paradigm for sleep deprivation in Drosophila that fully accounts for sleep-independent effects. Our results reveal that deep sleep states are the primary target of homeostatic control and establish the presence of multi-cycle sleep rebound following deprivation. Furthermore, we establish that specific deprivation of deep sleep states results in state-specific homeostatic rebound. Finally, by accounting for the molecular effects of mechanical stimulation during deprivation experiments, we show that serotonin levels track sleep pressure in the fly's central brain. Our results illustrate the critical need to control for sleep-independent effects of deprivation when examining the molecular correlates of sleep pressure and call for a critical reassessment of work that has not accounted for such non-specific effects.
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Affiliation(s)
- Budhaditya Chowdhury
- The Advanced Science Research Center, The City University of New York; The Graduate Center at the City University of New YorkNew YorkUnited States
| | - Lakshman Abhilash
- The Advanced Science Research Center, The City University of New York; The Graduate Center at the City University of New YorkNew YorkUnited States
| | - Antonio Ortega
- VIB-KU Leuven Center for Brain & Disease ResearchLeuvenBelgium
| | - Sha Liu
- VIB-KU Leuven Center for Brain & Disease ResearchLeuvenBelgium
| | - Orie Shafer
- The Advanced Science Research Center, The City University of New York; The Graduate Center at the City University of New YorkNew YorkUnited States
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15
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Anthoney N, Tainton-Heap LA, Luong H, Notaras E, Kewin AB, Zhao Q, Perry T, Batterham P, Shaw PJ, van Swinderen B. Experimentally induced active and quiet sleep engage non-overlapping transcriptional programs in Drosophila. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.03.535331. [PMID: 37066182 PMCID: PMC10103959 DOI: 10.1101/2023.04.03.535331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Sleep in mammals can be broadly classified into two different physiological categories: rapid eye movement (REM) sleep and slow wave sleep (SWS), and accordingly REM and SWS are thought to achieve a different set of functions. The fruit fly Drosophila melanogaster is increasingly being used as a model to understand sleep functions, although it remains unclear if the fly brain also engages in different kinds of sleep as well. Here, we compare two commonly used approaches for studying sleep experimentally in Drosophila: optogenetic activation of sleep-promoting neurons and provision of a sleep-promoting drug, Gaboxadol. We find that these different sleep-induction methods have similar effects on increasing sleep duration, but divergent effects on brain activity. Transcriptomic analysis reveals that drug-induced deep sleep ('quiet' sleep) mostly downregulates metabolism genes, whereas optogenetic 'active' sleep upregulates a wide range of genes relevant to normal waking functions. This suggests that optogenetics and pharmacological induction of sleep in Drosophila promote different features of sleep, which engage different sets of genes to achieve their respective functions.
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Affiliation(s)
- Niki Anthoney
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072 Australia
| | | | - Hang Luong
- School of BioSciences, The University of Melbourne, Melbourne, VIC 3052 Australia
| | - Eleni Notaras
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072 Australia
| | - Amber B. Kewin
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072 Australia
| | - Qiongyi Zhao
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072 Australia
| | - Trent Perry
- School of BioSciences, The University of Melbourne, Melbourne, VIC 3052 Australia
| | - Philip Batterham
- School of BioSciences, The University of Melbourne, Melbourne, VIC 3052 Australia
| | - Paul J. Shaw
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO USA
| | - Bruno van Swinderen
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072 Australia
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16
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Hartmann C, Kempf A. Mitochondrial control of sleep. Curr Opin Neurobiol 2023; 81:102733. [PMID: 37390796 DOI: 10.1016/j.conb.2023.102733] [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: 02/26/2023] [Revised: 05/03/2023] [Accepted: 05/03/2023] [Indexed: 07/02/2023]
Abstract
The function of sleep remains one of biology's biggest mysteries. A solution to this problem is likely to come from a better understanding of sleep homeostasis, and in particular of the cellular and molecular processes that sense sleep need and settle sleep debt. Here, we highlight recent work in the fruit fly showing that changes in the mitochondrial redox state of sleep-promoting neurons lie at the heart of a homeostatic sleep-regulatory mechanism. Since the function of homeostatically controlled behaviours is often linked to the regulated variable itself, these findings corroborate with the hypothesis that sleep serves a metabolic function.
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Affiliation(s)
- Celina Hartmann
- Biozentrum, University of Basel, CH-4056, Basel, Switzerland
| | - Anissa Kempf
- Biozentrum, University of Basel, CH-4056, Basel, Switzerland.
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17
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Goda T, Umezaki Y, Hamada FN. Molecular and Neural Mechanisms of Temperature Preference Rhythm in Drosophila melanogaster. J Biol Rhythms 2023; 38:326-340. [PMID: 37222551 PMCID: PMC10330063 DOI: 10.1177/07487304231171624] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Temperature influences animal physiology and behavior. Animals must set an appropriate body temperature to maintain homeostasis and maximize survival. Mammals set their body temperatures using metabolic and behavioral strategies. The daily fluctuation in body temperature is called the body temperature rhythm (BTR). For example, human body temperature increases during wakefulness and decreases during sleep. BTR is controlled by the circadian clock, is closely linked with metabolism and sleep, and entrains peripheral clocks located in the liver and lungs. However, the underlying mechanisms of BTR are largely unclear. In contrast to mammals, small ectotherms, such as Drosophila, control their body temperatures by choosing appropriate environmental temperatures. The preferred temperature of Drosophila increases during the day and decreases at night; this pattern is referred to as the temperature preference rhythm (TPR). As flies are small ectotherms, their body temperature is close to that of the surrounding environment. Thus, Drosophila TPR produces BTR, which exhibits a pattern similar to that of human BTR. In this review, we summarize the regulatory mechanisms of TPR, including recent studies that describe neuronal circuits relaying ambient temperature information to dorsal neurons (DNs). The neuropeptide diuretic hormone 31 (DH31) and its receptor (DH31R) regulate TPR, and a mammalian homolog of DH31R, the calcitonin receptor (CALCR), also plays an important role in mouse BTR regulation. In addition, both fly TPR and mammalian BTR are separately regulated from another clock output, locomotor activity rhythms. These findings suggest that the fundamental mechanisms of BTR regulation may be conserved between mammals and flies. Furthermore, we discuss the relationships between TPR and other physiological functions, such as sleep. The dissection of the regulatory mechanisms of Drosophila TPR could facilitate an understanding of mammalian BTR and the interaction between BTR and sleep regulation.
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Affiliation(s)
- Tadahiro Goda
- Department of Neurobiology, Physiology & Behavior, University of California, Davis, Davis, California
| | - Yujiro Umezaki
- Department of Neurobiology, Physiology & Behavior, University of California, Davis, Davis, California
| | - Fumika N. Hamada
- Department of Neurobiology, Physiology & Behavior, University of California, Davis, Davis, California
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18
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Bhattacharya D, Górska-Andrzejak J, Abaquita TAL, Pyza E. Effects of adenosine receptor overexpression and silencing in neurons and glial cells on lifespan, fitness, and sleep of Drosophila melanogaster. Exp Brain Res 2023:10.1007/s00221-023-06649-y. [PMID: 37335362 DOI: 10.1007/s00221-023-06649-y] [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: 10/03/2022] [Accepted: 05/28/2023] [Indexed: 06/21/2023]
Abstract
A single adenosine receptor gene (dAdoR) has been detected in Drosophila melanogaster. However, its function in different cell types of the nervous system is mostly unknown. Therefore, we overexpressed or silenced the dAdoR gene in eye photoreceptors, all neurons, or glial cells and examined the fitness of flies, the amount and daily pattern of sleep, and the influence of dAdoR silencing on Bruchpilot (BRP) presynaptic protein. Furthermore, we examined the dAdoR and brp gene expression in young and old flies. We found that a higher level of dAdoR in the retina photoreceptors, all neurons, and glial cells negatively influenced the survival rate and lifespan of male and female Drosophila in a cell-dependent manner and to a different extent depending on the age of the flies. In old flies, expression of both dAdoR and brp was higher than in young ones. An excess of dAdoR in neurons improved climbing in older individuals. It also influenced sleep by lengthening nighttime sleep and siesta. In turn, silencing of dAdoR decreased the lifespan of flies, although it increased the survival rate of young flies. It hindered the climbing of older males and females, but did not change sleep. Silencing also affected the daily pattern of BRP abundance, especially when dAdoR expression was decreased in glial cells. The obtained results indicate the role of adenosine and dAdoR in the regulation of fitness in flies that is based on communication between neurons and glial cells, and the effect of glial cells on synapses.
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Affiliation(s)
| | | | | | - Elżbieta Pyza
- Department of Cell Biology and Imaging, Jagellonian University, Kraków, Poland.
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19
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Yano J, Nave C, Larratt K, Honey P, Jingco C, Roberts M, Trotter D, He X, Elezi G, Whitelegge JP, Wasserman S, Donlea JM. Elevated sleep need in a stress-resilient Drosophila species. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.27.542279. [PMID: 37292829 PMCID: PMC10245952 DOI: 10.1101/2023.05.27.542279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Sleep is broadly conserved across the animal kingdom, but can vary widely between species. It is currently unclear which types of selective pressures and sleep regulatory mechanisms influence differences in sleep between species. The fruit fly Drosophila melanogaster has become a successful model system for examining sleep regulation and function, but little is known about the sleep patterns and need for sleep in many related fly species. Here, we find that Drosophila mojavensis, a fly species that has adapted to extreme desert environments, exhibits strong increases in sleep compared to D. melanogaster. Long-sleeping D. mojavensis show intact sleep homeostasis, indicating that these flies carry an elevated need for sleep. In addition, D. mojavensis exhibit altered abundance or distribution of several sleep/wake related neuromodulators and neuropeptides that are consistent with their reduced locomotor activity, and increased sleep. Finally, we find that in a nutrient-deprived environment, the sleep responses of individual D. mojavensis are correlated with their survival time. Our results demonstrate that D. mojavensis is a novel model for studying organisms with high sleep need, and for exploring sleep strategies that provide resilience in extreme environments.
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Affiliation(s)
- Jessica Yano
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Molecular, Cellular & Integrative Physiology Interdepartmental PhD Program, UCLA, Los Angeles, CA 90095, USA
| | - Ceazar Nave
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Katherine Larratt
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Phia Honey
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Department of Neuroscience, Wellesley College, Wellesley, MA 02481, USA
| | - Cassandra Jingco
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Makayla Roberts
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Damion Trotter
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Molecular, Cellular & Integrative Physiology Interdepartmental PhD Program, UCLA, Los Angeles, CA 90095, USA
| | - Xin He
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Gazmend Elezi
- Pasarow Mass Spectrometry Laboratory, Jane & Terry Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Cotsen Institute of Archaeology, UCLA, Los Angeles, CA 90095, USA
| | - Julian P. Whitelegge
- Pasarow Mass Spectrometry Laboratory, Jane & Terry Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Sara Wasserman
- Department of Neuroscience, Wellesley College, Wellesley, MA 02481, USA
| | - Jeffrey M. Donlea
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
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20
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Mohan P, Sinu PA. Is direct bodyguard manipulation a parasitoid-induced stress sleep? A new perspective. Biol Lett 2022; 18:20220280. [PMID: 36448293 PMCID: PMC9709512 DOI: 10.1098/rsbl.2022.0280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 11/08/2022] [Indexed: 12/02/2022] Open
Abstract
Bodyguard manipulation is a behavioural manipulation in which the host's behaviour is altered to protect the inducer's offspring from imminent biotic threats. The behaviour of a post-parasitoid-egressed host resembles a quiescence state with a characteristic reduction in motor activities like feeding, locomotion, respiration, and metabolic rate. Yet, they respond aggressively through a defensive response when disturbed, which ensures better fitness for the parasitoid's offspring. The behavioural changes in the parasitized host appear after the parasitoid egression. Several hypotheses have been proposed to elucidate how the parasitized host's behaviour is manipulated for the fitness benefits of the inducers, but the exact mechanism is still unknown. We review evidence to explain the behavioural changes and their mechanism in the parasitized hosts. The evidence suggests that parasitoid pre-pupal egression may drive the host to stress-induced sleep. The elevated octopamine concentration also reflects the stress response in the host. Given the theoretical links between the behavioural and the physiological changes in the post-parasitoid-egressed host and stress-induced sleep of other invertebrates, we suggest that behavioural studies combined with functional genomics, proteomics, and histological analyses might give a better understanding of bodyguard manipulation.
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Affiliation(s)
- Prabitha Mohan
- Department of Zoology, Central University of Kerala, Kasaragod, Kerala, India
- Zoological Survey of India, Chennai, Tamilnadu, India
| | - Palatty Allesh Sinu
- Department of Zoology, Central University of Kerala, Kasaragod, Kerala, India
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21
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Brown EB, Klok J, Keene AC. Measuring metabolic rate in single flies during sleep and waking states via indirect calorimetry. J Neurosci Methods 2022; 376:109606. [PMID: 35483506 PMCID: PMC9310448 DOI: 10.1016/j.jneumeth.2022.109606] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 04/13/2022] [Accepted: 04/18/2022] [Indexed: 11/23/2022]
Abstract
BACKGROUND Drosophila melanogaster is a leading genetic model for studying the neural regulation of sleep. Sleep is associated with changes in behavior and physiological state that are largely conserved across species. The investigation of sleep in flies has predominantly focused on behavioral readouts of sleep because physiological measurements, including changes in brain activity and metabolic rate, are less accessible. We have previously used stop-flow indirect calorimetry to measure whole body metabolic rate in single flies and have shown that in flies, like mammals, metabolic rate is reduced during sleep. NEW METHOD Here, we describe a modified version of this system that allows for efficient and highly sensitive acquisition of CO2 output from single flies. RESULTS In this modified system, we show that sleep-dependent changes in metabolic rate are diminished in aging flies, supporting the notion that sleep quality is reduced as flies age. We also describe a modification that allows for simultaneous acquisition of CO2 and O2 levels, providing a respiratory quotient that quantifies how metabolic stores are utilized. We find that the respiratory quotient identified in flies on an all-sugar diet is suggestive of lipogenesis, where the dietary sugar provided to the flies is being converted to fat. COMPARISON WITH EXISTING METHODS AND CONCLUSIONS Taken together, the measurement of metabolic rate via indirect calorimetry not only provides a physiological readout of sleep depth, but also provides insight the metabolic regulation of nutrient utilization, with broad applications to genetic studies in flies.
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Affiliation(s)
- Elizabeth B Brown
- Department of Biology, Texas A&M University, College Station, TX 77843, USA
| | - Jaco Klok
- Sable Systems International, Las Vegas, NV 89032, USA
| | - Alex C Keene
- Department of Biology, Texas A&M University, College Station, TX 77843, USA.
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22
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Abstract
Energy derived from food is a precious resource to animals. Those finite calories are often well-earned through exhaustive foraging effort, which can dominate waking hours, to support physiological processes (e.g. body maintenance and growth) and ecological necessities (e.g. predator avoidance and courting) that are pertinent to the production of progeny. So, it is unsurprising to find that animals have evolved strategies to guard against the gratuitous waste of hard-won caloric energy. Yet, it remains surprising to find such diversity, and elegant creativity, in those solutions. Brief examples of energy-saving innovation could include the very shape of animals and how they move, from streamlined swimming sharks to skyward-soaring seabirds; or the evolutionary appearance of various states of dormancy, such as endothermic animals sacrificing high body temperature through modest (torpor) or severe (hibernation) curtailments to metabolic heat production. Another reversibly dormant state with energetic benefits is sleep.
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Affiliation(s)
- John A Lesku
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Australia.
| | - Markus H Schmidt
- Department of Neurology, Center for Experimental Neurology, Bern University Hospital (Inselspital), Bern, Switzerland; Ohio Sleep Medicine Institute, Dublin, OH, USA.
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23
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Kelly ML, Collins SP, Lesku JA, Hemmi JM, Collin SP, Radford CA. Energy conservation characterizes sleep in sharks. Biol Lett 2022; 18:20210259. [PMID: 35259943 PMCID: PMC8915397 DOI: 10.1098/rsbl.2021.0259] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Sharks represent the earliest group of jawed vertebrates and as such, they may provide original insight for understanding the evolution of sleep in more derived animals. Unfortunately, beyond a single behavioural investigation, very little is known about sleep in these ancient predators. As such, recordings of physiological indicators of sleep in sharks have never been reported. Reduced energy expenditure arising from sustained restfulness and lowered metabolic rate during sleep have given rise to the hypothesis that sleep plays an important role for energy conservation. To determine whether this idea applies also to sharks, we compared metabolic rates of draughtsboard sharks (Cephaloscyllium isabellum) during periods ostensibly thought to be sleep, along with restful and actively swimming sharks across a 24 h period. We also investigated behaviours that often characterize sleep in other animals, including eye closure and postural recumbency, to establish relationships between physiology and behaviour. Overall, lower metabolic rate and a flat body posture reflect sleep in draughtsboard sharks, whereas eye closure is a poorer indication of sleep. Our results support the idea for the conservation of energy as a function of sleep in these basal vertebrates.
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Affiliation(s)
- Michael L Kelly
- School of Life Sciences, La Trobe University, Melbourne, Australia
| | - Selwyn P Collins
- Institute of Marine Science, Leigh Marine Laboratory, The University of Auckland, Auckland, New Zealand
| | - John A Lesku
- School of Life Sciences, La Trobe University, Melbourne, Australia
| | - Jan M Hemmi
- School of Biological Sciences, The University of Western Australia, Perth, Australia.,Oceans Institute, The University of Western Australia, Perth, Australia
| | - Shaun P Collin
- School of Life Sciences, La Trobe University, Melbourne, Australia.,Oceans Institute, The University of Western Australia, Perth, Australia.,Oceans Graduate School, The University of Western Australia, Perth, Australia
| | - Craig A Radford
- Institute of Marine Science, Leigh Marine Laboratory, The University of Auckland, Auckland, New Zealand
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24
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Abstract
Sleep is critical for diverse aspects of brain function in animals ranging from invertebrates to humans. Powerful genetic tools in the fruit fly Drosophila melanogaster have identified - at an unprecedented level of detail - genes and neural circuits that regulate sleep. This research has revealed that the functions and neural principles of sleep regulation are largely conserved from flies to mammals. Further, genetic approaches to studying sleep have uncovered mechanisms underlying the integration of sleep and many different biological processes, including circadian timekeeping, metabolism, social interactions, and aging. These findings show that in flies, as in mammals, sleep is not a single state, but instead consists of multiple physiological and behavioral states that change in response to the environment, and is shaped by life history. Here, we review advances in the study of sleep in Drosophila, discuss their implications for understanding the fundamental functions of sleep that are likely to be conserved among animal species, and identify important unanswered questions in the field.
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Affiliation(s)
- Orie T Shafer
- The Advanced Science Research Center, City University of New York, New York, NY 10031, USA.
| | - Alex C Keene
- Department of Biological Science, Florida Atlantic University, Jupiter, FL 33458, USA.
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25
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Botero V, Stanhope BA, Brown EB, Grenci EC, Boto T, Park SJ, King LB, Murphy KR, Colodner KJ, Walker JA, Keene AC, Ja WW, Tomchik SM. Neurofibromin regulates metabolic rate via neuronal mechanisms in Drosophila. Nat Commun 2021; 12:4285. [PMID: 34257279 PMCID: PMC8277851 DOI: 10.1038/s41467-021-24505-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 06/16/2021] [Indexed: 01/21/2023] Open
Abstract
Neurofibromatosis type 1 is a chronic multisystemic genetic disorder that results from loss of function in the neurofibromin protein. Neurofibromin may regulate metabolism, though the underlying mechanisms remain largely unknown. Here we show that neurofibromin regulates metabolic homeostasis in Drosophila via a discrete neuronal circuit. Loss of neurofibromin increases metabolic rate via a Ras GAP-related domain-dependent mechanism, increases feeding homeostatically, and alters lipid stores and turnover kinetics. The increase in metabolic rate is independent of locomotor activity, and maps to a sparse subset of neurons. Stimulating these neurons increases metabolic rate, linking their dynamic activity state to metabolism over short time scales. Our results indicate that neurofibromin regulates metabolic rate via neuronal mechanisms, suggest that cellular and systemic metabolic alterations may represent a pathophysiological mechanism in neurofibromatosis type 1, and provide a platform for investigating the cellular role of neurofibromin in metabolic homeostasis. Neurofibromatosis type 1 (NF1) is a genetic disorder caused by mutations in neurofibromin and associated with disruptions in physiology and behavior. Here the authors show that neurofibromin regulates metabolic homeostasis via a discrete brain circuit in a Drosophila model of NF1.
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Affiliation(s)
- Valentina Botero
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL, USA
| | - Bethany A Stanhope
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL, USA
| | - Elizabeth B Brown
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL, USA
| | - Eliza C Grenci
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL, USA
| | - Tamara Boto
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL, USA.,Department of Physiology, Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
| | - Scarlet J Park
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL, USA
| | - Lanikea B King
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL, USA
| | - Keith R Murphy
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL, USA
| | - Kenneth J Colodner
- Program in Neuroscience and Behavior, Mount Holyoke College, South Hadley, MA, USA
| | - James A Walker
- Center for Genomic Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.,Cancer Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Alex C Keene
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL, USA
| | - William W Ja
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL, USA
| | - Seth M Tomchik
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL, USA.
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26
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van Alphen B, Semenza ER, Yap M, van Swinderen B, Allada R. A deep sleep stage in Drosophila with a functional role in waste clearance. SCIENCE ADVANCES 2021; 7:7/4/eabc2999. [PMID: 33523916 PMCID: PMC7817094 DOI: 10.1126/sciadv.abc2999] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 12/02/2020] [Indexed: 06/12/2023]
Abstract
Sleep is a highly conserved state, suggesting that sleep's benefits outweigh the increased vulnerability it brings. Yet, little is known about how sleep fulfills its functions. Here, we used video tracking in tethered flies to identify a discrete deep sleep stage in Drosophila, termed proboscis extension sleep, that is defined by repeated stereotyped proboscis extensions and retractions. Proboscis extension sleep is accompanied by highly elevated arousal thresholds and decreased brain activity, indicative of a deep sleep state. Preventing proboscis extensions increases injury-related mortality and reduces waste clearance. Sleep deprivation reduces waste clearance and during subsequent rebound sleep, sleep, proboscis extensions, and waste clearance are increased. Together, these results provide evidence of a discrete deep sleep stage that is linked to a specific function and suggest that waste clearance is a core and ancient function of deep sleep.
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Affiliation(s)
- Bart van Alphen
- The Department of Neurobiology, Northwestern University, 2205 Tech Drive, Hogan 2-160, Evanston, Illinois 60208, USA.
| | - Evan R Semenza
- The Department of Neurobiology, Northwestern University, 2205 Tech Drive, Hogan 2-160, Evanston, Illinois 60208, USA
| | - Melvyn Yap
- The Queensland Brain Institute, QBI Building, 79, The University of Queensland, St. Lucia QLD 4072, Australia
| | - Bruno van Swinderen
- The Queensland Brain Institute, QBI Building, 79, The University of Queensland, St. Lucia QLD 4072, Australia
| | - Ravi Allada
- The Department of Neurobiology, Northwestern University, 2205 Tech Drive, Hogan 2-160, Evanston, Illinois 60208, USA.
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27
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Zhou X, Ding G, Li J, Xiang X, Rushworth E, Song W. Physiological and Pathological Regulation of Peripheral Metabolism by Gut-Peptide Hormones in Drosophila. Front Physiol 2020; 11:577717. [PMID: 33117196 PMCID: PMC7552570 DOI: 10.3389/fphys.2020.577717] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 09/07/2020] [Indexed: 12/18/2022] Open
Abstract
The gastrointestinal (GI) tract in both vertebrates and invertebrates is now recognized as a major source of signals modulating, via gut-peptide hormones, the metabolic activities of peripheral organs, and carbo-lipid balance. Key advances in the understanding of metabolic functions of gut-peptide hormones and their mediated interorgan communication have been made using Drosophila as a model organism, given its powerful genetic tools and conserved metabolic regulation. Here, we summarize recent studies exploring peptide hormones that are involved in the communication between the midgut and other peripheral organs/tissues during feeding conditions. We also highlight the emerging impacts of fly gut-peptide hormones on stress sensing and carbo-lipid metabolism in various disease models, such as energy overload, pathogen infection, and tumor progression. Due to the functional similarity of intestine and its derived peptide hormones between Drosophila and mammals, it can be anticipated that findings obtained in the fly system will have important implications for the understanding of human physiology and pathology.
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Affiliation(s)
- Xiaoya Zhou
- Department of Oncology, Renmin Hospital of Wuhan University, Wuhan, China.,Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
| | - Guangming Ding
- Department of Oncology, Renmin Hospital of Wuhan University, Wuhan, China.,Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
| | - Jiaying Li
- Department of Oncology, Renmin Hospital of Wuhan University, Wuhan, China.,Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
| | - Xiaoxiang Xiang
- Department of Oncology, Renmin Hospital of Wuhan University, Wuhan, China.,Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
| | - Elisabeth Rushworth
- Department of Oncology, Renmin Hospital of Wuhan University, Wuhan, China.,Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
| | - Wei Song
- Department of Oncology, Renmin Hospital of Wuhan University, Wuhan, China.,Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
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28
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Vázquez DE, Balbuena MS, Chaves F, Gora J, Menzel R, Farina WM. Sleep in honey bees is affected by the herbicide glyphosate. Sci Rep 2020; 10:10516. [PMID: 32601296 PMCID: PMC7324403 DOI: 10.1038/s41598-020-67477-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 06/05/2020] [Indexed: 02/02/2023] Open
Abstract
Sleep plays an essential role in both neural and energetic homeostasis of animals. Honey bees (Apis mellifera) manifest the sleep state as a reduction in muscle tone and antennal movements, which is susceptible to physical or chemical disturbances. This social insect is one of the most important pollinators in agricultural ecosystems, being exposed to a great variety of agrochemicals, which might affect its sleep behaviour. The intake of glyphosate (GLY), the herbicide most widely used worldwide, impairs learning, gustatory responsiveness and navigation in honey bees. In general, these cognitive abilities are linked with the amount and quality of sleep. Furthermore, it has been reported that animals exposed to sleep disturbances show impairments in both metabolism and memory consolidation. Consequently, we assessed the sleep pattern of bees fed with a sugar solution containing GLY (0, 25, 50 and 100 ng) by quantifying their antennal activity during the scotophase. We found that the ingestion of 50 ng of GLY decreased both antennal activity and sleep bout frequency. This sleep deepening after GLY intake could be explained as a consequence of the regenerative function of sleep and the metabolic stress induced by the herbicide.
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Affiliation(s)
- Diego E Vázquez
- Laboratorio de Insectos Sociales, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - M Sol Balbuena
- Laboratorio de Insectos Sociales, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Fidel Chaves
- Laboratorio de Insectos Sociales, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Jacob Gora
- Institut für Biologie, Freie Universität Berlin, Berlin, Germany
| | - Randolf Menzel
- Institut für Biologie, Freie Universität Berlin, Berlin, Germany
| | - Walter M Farina
- Laboratorio de Insectos Sociales, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina.
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29
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Northeast RC, Vyazovskiy VV, Bechtold DA. Eat, sleep, repeat: the role of the circadian system in balancing sleep-wake control with metabolic need. CURRENT OPINION IN PHYSIOLOGY 2020; 15:183-191. [PMID: 32617440 PMCID: PMC7323618 DOI: 10.1016/j.cophys.2020.02.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Feeding and sleep are behaviours fundamental to survival, and as such are subject to powerful homeostatic control. Of course, these are mutually exclusive behaviours, and therefore require coordinated temporal organisation to ensure that both energy demands and sleep need are met. Under optimal conditions, foraging/feeding and sleep can be simply partitioned to appropriate phases of the circadian cycle so that they are in suitable alignment with the external environment. However, under conditions of negative energy balance, increased foraging activity must be balanced against sleep requirements and energy conservation. In mammals and many other species, neural circuits that regulate sleep and energy balance are intimately and reciprocally linked. Here, we examine this circuitry, discuss how homeostatic regulation and temporal patterning of sleep are modulated by altered food availability, and describe the role of circadian system in adaptation to metabolic stress.
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Affiliation(s)
- Rebecca C Northeast
- Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
| | - Vladyslav V Vyazovskiy
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK
| | - David A Bechtold
- Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
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30
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Dissel S. Drosophila as a Model to Study the Relationship Between Sleep, Plasticity, and Memory. Front Physiol 2020; 11:533. [PMID: 32547415 PMCID: PMC7270326 DOI: 10.3389/fphys.2020.00533] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 04/30/2020] [Indexed: 12/28/2022] Open
Abstract
Humans spend nearly a third of their life sleeping, yet, despite decades of research the function of sleep still remains a mystery. Sleep has been linked with various biological systems and functions, including metabolism, immunity, the cardiovascular system, and cognitive functions. Importantly, sleep appears to be present throughout the animal kingdom suggesting that it must provide an evolutionary advantage. Among the many possible functions of sleep, the relationship between sleep, and cognition has received a lot of support. We have all experienced the negative cognitive effects associated with a night of sleep deprivation. These can include increased emotional reactivity, poor judgment, deficit in attention, impairment in learning and memory, and obviously increase in daytime sleepiness. Furthermore, many neurological diseases like Alzheimer’s disease often have a sleep disorder component. In some cases, the sleep disorder can exacerbate the progression of the neurological disease. Thus, it is clear that sleep plays an important role for many brain functions. In particular, sleep has been shown to play a positive role in the consolidation of long-term memory while sleep deprivation negatively impacts learning and memory. Importantly, sleep is a behavior that is adapted to an individual’s need and influenced by many external and internal stimuli. In addition to being an adaptive behavior, sleep can also modulate plasticity in the brain at the level of synaptic connections between neurons and neuronal plasticity influences sleep. Understanding how sleep is modulated by internal and external stimuli and how sleep can modulate memory and plasticity is a key question in neuroscience. In order to address this question, several animal models have been developed. Among them, the fruit fly Drosophila melanogaster with its unparalleled genetics has proved to be extremely valuable. In addition to sleep, Drosophila has been shown to be an excellent model to study many complex behaviors, including learning, and memory. This review describes our current knowledge of the relationship between sleep, plasticity, and memory using the fly model.
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Affiliation(s)
- Stephane Dissel
- Department of Molecular Biology and Biochemistry, School of Biological and Chemical Sciences, University of Missouri-Kansas City, Kansas City, MO, United States
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31
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Grubbs JJ, Lopes LE, van der Linden AM, Raizen DM. A salt-induced kinase is required for the metabolic regulation of sleep. PLoS Biol 2020; 18:e3000220. [PMID: 32315298 PMCID: PMC7173979 DOI: 10.1371/journal.pbio.3000220] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 03/20/2020] [Indexed: 12/16/2022] Open
Abstract
Many lines of evidence point to links between sleep regulation and energy homeostasis, but mechanisms underlying these connections are unknown. During Caenorhabditis elegans sleep, energetic stores are allocated to nonneural tasks with a resultant drop in the overall fat stores and energy charge. Mutants lacking KIN-29, the C. elegans homolog of a mammalian Salt-Inducible Kinase (SIK) that signals sleep pressure, have low ATP levels despite high-fat stores, indicating a defective response to cellular energy deficits. Liberating energy stores corrects adiposity and sleep defects of kin-29 mutants. kin-29 sleep and energy homeostasis roles map to a set of sensory neurons that act upstream of fat regulation as well as of central sleep-controlling neurons, suggesting hierarchical somatic/neural interactions regulating sleep and energy homeostasis. Genetic interaction between kin-29 and the histone deacetylase hda-4 coupled with subcellular localization studies indicate that KIN-29 acts in the nucleus to regulate sleep. We propose that KIN-29/SIK acts in nuclei of sensory neuroendocrine cells to transduce low cellular energy charge into the mobilization of energy stores, which in turn promotes sleep.
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Affiliation(s)
- Jeremy J. Grubbs
- Department of Biology, University of Nevada, Reno, Nevada, United States of America
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Lindsey E. Lopes
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | | | - David M. Raizen
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
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32
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Brown EB, Shah KD, Faville R, Kottler B, Keene AC. Drosophila insulin-like peptide 2 mediates dietary regulation of sleep intensity. PLoS Genet 2020; 16:e1008270. [PMID: 32160200 PMCID: PMC7089559 DOI: 10.1371/journal.pgen.1008270] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 03/23/2020] [Accepted: 12/06/2019] [Indexed: 01/30/2023] Open
Abstract
Sleep is a nearly universal behavior that is regulated by diverse environmental stimuli and physiological states. A defining feature of sleep is a homeostatic rebound following deprivation, where animals compensate for lost sleep by increasing sleep duration and/or sleep depth. The fruit fly, Drosophila melanogaster, exhibits robust recovery sleep following deprivation and represents a powerful model to study neural circuits regulating sleep homeostasis. Numerous neuronal populations have been identified in modulating sleep homeostasis as well as depth, raising the possibility that the duration and quality of recovery sleep is dependent on the environmental or physiological processes that induce sleep deprivation. Here, we find that unlike most pharmacological and environmental manipulations commonly used to restrict sleep, starvation potently induces sleep loss without a subsequent rebound in sleep duration or depth. Both starvation and a sucrose-only diet result in increased sleep depth, suggesting that dietary protein is essential for normal sleep depth and homeostasis. Finally, we find that Drosophila insulin like peptide 2 (Dilp2) is acutely required for starvation-induced changes in sleep depth without regulating the duration of sleep. Flies lacking Dilp2 exhibit a compensatory sleep rebound following starvation-induced sleep deprivation, suggesting Dilp2 promotes resiliency to sleep loss. Together, these findings reveal innate resilience to starvation-induced sleep loss and identify distinct mechanisms that underlie starvation-induced changes in sleep duration and depth. Sleep is nearly universal throughout the animal kingdom and homeostatic regulation represents a defining feature of sleep, where animals compensate for lost sleep by increasing sleep over subsequent time periods. Despite the robustness of this feature, the neural mechanisms regulating recovery from different types of sleep deprivation are not fully understood. Fruit flies provide a powerful model for investigating the genetic regulation of sleep, and like mammals, display robust recovery sleep following deprivation. Here, we find that unlike most stimuli that suppress sleep, sleep deprivation by starvation does not require a homeostatic rebound. These findings are likely due to flies engaging in deeper sleep during the period of partial sleep deprivation, suggesting a natural resilience to starvation-induced sleep loss. This unique resilience to starvation-induced sleep loss is dependent on Drosophila insulin-like peptide 2, revealing a critical role for insulin signaling in regulating interactions between diet and sleep homeostasis.
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Affiliation(s)
- Elizabeth B. Brown
- Department of Biological Sciences, Florida Atlantic University, Jupiter, Florida, United States of America
| | - Kreesha D. Shah
- Department of Biological Sciences, Florida Atlantic University, Jupiter, Florida, United States of America
- Wilkes Honors College, Florida Atlantic University, Jupiter, Florida, United States of America
| | | | | | - Alex C. Keene
- Department of Biological Sciences, Florida Atlantic University, Jupiter, Florida, United States of America
- * E-mail:
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33
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Dissel S, Morgan E, Duong V, Chan D, van Swinderen B, Shaw P, Zars T. Sleep restores place learning to the adenylyl cyclase mutant rutabaga. J Neurogenet 2020; 34:83-91. [PMID: 31997683 PMCID: PMC7250152 DOI: 10.1080/01677063.2020.1720674] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 01/20/2020] [Indexed: 01/29/2023]
Abstract
Sleep plays an important role in regulating plasticity. In Drosophila, the relationship between sleep and learning and memory has primarily focused on mushroom body dependent operant-learning assays such as aversive phototaxic suppression and courtship conditioning. In this study, sleep was increased in the classic mutant rutabaga (rut2080) and dunce (dnc1) by feeding them the GABA-A agonist gaboxadol (Gab). Performance was evaluated in each mutant in response to social enrichment and place learning, tasks that do not require the mushroom body. Gab-induced sleep did not restore behavioral plasticity to either rut2080 or dnc1 mutants following social enrichment. However, increased sleep restored place learning to rut2080 mutants. These data extend the positive effects of enhanced sleep to place learning and highlight the utility of Gab for elucidating the beneficial effects of sleep on brain functioning.
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Affiliation(s)
- Stephane Dissel
- School of Biological and Chemical Sciences, University of Missouri-Kansas City, 5007 Rockhill Rd, Kansas City, MO 64110
- Department of Neuroscience, Washington University in St. Louis, 660 S. Euclid Ave, St. Louis, Missouri, U.S.A
| | - Ellen Morgan
- Department of Neuroscience, Washington University in St. Louis, 660 S. Euclid Ave, St. Louis, Missouri, U.S.A
| | - Vincent Duong
- Department of Neuroscience, Washington University in St. Louis, 660 S. Euclid Ave, St. Louis, Missouri, U.S.A
| | - Dorothy Chan
- Department of Neuroscience, Washington University in St. Louis, 660 S. Euclid Ave, St. Louis, Missouri, U.S.A
| | - Bruno van Swinderen
- The Queensland Brain Institute, University of Queensland, Brisbane Qld 4072 Australia
| | - Paul Shaw
- Department of Neuroscience, Washington University in St. Louis, 660 S. Euclid Ave, St. Louis, Missouri, U.S.A
| | - Troy Zars
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States of America
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Pamboro ELS, Brown EB, Keene AC. Dietary fatty acids promote sleep through a taste-independent mechanism. GENES BRAIN AND BEHAVIOR 2020; 19:e12629. [PMID: 31845509 DOI: 10.1111/gbb.12629] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 12/04/2019] [Accepted: 12/05/2019] [Indexed: 01/28/2023]
Abstract
Consumption of foods that are high in fat contribute to obesity and metabolism-related disorders. Dietary lipids are comprised of triglycerides and fatty acids, and the highly palatable taste of dietary fatty acids promotes food consumption, activates reward centers in mammals and underlies hedonic feeding. Despite the central role of dietary fats in the regulation of food intake and the etiology of metabolic diseases, little is known about how fat consumption regulates sleep. The fruit fly, Drosophila melanogaster, provides a powerful model system for the study of sleep and metabolic traits, and flies potently regulate sleep in accordance with food availability. To investigate the effects of dietary fats on sleep regulation, we have supplemented fatty acids into the diet of Drosophila and measured their effects on sleep and activity. We found that flies fed a diet of hexanoic acid, a medium-chain fatty acid that is a by-product of yeast fermentation, slept more than flies starved on an agar diet. To assess whether dietary fatty acids regulate sleep through the taste system, we assessed sleep in flies with a mutation in the hexanoic acid receptor Ionotropic receptor 56D, which is required for fatty acid taste perception. We found that these flies also sleep more than agar-fed flies when fed a hexanoic acid diet, suggesting the sleep promoting effect of hexanoic acid is not dependent on sensory perception. Taken together, these findings provide a platform to investigate the molecular and neural basis for fatty acid-dependent modulation of sleep.
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Affiliation(s)
- Estelle L S Pamboro
- Department of Biological Sciences, Florida Atlantic University, Jupiter, Florida
| | - Elizabeth B Brown
- Department of Biological Sciences, Florida Atlantic University, Jupiter, Florida
| | - Alex C Keene
- Department of Biological Sciences, Florida Atlantic University, Jupiter, Florida
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35
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Videlier M, Rundle HD, Careau V. Sex-Specific Among-Individual Covariation in Locomotor Activity and Resting Metabolic Rate in Drosophila melanogaster. Am Nat 2019; 194:E164-E176. [PMID: 31738101 DOI: 10.1086/705678] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
A key endeavor in evolutionary physiology is to identify sources of among- and within-individual variation in resting metabolic rate (RMR). Although males and females often differ in whole-organism RMR due to sexual size dimorphism, sex differences in RMR sometimes persist after conditioning on body mass, suggesting phenotypic differences between males and females in energy-expensive activities contributing to RMR. One potential difference is locomotor activity, yet its relationship with RMR is unclear and different energy budget models predict different associations. We quantified locomotor activity (walking) over 24 h and RMR (overnight) in 232 male and 245 female Drosophila melanogaster that were either mated or maintained as virgins between two sets of measurements. Accounting for body mass, sex, and reproductive status, RMR and activity were significantly and moderately repeatable (RMR: R=0.33±0.06; activity: R=0.58±0.03). RMR and activity were positively correlated among (rind=0.26±0.09) but not within (re=0.05±0.06) individuals. Moreover, activity varied throughout the day and between the sexes. Partitioning our analysis by sex and activity by time of day revealed that all among-individual correlations were positive and significant in males but nonsignificant or even significantly negative in females. Such differences in the RMR-activity covariance suggest fundamental differences in how the sexes manage their energy budget.
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36
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Beckwith EJ, French AS. Sleep in Drosophila and Its Context. Front Physiol 2019; 10:1167. [PMID: 31572216 PMCID: PMC6749028 DOI: 10.3389/fphys.2019.01167] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 08/29/2019] [Indexed: 12/17/2022] Open
Abstract
A prominent idea emerging from the study of sleep is that this key behavioural state is regulated in a complex fashion by ecologically and physiologically relevant environmental factors. This concept implies that sleep, as a behaviour, is plastic and can be regulated by external agents and changes in internal state. Drosophila melanogaster constitutes a resourceful model system to study behaviour. In the year 2000, the utility of the fly to study sleep was realised, and has since extensively contributed to this exciting field. At the centre of this review, we will discuss studies showing that temperature, food availability/quality, and interactions with conspecifics can regulate sleep. Indeed the relationship can be reciprocal and sleep perturbation can also affect feeding and social interaction. In particular, different environmental temperatures as well as gradual changes in temperature regulate when, and how much flies sleep. Moreover, the satiation/starvation status of an individual dictates the balance between sleep and foraging. Nutritional composition of diet also has a direct impact on sleep amount and its fragmentation. Likewise, aggression between males, courtship, sexual arousal, mating, and interactions within large groups of animals has an acute and long-lasting effect on sleep amount and quality. Importantly, the genes and neuronal circuits that relay information about the external environment and internal state to sleep centres are starting to be elucidated in the fly and are the focus of this review. In conclusion, sleep, as with most behaviours, needs the full commitment of the individual, preventing participation in other vital activities. A vast array of behaviours that are modulated by external and internal factors compete with the need to sleep and thus have a significant role in regulating it.
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Affiliation(s)
- Esteban J Beckwith
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Alice S French
- Department of Life Sciences, Imperial College London, London, United Kingdom
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37
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Miura M, Takahashi A. Starvation tolerance associated with prolonged sleep bouts upon starvation in a single natural population of Drosophila melanogaster. J Evol Biol 2019; 32:1117-1123. [PMID: 31381200 PMCID: PMC6851687 DOI: 10.1111/jeb.13514] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 07/11/2019] [Accepted: 07/30/2019] [Indexed: 12/16/2022]
Abstract
Large genetic variations in starvation tolerance in animals indicate that there are multiple strategies to cope with low-nutrient conditions. Fruit flies (Drosophila melanogaster) typically respond to starvation by suppressing sleep and enhancing locomotor activity presumably to search for food. However, we hypothesized that in a natural population, there are costs and benefits to sleep suppression under low-nutrient conditions and that conserving energy through sleep could be a better strategy depending on food availability. In this study, we quantified the variation in sleep-related traits in 21 wild-derived inbred lines from Katsunuma, Japan, under fed and starved conditions and analysed the relationship between those traits and starvation tolerance. Although most of the lines responded to starvation by suppressing the total time in sleep, there were indeed two lines that responded by significantly increasing the sleep-bout durations and thus not reducing the total time in sleep. These genotypes survived longer in acute starvation conditions compared to genotypes that responded by the immediate suppression of sleep, which could be due to the reduced metabolic rate during the long uninterrupted sleep bouts. The coexistence of the enhanced foraging and resting strategies upon starvation within a single population is consistent with the presence of a behavioural trade-off between food search and energy conservation due to unpredictable food availability in nature. These results provide insights into the evolutionary mechanisms that contribute to the maintenance of genetic variations underlying environmental stress resistance.
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Affiliation(s)
- Mai Miura
- Department of Biological Sciences, Tokyo Metropolitan University, Hachioji, Japan
| | - Aya Takahashi
- Department of Biological Sciences, Tokyo Metropolitan University, Hachioji, Japan.,Research Center for Genomics and Bioinformatics, Tokyo Metropolitan University, Hachioji, Japan
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38
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Yurgel ME, Keene AC. Sleep: Helicon Cells Charge the Circuit. Curr Biol 2019; 28:R317-R319. [PMID: 29614291 DOI: 10.1016/j.cub.2018.02.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new study in the fruit fly, Drosophila melanogaster, has identified a neural circuitry that connects regions that control sleep with those that encode sleep pressure. These novel cells, termed helicon cells for their unique morphology, are modulated by sleep control centers and integrate sensory information, providing a novel mechanism for gating of sleep.
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Affiliation(s)
- Maria E Yurgel
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Alex C Keene
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL 33458, USA.
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39
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Brown EB, Slocumb ME, Szuperak M, Kerbs A, Gibbs AG, Kayser MS, Keene AC. Starvation resistance is associated with developmentally specified changes in sleep, feeding and metabolic rate. J Exp Biol 2019; 222:jeb191049. [PMID: 30606795 PMCID: PMC6381993 DOI: 10.1242/jeb.191049] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 12/11/2018] [Indexed: 11/20/2022]
Abstract
Food shortage represents a primary challenge to survival, and animals have adapted diverse developmental, physiological and behavioral strategies to survive when food becomes unavailable. Starvation resistance is strongly influenced by ecological and evolutionary history, yet the genetic basis for the evolution of starvation resistance remains poorly understood. The fruit fly Drosophila melanogaster provides a powerful model for leveraging experimental evolution to investigate traits associated with starvation resistance. While control populations only live a few days without food, selection for starvation resistance results in populations that can survive weeks. We have previously shown that selection for starvation resistance results in increased sleep and reduced feeding in adult flies. Here, we investigate the ontogeny of starvation resistance-associated behavioral and metabolic phenotypes in these experimentally selected flies. We found that selection for starvation resistance resulted in delayed development and a reduction in metabolic rate in larvae that persisted into adulthood, suggesting that these traits may allow for the accumulation of energy stores and an increase in body size within these selected populations. In addition, we found that larval sleep was largely unaffected by starvation selection and that feeding increased during the late larval stages, suggesting that experimental evolution for starvation resistance produces developmentally specified changes in behavioral regulation. Together, these findings reveal a critical role for development in the evolution of starvation resistance and indicate that selection can selectively influence behavior during defined developmental time points.
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Affiliation(s)
- Elizabeth B Brown
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Melissa E Slocumb
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Milan Szuperak
- Departments of Psychiatry and Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Arianna Kerbs
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Allen G Gibbs
- Department of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV 89154, USA
| | - Matthew S Kayser
- Departments of Psychiatry and Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Alex C Keene
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL 33458, USA
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40
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Dubowy C, Kayser MS. Sleep and Metabolism: Eaat-ing Your Way to ZZZs. Curr Biol 2018; 28:R1310-R1312. [PMID: 30458152 DOI: 10.1016/j.cub.2018.08.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A new study in fruit flies identifies a molecule, Eaat2, that regulates both sleep and metabolic rate. Surprisingly, Eaat2 acts in a specific glial subtype to modulate both processes, suggesting a cellular link in the brain between sleep and metabolism.
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Affiliation(s)
- Christine Dubowy
- Departments of Psychiatry and Neuroscience, Chronobiology Program, and Center for Sleep and Circadian Neurobiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Matthew S Kayser
- Departments of Psychiatry and Neuroscience, Chronobiology Program, and Center for Sleep and Circadian Neurobiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.
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41
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Zandawala M, Yurgel ME, Texada MJ, Liao S, Rewitz KF, Keene AC, Nässel DR. Modulation of Drosophila post-feeding physiology and behavior by the neuropeptide leucokinin. PLoS Genet 2018; 14:e1007767. [PMID: 30457986 PMCID: PMC6245514 DOI: 10.1371/journal.pgen.1007767] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 10/15/2018] [Indexed: 12/12/2022] Open
Abstract
Behavior and physiology are orchestrated by neuropeptides acting as central neuromodulators and circulating hormones. An outstanding question is how these neuropeptides function to coordinate complex and competing behaviors. In Drosophila, the neuropeptide leucokinin (LK) modulates diverse functions, but mechanisms underlying these complex interactions remain poorly understood. As a first step towards understanding these mechanisms, we delineated LK circuitry that governs various aspects of post-feeding physiology and behavior. We found that impaired LK signaling in Lk and Lk receptor (Lkr) mutants affects diverse but coordinated processes, including regulation of stress, water homeostasis, feeding, locomotor activity, and metabolic rate. Next, we sought to define the populations of LK neurons that contribute to the different aspects of this physiology. We find that the calcium activity in abdominal ganglia LK neurons (ABLKs), but not in the two sets of brain neurons, increases specifically following water consumption, suggesting that ABLKs regulate water homeostasis and its associated physiology. To identify targets of LK peptide, we mapped the distribution of Lkr expression, mined a brain single-cell transcriptome dataset for genes coexpressed with Lkr, and identified synaptic partners of LK neurons. Lkr expression in the brain insulin-producing cells (IPCs), gut, renal tubules and chemosensory cells, correlates well with regulatory roles detected in the Lk and Lkr mutants. Furthermore, these mutants and flies with targeted knockdown of Lkr in IPCs displayed altered expression of insulin-like peptides (DILPs) and transcripts in IPCs and increased starvation resistance. Thus, some effects of LK signaling appear to occur via DILP action. Collectively, our data suggest that the three sets of LK neurons have different targets, but modulate the establishment of post-prandial homeostasis by regulating distinct physiological processes and behaviors such as diuresis, metabolism, organismal activity and insulin signaling. These findings provide a platform for investigating feeding-related neuroendocrine regulation of vital behavior and physiology.
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Affiliation(s)
- Meet Zandawala
- Department of Zoology, Stockholm University, Stockholm, Sweden
| | - Maria E. Yurgel
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL, United States of America
| | - Michael J. Texada
- Department of Biology, University of Copenhagen, Universitetsparken 15, Copenhagen, Denmark
| | - Sifang Liao
- Department of Zoology, Stockholm University, Stockholm, Sweden
| | - Kim F. Rewitz
- Department of Biology, University of Copenhagen, Universitetsparken 15, Copenhagen, Denmark
| | - Alex C. Keene
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL, United States of America
| | - Dick R. Nässel
- Department of Zoology, Stockholm University, Stockholm, Sweden
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42
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Abstract
Sleep is nearly ubiquitous throughout the animal kingdom, yet little is known about how ecological factors or perturbations to the environment shape the duration and timing of sleep. In diverse animal taxa, poor sleep negatively impacts development, cognitive abilities and longevity. In addition to mammals, sleep has been characterized in genetic model organisms, ranging from the nematode worm to zebrafish, and, more recently, in emergent models with simplified nervous systems such as Aplysia and jellyfish. In addition, evolutionary models ranging from fruit flies to cavefish have leveraged natural genetic variation to investigate the relationship between ecology and sleep. Here, we describe the contributions of classical and emergent genetic model systems to investigate mechanisms underlying sleep regulation. These studies highlight fundamental interactions between sleep and sensory processing, as well as a remarkable plasticity of sleep in response to environmental changes. Understanding how sleep varies throughout the animal kingdom will provide critical insight into fundamental functions and conserved genetic mechanisms underlying sleep regulation. Furthermore, identification of naturally occurring genetic variation regulating sleep may provide novel drug targets and approaches to treat sleep-related diseases.
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Affiliation(s)
- Alex C Keene
- Jupiter Life Science Initiative, Florida Atlantic University, Jupiter, FL 33458, USA
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Erik R Duboue
- Jupiter Life Science Initiative, Florida Atlantic University, Jupiter, FL 33458, USA
- Wilkes Honors College, Florida Atlantic University, Jupiter, FL 33458, USA
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43
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Donlea JM. Neuronal and molecular mechanisms of sleep homeostasis. CURRENT OPINION IN INSECT SCIENCE 2017; 24:51-57. [PMID: 29208223 DOI: 10.1016/j.cois.2017.09.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 09/13/2017] [Accepted: 09/13/2017] [Indexed: 06/07/2023]
Abstract
Sleep is necessary for survival, and prolonged waking causes a homeostatic increase in the need for recovery sleep. Homeostasis is a core component of sleep regulation and has been tightly conserved across evolution from invertebrates to man. Homeostatic sleep regulation was first identified among insects in cockroaches several decades ago, but the characterization of sleep rebound in Drosophila melanogaster opened the use of insect model species to understand homeostatic functions and regulation of sleep. This review describes circuits in two neuropil structures, the central complex and mushroom bodies, that influence sleep homeostasis and neuromodulatory systems that influence the accrual of homeostatic sleep need.
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Affiliation(s)
- Jeffrey M Donlea
- Department of Neurobiology, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA 90095-1763, USA.
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