1
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Uy G, Farrell LN, Faheem SF, Kinne LE, Adore MG, Im SH, Fairman R. The Effects of poly-GA and poly-PR C9orf72 Dipeptide Repeats on Sleep Patterns in Drosophila melanogaster. MICROPUBLICATION BIOLOGY 2024; 2024:10.17912/micropub.biology.000973. [PMID: 38495583 PMCID: PMC10943360 DOI: 10.17912/micropub.biology.000973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 01/31/2024] [Accepted: 03/01/2024] [Indexed: 03/19/2024]
Abstract
C9orf72 is the most common familial gene associated with amyotrophic lateral sclerosis (ALS). Dipeptide repeats (DPRs) encoded by an expanded nucleotide repeat sequence in the C9orf72 gene were found in the sleep-related neurons of patients, indicating a role of DPRs in ALS-associated sleep disruptions. Poly-GA or poly-PR DPRs were expressed in male Drosophila melanogaster to study their effect on sleep . Poly-PR expression caused sleep disruptions while poly-GA expression did not. This study validates the use of Drosophila as an in vivo model system for exploring the roles of DPRs in perturbing the underlying molecular mechanisms in sleep regulation.
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Affiliation(s)
- Genevieve Uy
- Chemistry, Haverford College, Philadelphia, Pennsylvania, United States
| | - Laura N. Farrell
- Neuroscience, Haverford College, Philadelphia, Pennsylvania, United States
| | - Syeda F. Faheem
- Biology, Haverford College, Philadelphia, Pennsylvania, United States
| | - Lauren E. Kinne
- Biology, Haverford College, Philadelphia, Pennsylvania, United States
| | - Madison G. Adore
- Biology, Haverford College, Philadelphia, Pennsylvania, United States
| | - Seol Hee Im
- Biology, Haverford College, Philadelphia, Pennsylvania, United States
| | - Robert Fairman
- Biology, Haverford College, Philadelphia, Pennsylvania, United States
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2
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Akpoghiran O, Afonso DJS, Zhang Y, Koh K. TARANIS Interacts with VRILLE and PDP1 to Modulate the Circadian Transcriptional Feedback Mechanism in Drosophila. J Neurosci 2024; 44:e0922232023. [PMID: 38296648 PMCID: PMC10860567 DOI: 10.1523/jneurosci.0922-23.2023] [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: 05/15/2023] [Revised: 11/18/2023] [Accepted: 11/22/2023] [Indexed: 02/02/2024] Open
Abstract
The molecular clock that generates daily rhythms of behavior and physiology consists of interlocked transcription-translation feedback loops. In Drosophila, the primary feedback loop involving the CLOCK-CYCLE transcriptional activators and the PERIOD-TIMELESS transcriptional repressors is interlocked with a secondary loop involving VRILLE (VRI) and PAR DOMAIN PROTEIN 1 (PDP1), a repressor and activator of Clock transcription, respectively. Whereas extensive studies have found numerous transcriptional, translational, and posttranslational modulators of the primary loop, relatively little is known about the secondary loop. In this study, using male and female flies as well as cultured cells, we demonstrate that TARANIS (TARA), a Drosophila homolog of the TRIP-Br/SERTAD family of transcriptional coregulators, functions with VRI and PDP1 to modulate the circadian period and rhythm strength. Knocking down tara reduces rhythm amplitude and can shorten the period length, while overexpressing TARA lengthens the circadian period. Additionally, tara mutants exhibit reduced rhythmicity and lower expression of the PDF neuropeptide. We find that TARA can form a physical complex with VRI and PDP1, enhancing their repressor and activator functions, respectively. The conserved SERTA domain of TARA is required to regulate the transcriptional activity of VRI and PDP1, and its deletion leads to reduced locomotor rhythmicity. Consistent with TARA's role in enhancing VRI and PDP1 activity, overexpressing tara has a similar effect on the circadian period and rhythm strength as simultaneously overexpressing vri and Pdp1 Together, our results suggest that TARA modulates circadian behavior by enhancing the transcriptional activity of VRI and PDP1.
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Affiliation(s)
- Oghenerukevwe Akpoghiran
- Department of Neuroscience, the Farber Institute for Neurosciences, and Synaptic Biology Center, Thomas Jefferson University, Philadelphia 19107, Pennsylvania
| | - Dinis J S Afonso
- Department of Neuroscience, the Farber Institute for Neurosciences, and Synaptic Biology Center, Thomas Jefferson University, Philadelphia 19107, Pennsylvania
| | - Yanan Zhang
- Department of Neuroscience, the Farber Institute for Neurosciences, and Synaptic Biology Center, Thomas Jefferson University, Philadelphia 19107, Pennsylvania
| | - Kyunghee Koh
- Department of Neuroscience, the Farber Institute for Neurosciences, and Synaptic Biology Center, Thomas Jefferson University, Philadelphia 19107, Pennsylvania
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3
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Eiman MN, Kumar S, Serrano Negron YL, Tansey TR, Harbison ST. Genome-wide association in Drosophila identifies a role for Piezo and Proc-R in sleep latency. Sci Rep 2024; 14:260. [PMID: 38168575 PMCID: PMC10761942 DOI: 10.1038/s41598-023-50552-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: 03/28/2023] [Accepted: 12/21/2023] [Indexed: 01/05/2024] Open
Abstract
Sleep latency, the amount of time that it takes an individual to fall asleep, is a key indicator of sleep need. Sleep latency varies considerably both among and within species and is heritable, but lacks a comprehensive description of its underlying genetic network. Here we conduct a genome-wide association study of sleep latency. Using previously collected sleep and activity data on a wild-derived population of flies, we calculate sleep latency, confirming significant, heritable genetic variation for this complex trait. We identify 520 polymorphisms in 248 genes contributing to variability in sleep latency. Tests of mutations in 23 candidate genes and additional putative pan-neuronal knockdown of 9 of them implicated CG44153, Piezo, Proc-R and Rbp6 in sleep latency. Two large-effect mutations in the genes Proc-R and Piezo were further confirmed via genetic rescue. This work greatly enhances our understanding of the genetic factors that influence variation in sleep latency.
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Affiliation(s)
- Matthew N Eiman
- Laboratory of Systems Genetics, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
- Drexel University College of Medicine, Philadelphia, PA, USA
| | - Shailesh Kumar
- Laboratory of Systems Genetics, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
- Division of Neuroscience and Behavior, National Institute On Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - Yazmin L Serrano Negron
- Laboratory of Systems Genetics, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Terry R Tansey
- Laboratory of Systems Genetics, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Susan T Harbison
- Laboratory of Systems Genetics, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
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4
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Akpoghiran O, Afonso DJ, Zhang Y, Koh K. TARANIS interacts with VRILLE and PDP1 to modulate the circadian transcriptional feedback mechanism in Drosophila. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.19.541420. [PMID: 38076905 PMCID: PMC10705542 DOI: 10.1101/2023.05.19.541420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
The molecular clock that generates daily rhythms of behavior and physiology consists of interlocked transcription-translation feedback loops. In Drosophila, the primary feedback loop involving the CLOCK-CYCLE transcriptional activators and the PERIOD-TIMELESS transcriptional repressors is interlocked with a secondary loop involving VRILLE (VRI) and PAR DOMAIN PROTEIN 1 (PDP1), a repressor and activator of Clock transcription, respectively. Whereas extensive studies have found numerous transcriptional, translational, and post-translational modulators of the primary loop, relatively little is known about the secondary loop. In this study, using male and female flies as well as cultured cells, we demonstrate that TARANIS (TARA), a Drosophila homolog of the TRIP-Br/SERTAD family of transcriptional coregulators, functions with VRI and PDP1 to modulate the circadian period and rhythm strength. Knocking down tara reduces rhythm amplitude and can shorten the period length, while overexpressing TARA lengthens the circadian period. Additionally, tara mutants exhibit reduced rhythmicity and lower expression of the PDF neuropeptide. We find that TARA can form a physical complex with VRI and PDP1, enhancing their repressor and activator functions, respectively. The conserved SERTA domain of TARA is required to regulate the transcriptional activity of VRI and PDP1, and its deletion leads to reduced locomotor rhythmicity. Consistent with TARA's role in enhancing VRI and PDP1 activity, overexpressing tara has a similar effect on the circadian period and rhythm strength as simultaneously overexpressing vri and Pdp1. Together, our results suggest that TARA modulates circadian behavior by enhancing the transcriptional activity of VRI and PDP1.
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Affiliation(s)
- Oghenerukevwe Akpoghiran
- Department of Neuroscience, the Farber Institute for Neurosciences, and Synaptic Biology Center, Thomas Jefferson University, Philadelphia, USA. 19107
| | - Dinis J.S. Afonso
- Department of Neuroscience, the Farber Institute for Neurosciences, and Synaptic Biology Center, Thomas Jefferson University, Philadelphia, USA. 19107
| | - Yanan Zhang
- Department of Neuroscience, the Farber Institute for Neurosciences, and Synaptic Biology Center, Thomas Jefferson University, Philadelphia, USA. 19107
| | - Kyunghee Koh
- Department of Neuroscience, the Farber Institute for Neurosciences, and Synaptic Biology Center, Thomas Jefferson University, Philadelphia, USA. 19107
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5
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Souto-Maior C, Serrano Negron YL, Harbison ST. Nonlinear expression patterns and multiple shifts in gene network interactions underlie robust phenotypic change in Drosophila melanogaster selected for night sleep duration. PLoS Comput Biol 2023; 19:e1011389. [PMID: 37561813 PMCID: PMC10443883 DOI: 10.1371/journal.pcbi.1011389] [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: 02/15/2023] [Revised: 08/22/2023] [Accepted: 07/25/2023] [Indexed: 08/12/2023] Open
Abstract
All but the simplest phenotypes are believed to result from interactions between two or more genes forming complex networks of gene regulation. Sleep is a complex trait known to depend on the system of feedback loops of the circadian clock, and on many other genes; however, the main components regulating the phenotype and how they interact remain an unsolved puzzle. Genomic and transcriptomic data may well provide part of the answer, but a full account requires a suitable quantitative framework. Here we conducted an artificial selection experiment for sleep duration with RNA-seq data acquired each generation. The phenotypic results are robust across replicates and previous experiments, and the transcription data provides a high-resolution, time-course data set for the evolution of sleep-related gene expression. In addition to a Hierarchical Generalized Linear Model analysis of differential expression that accounts for experimental replicates we develop a flexible Gaussian Process model that estimates interactions between genes. 145 gene pairs are found to have interactions that are different from controls. Our method appears to be not only more specific than standard correlation metrics but also more sensitive, finding correlations not significant by other methods. Statistical predictions were compared to experimental data from public databases on gene interactions. Mutations of candidate genes implicated by our results affected night sleep, and gene expression profiles largely met predicted gene-gene interactions.
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Affiliation(s)
- Caetano Souto-Maior
- Laboratory of Systems Genetics, Systems Biology Center, National Heart Lung and Blood Institute, Bethesda, Maryland, United States of America
| | - Yazmin L. Serrano Negron
- Laboratory of Systems Genetics, Systems Biology Center, National Heart Lung and Blood Institute, Bethesda, Maryland, United States of America
| | - Susan T. Harbison
- Laboratory of Systems Genetics, Systems Biology Center, National Heart Lung and Blood Institute, Bethesda, Maryland, United States of America
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6
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Hou X, Hayashi R, Itoh M, Tonoki A. Small-molecule screening in aged Drosophila identifies mGluR as a regulator of age-related sleep impairment. Sleep 2023; 46:zsad018. [PMID: 36721967 DOI: 10.1093/sleep/zsad018] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 01/22/2023] [Indexed: 02/02/2023] Open
Abstract
As a normal physiological phenomenon, aging has a significant impact on sleep. Aging leads to sleep impairment, including sleep loss, fragmented sleep, and a lower arousal threshold, leading to various diseases. Because sleep regulates memory consolidation, age-dependent sleep impairment also affects memory. However, the mechanisms underlying age-related sleep dysregulation and its impact on memory remain unclear. Using male and female Drosophila as a model, which possesses sleep characteristics similar to those of mammals and exhibits age-dependent sleep impairment, we performed small-molecule screening to identify novel regulators of age-dependent decline in sleep. The screening identified 3,3'-difluorobenzaldazine (DFB), a positive allosteric modulator of the metabotropic glutamate receptor (mGluR) 5, as a novel sleep-promoting compound in aged flies. We found that mutant flies of mGluR, a single mGluR gene in Drosophila, and decreased mGluR expression had significant impairment in sleep and memory due to olfactory conditioning. The decreased sleep phenotype in the mGluR mutants was not promoted by DFB, suggesting that the effects of DFB on age-dependent sleep impairment are dependent on mGluR. Although aging decreases the expression of mGluR and the binding scaffold proteins Homer and Shank, the transient overexpression of mGluR in neurons improves sleep in both young and aged flies. Overall, these findings indicate that age-dependent decreased expression or function of mGluR impairs sleep and memory in flies, which could lead to age-related sleep and memory impairment.
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Affiliation(s)
- Xue Hou
- Department of Biochemistry, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan
| | - Reina Hayashi
- Department of Biochemistry, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan
| | - Motoyuki Itoh
- Department of Biochemistry, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan
| | - Ayako Tonoki
- Department of Biochemistry, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan
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7
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Guzman RM, Howard ZP, Liu Z, Oliveira RD, Massa AT, Omsland A, White SN, Goodman AG. Natural genetic variation in Drosophila melanogaster reveals genes associated with Coxiella burnetii infection. Genetics 2021; 217:6117219. [PMID: 33789347 PMCID: PMC8045698 DOI: 10.1093/genetics/iyab005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 01/07/2021] [Indexed: 12/16/2022] Open
Abstract
The gram-negative bacterium Coxiella burnetii is the causative agent of Query (Q) fever in humans and coxiellosis in livestock. Host genetics are associated with C. burnetii pathogenesis both in humans and animals; however, it remains unknown if specific genes are associated with severity of infection. We employed the Drosophila Genetics Reference Panel to perform a genome-wide association study to identify host genetic variants that affect host survival to C. burnetii infection. The genome-wide association study identified 64 unique variants (P < 10−5) associated with 25 candidate genes. We examined the role each candidate gene contributes to host survival during C. burnetii infection using flies carrying a null mutation or RNAi knockdown of each candidate. We validated 15 of the 25 candidate genes using at least one method. This is the first report establishing involvement of many of these genes or their homologs with C. burnetii susceptibility in any system. Among the validated genes, FER and tara play roles in the JAK/STAT, JNK, and decapentaplegic/TGF-β signaling pathways which are components of known innate immune responses to C. burnetii infection. CG42673 and DIP-ε play roles in bacterial infection and synaptic signaling but have no previous association with C. burnetii pathogenesis. Furthermore, since the mammalian ortholog of CG13404 (PLGRKT) is an important regulator of macrophage function, CG13404 could play a role in host susceptibility to C. burnetii through hemocyte regulation. These insights provide a foundation for further investigation regarding the genetics of C. burnetii susceptibility across a wide variety of hosts.
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Affiliation(s)
- Rosa M Guzman
- School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA
| | - Zachary P Howard
- School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA
| | - Ziying Liu
- School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA
| | - Ryan D Oliveira
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA
| | - Alisha T Massa
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA
| | - Anders Omsland
- Paul G. Allen School for Global Animal Health, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA
| | - Stephen N White
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA.,USDA-ARS Animal Disease Research, Pullman, WA 99164, USA.,Center for Reproductive Biology, Washington State University, Pullman, WA 99164, USA
| | - Alan G Goodman
- School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA.,Paul G. Allen School for Global Animal Health, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA
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8
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Öztürk-Çolak A, Inami S, Buchler JR, McClanahan PD, Cruz A, Fang-Yen C, Koh K. Sleep Induction by Mechanosensory Stimulation in Drosophila. Cell Rep 2020; 33:108462. [PMID: 33264620 PMCID: PMC7735403 DOI: 10.1016/j.celrep.2020.108462] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 09/11/2020] [Accepted: 11/10/2020] [Indexed: 12/11/2022] Open
Abstract
People tend to fall asleep when gently rocked or vibrated. Experimental studies have shown that rocking promotes sleep in humans and mice. However, the mechanisms underlying the phenomenon are not well understood. A habituation model proposes that habituation, a form of non-associative learning, mediates sleep induction by monotonous stimulation. Here, we show that gentle vibration promotes sleep in Drosophila in part through habituation. Vibration-induced sleep (VIS) leads to increased homeostatic sleep credit and reduced arousability, and can be suppressed by heightened arousal or reduced GABA signaling. Multiple mechanosensory organs mediate VIS, and the magnitude of VIS depends on vibration frequency and genetic background. Sleep induction improves over successive blocks of vibration. Furthermore, training with continuous vibration does not generalize to intermittent vibration, demonstrating stimulus specificity, a characteristic of habituation. Our findings suggest that habituation plays a significant role in sleep induction by vibration. Öztürk-Çolak et al. demonstrate that gentle vibration induces sleep in Drosophila. The authors show that sleep induction improves over multiple vibration sessions, which suggests that habituation, a form of simple learning, plays a significant role in vibration-induced sleep.
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Affiliation(s)
- Arzu Öztürk-Çolak
- Department of Neuroscience, Jefferson Center for Synaptic Biology, and the Farber Institute for Neurosciences, Thomas Jefferson University, Philadelphia, PA 19106, USA
| | - Sho Inami
- Department of Neuroscience, Jefferson Center for Synaptic Biology, and the Farber Institute for Neurosciences, Thomas Jefferson University, Philadelphia, PA 19106, USA
| | - Joseph R Buchler
- Department of Neuroscience, Jefferson Center for Synaptic Biology, and the Farber Institute for Neurosciences, Thomas Jefferson University, Philadelphia, PA 19106, USA
| | - Patrick D McClanahan
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Andri Cruz
- Department of Neuroscience, Jefferson Center for Synaptic Biology, and the Farber Institute for Neurosciences, Thomas Jefferson University, Philadelphia, PA 19106, USA
| | - Christopher Fang-Yen
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kyunghee Koh
- Department of Neuroscience, Jefferson Center for Synaptic Biology, and the Farber Institute for Neurosciences, Thomas Jefferson University, Philadelphia, PA 19106, USA.
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9
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Vaccaro A, Kaplan Dor Y, Nambara K, Pollina EA, Lin C, Greenberg ME, Rogulja D. Sleep Loss Can Cause Death through Accumulation of Reactive Oxygen Species in the Gut. Cell 2020; 181:1307-1328.e15. [PMID: 32502393 DOI: 10.1016/j.cell.2020.04.049] [Citation(s) in RCA: 225] [Impact Index Per Article: 56.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 01/15/2020] [Accepted: 04/24/2020] [Indexed: 02/06/2023]
Abstract
The view that sleep is essential for survival is supported by the ubiquity of this behavior, the apparent existence of sleep-like states in the earliest animals, and the fact that severe sleep loss can be lethal. The cause of this lethality is unknown. Here we show, using flies and mice, that sleep deprivation leads to accumulation of reactive oxygen species (ROS) and consequent oxidative stress, specifically in the gut. ROS are not just correlates of sleep deprivation but drivers of death: their neutralization prevents oxidative stress and allows flies to have a normal lifespan with little to no sleep. The rescue can be achieved with oral antioxidant compounds or with gut-targeted transgenic expression of antioxidant enzymes. We conclude that death upon severe sleep restriction can be caused by oxidative stress, that the gut is central in this process, and that survival without sleep is possible when ROS accumulation is prevented. VIDEO ABSTRACT.
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Affiliation(s)
- Alexandra Vaccaro
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Yosef Kaplan Dor
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Keishi Nambara
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | | | - Cindy Lin
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | | | - Dragana Rogulja
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
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10
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FUNATO H. Forward genetic approach for behavioral neuroscience using animal models. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2020; 96:10-31. [PMID: 31932526 PMCID: PMC6974404 DOI: 10.2183/pjab.96.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 10/18/2019] [Indexed: 06/10/2023]
Abstract
Forward genetics is a powerful approach to understand the molecular basis of animal behaviors. Fruit flies were the first animal to which this genetic approach was applied systematically and have provided major discoveries on behaviors including sexual, learning, circadian, and sleep-like behaviors. The development of different classes of model organism such as nematodes, zebrafish, and mice has enabled genetic research to be conducted using more-suitable organisms. The unprecedented success of forward genetic approaches was the identification of the transcription-translation negative feedback loop composed of clock genes as a fundamental and conserved mechanism of circadian rhythm. This approach has now expanded to sleep/wakefulness in mice. A conventional strategy such as dominant and recessive screenings can be modified with advances in DNA sequencing and genome editing technologies.
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Affiliation(s)
- Hiromasa FUNATO
- Department of Anatomy, Faculty of Medicine, Toho University, Tokyo, Japan
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Ibaraki, Japan
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11
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Toda H, Williams JA, Gulledge M, Sehgal A. A sleep-inducing gene, nemuri, links sleep and immune function in Drosophila. Science 2019; 363:509-515. [PMID: 30705188 PMCID: PMC6505470 DOI: 10.1126/science.aat1650] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 06/29/2018] [Accepted: 11/26/2018] [Indexed: 12/19/2022]
Abstract
Sleep remains a major mystery of biology. In particular, little is known about the mechanisms that account for the drive to sleep. In an unbiased screen of more than 12,000 Drosophila lines, we identified a single gene, nemuri, that induces sleep. The NEMURI protein is an antimicrobial peptide that can be secreted ectopically to drive prolonged sleep (with resistance to arousal) and to promote survival after infection. Loss of nemuri increased arousability during daily sleep and attenuated the acute increase in sleep induced by sleep deprivation or bacterial infection. Conditions that increase sleep drive induced expression of nemuri in a small number of fly brain neurons and targeted it to the sleep-promoting, dorsal fan-shaped body. We propose that NEMURI is a bona fide sleep homeostasis factor that is particularly important under conditions of high sleep need; because these conditions include sickness, our findings provide a link between sleep and immune function.
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Affiliation(s)
| | | | - Michael Gulledge
- Howard Hughes Medical Institute, Chronobiology Program, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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12
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Dilley LC, Vigderman A, Williams CE, Kayser MS. Behavioral and genetic features of sleep ontogeny in Drosophila. Sleep 2019; 41:4994190. [PMID: 29746663 DOI: 10.1093/sleep/zsy086] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Indexed: 11/12/2022] Open
Abstract
The fruit fly Drosophila melanogaster, like most organisms, exhibits increased sleep amount and depth in young compared to mature animals. While the fly has emerged as a powerful model for studying sleep during development, qualitative behavioral features of sleep ontogeny and its genetic control are poorly understood. Here we find that, in addition to increased sleep time and intensity, young flies sleep with less place preference than mature adults, and, like mammals, exhibit more motor twitches during sleep. In addition, we show that ontogenetic changes in sleep amount, twitch, and place preference are preserved across sleep mutants with lesions in distinct molecular pathways. Our results demonstrate that sleep ontogeny is characterized by multifaceted behavioral changes, including quantitative and qualitative alterations to sleep as animals mature. Further, the preservation of sleep ontogenetic changes despite mutations that alter sleep time suggests independent genetic control mechanisms for sleep maturation.
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Affiliation(s)
- Leela C Dilley
- Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA
| | - Abigail Vigderman
- Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA
| | - Charlette E Williams
- Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA
| | - Matthew S Kayser
- Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA.,Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA.,Chronobiology Program, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA.,Center for Sleep and Circadian Neurobiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA
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13
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Toda H, Shi M, Williams JA, Sehgal A. Genetic Mechanisms Underlying Sleep. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2019; 83:57-61. [PMID: 30936393 DOI: 10.1101/sqb.2018.83.037705] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Sleep is important for cognitive ability, and perturbations of sleep are associated with a myriad of brain disorders. However, how sleep promotes health and function during wake is poorly understood. To address the cellular and molecular mechanisms underlying sleep, we use the fruit fly Drosophila melanogaster as a genetic model. Forward genetic approaches in flies were critical for deciphering molecular mechanisms of the circadian clock. Using similar approaches, we and others are gaining insights into the pathways that control sleep amount.
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Affiliation(s)
- Hirofumi Toda
- Howard Hughes Medical Institute, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Mi Shi
- Howard Hughes Medical Institute, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Julie A Williams
- Howard Hughes Medical Institute, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Amita Sehgal
- Howard Hughes Medical Institute, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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14
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Parkinson's Disease is Associated with Dysregulations of a Dopamine-Modulated Gene Network Relevant to Sleep and Affective Neurobehaviors in the Striatum. Sci Rep 2019; 9:4808. [PMID: 30886221 PMCID: PMC6423036 DOI: 10.1038/s41598-019-41248-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 02/07/2019] [Indexed: 12/11/2022] Open
Abstract
In addition to the characteristic motor symptoms, Parkinson’s disease (PD) often involves a constellation of sleep and mood symptoms. However, the mechanisms underlying these comorbidities are largely unknown. We have previously reconstructed gene networks in the striatum of a population of (C57BL/6J x A/J) F2 mice and associated the networks to sleep and affective phenotypes, providing a resource for integrated analyses to investigate perturbed sleep and affective functions at the gene network level. Combining this resource with PD-relevant transcriptomic datasets from humans and mice, we identified four networks that showed elevated gene expression in PD patients, including a circadian clock and mitotic network that was altered similarly in mouse models of PD. We then utilized multiple types of omics data from public databases and linked this gene network to postsynaptic dopamine signaling in the striatum, CDK1-modulated transcriptional regulation, and the genetic susceptibility of PD. These findings suggest that dopamine deficiency, a key aspect of PD pathology, perturbs a circadian/mitotic gene network in striatal neurons. Since the normal functions of this network were relevant to sleep and affective behaviors, these findings implicate that dysregulation of functional gene networks may be involved in the emergence of non-motor symptoms in PD. Our analyses present a framework for integrating multi-omics data from diverse sources in mice and humans to reveal insights into comorbid symptoms of complex diseases.
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15
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Chen KF, Lowe S, Lamaze A, Krätschmer P, Jepson J. Neurocalcin regulates nighttime sleep and arousal in Drosophila. eLife 2019; 8:e38114. [PMID: 30865587 PMCID: PMC6415939 DOI: 10.7554/elife.38114] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 01/29/2019] [Indexed: 01/28/2023] Open
Abstract
Sleep-like states in diverse organisms can be separated into distinct stages, each with a characteristic arousal threshold. However, the molecular pathways underlying different sleep stages remain unclear. The fruit fly, Drosophila melanogaster, exhibits consolidated sleep during both day and night, with night sleep associated with higher arousal thresholds compared to day sleep. Here we identify a role for the neuronal calcium sensor protein Neurocalcin (NCA) in promoting sleep during the night but not the day by suppressing nocturnal arousal and hyperactivity. We show that both circadian and light-sensing pathways define the temporal window in which NCA promotes sleep. Furthermore, we find that NCA promotes sleep by suppressing synaptic release from a dispersed wake-promoting neural network and demonstrate that the mushroom bodies, a sleep-regulatory center, are a module within this network. Our results advance the understanding of how sleep stages are genetically defined.
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Affiliation(s)
- Ko-Fan Chen
- Department of Clinical and Experimental EpilepsyUCL Institute of NeurologyLondonUnited Kingdom
| | - Simon Lowe
- Department of Clinical and Experimental EpilepsyUCL Institute of NeurologyLondonUnited Kingdom
| | - Angélique Lamaze
- Department of Clinical and Experimental EpilepsyUCL Institute of NeurologyLondonUnited Kingdom
| | - Patrick Krätschmer
- Department of Clinical and Experimental EpilepsyUCL Institute of NeurologyLondonUnited Kingdom
| | - James Jepson
- Department of Clinical and Experimental EpilepsyUCL Institute of NeurologyLondonUnited Kingdom
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16
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Bringmann H. Genetic sleep deprivation: using sleep mutants to study sleep functions. EMBO Rep 2019; 20:embr.201846807. [PMID: 30804011 PMCID: PMC6399599 DOI: 10.15252/embr.201846807] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 11/14/2018] [Accepted: 11/23/2018] [Indexed: 01/08/2023] Open
Abstract
Sleep is a fundamental conserved physiological state in animals and humans. It may serve multiple functions, ranging from energy conservation to higher brain operation. Understanding sleep functions and the underlying mechanisms requires the study of sleeplessness and its consequences. The traditional approach to remove sleep is sleep deprivation (SD) by sensory stimulation. However, stimulation-induced SD can be stressful and can cause non-specific side effects. An emerging alternative method is "genetic SD", which removes sleep using genetics or optogenetics. Sleep requires sleep-active neurons and their regulators. Thus, genetic impairment of sleep circuits might lead to more specific and comprehensive sleep loss. Here, I discuss the advantages and limits of genetic SD in key genetic sleep model animals: rodents, zebrafish, fruit flies and roundworms, and how the study of genetic SD alters our view of sleep functions. Genetic SD typically causes less severe phenotypes compared with stimulation-induced SD, suggesting that sensory stimulation-induced SD may have overestimated the role of sleep, calling for a re-investigation of sleep functions.
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Affiliation(s)
- Henrik Bringmann
- Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
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17
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Abstract
The functions of sleep remain a mystery. Yet they must be important since sleep is highly conserved, and its chronic disruption is associated with various metabolic, psychiatric, and neurodegenerative disorders. This review will cover our evolving understanding of the mechanisms by which sleep is controlled and the complex relationship between sleep and disease states.
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Affiliation(s)
- William J Joiner
- Department of Pharmacology, Biomedical Sciences Graduate Program, Neurosciences Graduate Program, and Center for Circadian Biology, University of California San Diego , La Jolla, California
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18
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Control of Sleep Onset by Shal/K v4 Channels in Drosophila Circadian Neurons. J Neurosci 2018; 38:9059-9071. [PMID: 30185460 DOI: 10.1523/jneurosci.0777-18.2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Revised: 08/25/2018] [Accepted: 08/29/2018] [Indexed: 11/21/2022] Open
Abstract
Sleep is highly conserved across animal species. Both wake- and sleep-promoting neurons are implicated in the regulation of wake-sleep transition at dusk in Drosophila However, little is known about how they cooperate and whether they act via different mechanisms. Here, we demonstrated that in female Drosophila, sleep onset was specifically delayed by blocking the Shaker cognate L channels [Shal; also known as voltage-gated K+ channel 4 (Kv4)] in wake-promoting cells, including large ventral lateral neurons (l-LNvs) and pars intercerebralis (PI), but not in sleep-promoting dorsal neurons (DN1s). Delayed sleep onset was also observed in males by blocking Kv4 activity in wake-promoting neurons. Electrophysiological recordings show that Kv4 channels contribute A-type currents in LNvs and PI cells, but are much less conspicuous in DN1s. Interestingly, blocking Kv4 in wake-promoting neurons preferentially increased firing rates at dusk ∼ZT13, when the resting membrane potentials and firing rates were at lower levels. Furthermore, pigment-dispersing factor (PDF) is essential for the regulation of sleep onset by Kv4 in l-LNvs, and downregulation of PDF receptor (PDFR) in PI neurons advanced sleep onset, indicating Kv4 controls sleep onset via regulating PDF/PDFR signaling in wake-promoting neurons. We propose that Kv4 acts as a sleep onset controller by suppressing membrane excitability in a clock-dependent manner to balance the wake-sleep transition at dusk. Our results have important implications for the understanding and treatment of sleep disorders such as insomnia.SIGNIFICANCE STATEMENT The mechanisms by which our brains reversibly switch from waking to sleep state remain an unanswered and intriguing question in biological research. In this study, we identified that Shal/Kv4, a well known voltage-gated K+ channel, acts as a controller of wake-sleep transition at dusk in Drosophila circadian neurons. We find that interference of Kv4 function with a dominant-negative form (DNKv4) in subsets of circadian neurons specifically disrupts sleep onset at dusk, although Kv4 itself does not exhibit circadian oscillation. Kv4 preferentially downregulates neuronal firings at ZT9-ZT17, supporting that it plays an essential role in wake-sleep transition at dusk. Our findings may help understand and eventually treat sleep disorders such as insomnia.
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Ly S, Pack AI, Naidoo N. The neurobiological basis of sleep: Insights from Drosophila. Neurosci Biobehav Rev 2018; 87:67-86. [PMID: 29391183 PMCID: PMC5845852 DOI: 10.1016/j.neubiorev.2018.01.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 01/22/2018] [Accepted: 01/24/2018] [Indexed: 12/12/2022]
Abstract
Sleep is a biological enigma that has raised numerous questions about the inner workings of the brain. The fundamental question of why our nervous systems have evolved to require sleep remains a topic of ongoing scientific deliberation. This question is largely being addressed by research using animal models of sleep. Drosophila melanogaster, also known as the common fruit fly, exhibits a sleep state that shares common features with many other species. Drosophila sleep studies have unearthed an immense wealth of knowledge about the neuroscience of sleep. Given the breadth of findings published on Drosophila sleep, it is important to consider how all of this information might come together to generate a more holistic understanding of sleep. This review provides a comprehensive summary of the neurobiology of Drosophila sleep and explores the broader insights and implications of how sleep is regulated across species and why it is necessary for the brain.
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Affiliation(s)
- Sarah Ly
- Center for Sleep and Circadian Neurobiology, 125 South 31st St., Philadelphia, PA, 19104-3403, United States.
| | - Allan I Pack
- Center for Sleep and Circadian Neurobiology, 125 South 31st St., Philadelphia, PA, 19104-3403, United States; Division of Sleep Medicine/Department of Medicine, University of Pennsylvania Perelman School of Medicine, 125 South 31st St., Philadelphia, PA, 19104-3403, United States
| | - Nirinjini Naidoo
- Center for Sleep and Circadian Neurobiology, 125 South 31st St., Philadelphia, PA, 19104-3403, United States; Division of Sleep Medicine/Department of Medicine, University of Pennsylvania Perelman School of Medicine, 125 South 31st St., Philadelphia, PA, 19104-3403, United States.
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20
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Abstract
Sleep is essential for proper brain function in mammals and insects. During sleep, animals are disconnected from the external world; they show high arousal thresholds and changed brain activity. Sleep deprivation results in a sleep rebound. Research using the fruit fly, Drosophila melanogaster, has helped us understand the genetic and neuronal control of sleep. Genes involved in sleep control code for ion channels, factors influencing neurotransmission and neuromodulation, and proteins involved in the circadian clock. The neurotransmitters/neuromodulators involved in sleep control are GABA, dopamine, acetylcholine, serotonin, and several neuropeptides. Sleep is controlled by the interplay between sleep homeostasis and the circadian clock. Putative sleep-wake centers are located in higher-order brain centers that are indirectly connected to the circadian clock network. The primary function of sleep appears to be the downscaling of synapses that have been built up during wakefulness. Thus, brain homeostasis is maintained and learning and memory are assured.
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Affiliation(s)
- Charlotte Helfrich-Förster
- Neurobiology and Genetics, Theodor-Boveri-Institute, Biocenter, University of Würzburg, 97074 Würzburg, Germany;
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21
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Qian Y, Cao Y, Deng B, Yang G, Li J, Xu R, Zhang D, Huang J, Rao Y. Sleep homeostasis regulated by 5HT2b receptor in a small subset of neurons in the dorsal fan-shaped body of drosophila. eLife 2017; 6:26519. [PMID: 28984573 PMCID: PMC5648528 DOI: 10.7554/elife.26519] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 10/05/2017] [Indexed: 12/14/2022] Open
Abstract
Our understanding of the molecular mechanisms underlying sleep homeostasis is limited. We have taken a systematic approach to study neural signaling by the transmitter 5-hydroxytryptamine (5-HT) in drosophila. We have generated knockout and knockin lines for Trh, the 5-HT synthesizing enzyme and all five 5-HT receptors, making it possible for us to determine their expression patterns and to investigate their functional roles. Loss of the Trh, 5HT1a or 5HT2b gene decreased sleep time whereas loss of the Trh or 5HT2b gene diminished sleep rebound after sleep deprivation. 5HT2b expression in a small subset of, probably a single pair of, neurons in the dorsal fan-shaped body (dFB) is functionally essential: elimination of the 5HT2b gene from these neurons led to loss of sleep homeostasis. Genetic ablation of 5HT2b neurons in the dFB decreased sleep and impaired sleep homeostasis. Our results have shown that serotonergic signaling in specific neurons is required for the regulation of sleep homeostasis.
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Affiliation(s)
- Yongjun Qian
- Peking-Tsinghua Center for Life Sciences, State Key Laboratory of Biomembrane and Membrane Biology, PKU-IDG/McGovern Institute For Brain Research, Beijing Advanced Innovation Center for Genomics, School of Life Sciences, Peking University, Beijing, China.,National Institute of Biological Sciences, Beijing, China
| | - Yue Cao
- Peking-Tsinghua Center for Life Sciences, State Key Laboratory of Biomembrane and Membrane Biology, PKU-IDG/McGovern Institute For Brain Research, Beijing Advanced Innovation Center for Genomics, School of Life Sciences, Peking University, Beijing, China
| | - Bowen Deng
- Peking-Tsinghua Center for Life Sciences, State Key Laboratory of Biomembrane and Membrane Biology, PKU-IDG/McGovern Institute For Brain Research, Beijing Advanced Innovation Center for Genomics, School of Life Sciences, Peking University, Beijing, China.,National Institute of Biological Sciences, Beijing, China
| | - Guang Yang
- Peking-Tsinghua Center for Life Sciences, State Key Laboratory of Biomembrane and Membrane Biology, PKU-IDG/McGovern Institute For Brain Research, Beijing Advanced Innovation Center for Genomics, School of Life Sciences, Peking University, Beijing, China
| | - Jiayun Li
- Peking-Tsinghua Center for Life Sciences, State Key Laboratory of Biomembrane and Membrane Biology, PKU-IDG/McGovern Institute For Brain Research, Beijing Advanced Innovation Center for Genomics, School of Life Sciences, Peking University, Beijing, China
| | - Rui Xu
- School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Dandan Zhang
- School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Juan Huang
- School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Yi Rao
- Peking-Tsinghua Center for Life Sciences, State Key Laboratory of Biomembrane and Membrane Biology, PKU-IDG/McGovern Institute For Brain Research, Beijing Advanced Innovation Center for Genomics, School of Life Sciences, Peking University, Beijing, China.,National Institute of Biological Sciences, Beijing, China
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22
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Artiushin G, Sehgal A. The Drosophila circuitry of sleep-wake regulation. Curr Opin Neurobiol 2017; 44:243-250. [PMID: 28366532 PMCID: PMC10826075 DOI: 10.1016/j.conb.2017.03.004] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2017] [Revised: 03/03/2017] [Accepted: 03/10/2017] [Indexed: 12/20/2022]
Abstract
Sleep is a deeply conserved, yet fundamentally mysterious behavioral state. Knowledge of the circuitry of sleep-wake regulation is an essential step in understanding the physiology of the sleeping brain. Recent efforts in Drosophila have revealed new populations which impact sleep, as well as provided unprecedented mechanistic and electrophysiological detail of established sleep-regulating neurons. Multiple, distributed centers of sleep-wake circuitry exist in the fly, including the mushroom bodies, central complex and the circadian clock cells. Intriguingly, certain populations have been implicated in specific roles in homeostatic rebound sleep, occurring after sleep loss. In short, our knowledge of fly sleep circuitry advances towards a greater view of brain-wide connectivity and integration of the signals and correlates of the state of sleep.
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Affiliation(s)
- Gregory Artiushin
- Howard Hughes Medical Institute, Chronobiology Program, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Amita Sehgal
- Howard Hughes Medical Institute, Chronobiology Program, University of Pennsylvania, Philadelphia, PA 19104, USA.
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23
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Circadian Rhythms and Sleep in Drosophila melanogaster. Genetics 2017; 205:1373-1397. [PMID: 28360128 DOI: 10.1534/genetics.115.185157] [Citation(s) in RCA: 226] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 11/17/2016] [Indexed: 02/07/2023] Open
Abstract
The advantages of the model organism Drosophila melanogaster, including low genetic redundancy, functional simplicity, and the ability to conduct large-scale genetic screens, have been essential for understanding the molecular nature of circadian (∼24 hr) rhythms, and continue to be valuable in discovering novel regulators of circadian rhythms and sleep. In this review, we discuss the current understanding of these interrelated biological processes in Drosophila and the wider implications of this research. Clock genes period and timeless were first discovered in large-scale Drosophila genetic screens developed in the 1970s. Feedback of period and timeless on their own transcription forms the core of the molecular clock, and accurately timed expression, localization, post-transcriptional modification, and function of these genes is thought to be critical for maintaining the circadian cycle. Regulators, including several phosphatases and kinases, act on different steps of this feedback loop to ensure strong and accurately timed rhythms. Approximately 150 neurons in the fly brain that contain the core components of the molecular clock act together to translate this intracellular cycling into rhythmic behavior. We discuss how different groups of clock neurons serve different functions in allowing clocks to entrain to environmental cues, driving behavioral outputs at different times of day, and allowing flexible behavioral responses in different environmental conditions. The neuropeptide PDF provides an important signal thought to synchronize clock neurons, although the details of how PDF accomplishes this function are still being explored. Secreted signals from clock neurons also influence rhythms in other tissues. SLEEP is, in part, regulated by the circadian clock, which ensures appropriate timing of sleep, but the amount and quality of sleep are also determined by other mechanisms that ensure a homeostatic balance between sleep and wake. Flies have been useful for identifying a large set of genes, molecules, and neuroanatomic loci important for regulating sleep amount. Conserved aspects of sleep regulation in flies and mammals include wake-promoting roles for catecholamine neurotransmitters and involvement of hypothalamus-like regions, although other neuroanatomic regions implicated in sleep in flies have less clear parallels. Sleep is also subject to regulation by factors such as food availability, stress, and social environment. We are beginning to understand how the identified molecules and neurons interact with each other, and with the environment, to regulate sleep. Drosophila researchers can also take advantage of increasing mechanistic understanding of other behaviors, such as learning and memory, courtship, and aggression, to understand how sleep loss impacts these behaviors. Flies thus remain a valuable tool for both discovery of novel molecules and deep mechanistic understanding of sleep and circadian rhythms.
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24
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Machado DR, Afonso DJ, Kenny AR, Öztu Rk-Çolak A, Moscato EH, Mainwaring B, Kayser M, Koh K. Identification of octopaminergic neurons that modulate sleep suppression by male sex drive. eLife 2017; 6. [PMID: 28510528 PMCID: PMC5433852 DOI: 10.7554/elife.23130] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 04/25/2017] [Indexed: 12/20/2022] Open
Abstract
Molecular and circuit mechanisms for balancing competing drives are not well understood. While circadian and homeostatic mechanisms generally ensure sufficient sleep at night, other pressing needs can overcome sleep drive. Here, we demonstrate that the balance between sleep and sex drives determines whether male flies sleep or court, and identify a subset of octopaminergic neurons (MS1) that regulate sleep specifically in males. When MS1 neurons are activated, isolated males sleep less, and when MS1 neurons are silenced, the normal male sleep suppression in female presence is attenuated and mating behavior is impaired. MS1 neurons do not express the sexually dimorphic FRUITLESS (FRU) transcription factor, but form male-specific contacts with FRU-expressing neurons; calcium imaging experiments reveal bidirectional functional connectivity between MS1 and FRU neurons. We propose octopaminergic MS1 neurons interact with the FRU network to mediate sleep suppression by male sex drive.
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Affiliation(s)
- Daniel R Machado
- Department of Neuroscience, the Farber Institute for Neurosciences, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, United States.,Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal
| | - Dinis Js Afonso
- Department of Neuroscience, the Farber Institute for Neurosciences, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, United States.,Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal
| | - Alexandra R Kenny
- Department of Neuroscience, the Farber Institute for Neurosciences, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, United States
| | - Arzu Öztu Rk-Çolak
- Department of Neuroscience, the Farber Institute for Neurosciences, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, United States
| | - Emilia H Moscato
- Departments of Psychiatry and Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, United States
| | - Benjamin Mainwaring
- Departments of Psychiatry and Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, United States
| | - Matthew Kayser
- Departments of Psychiatry and Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, United States
| | - Kyunghee Koh
- Department of Neuroscience, the Farber Institute for Neurosciences, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, United States
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25
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Genes and neural circuits for sleep of the fruit fly. Neurosci Res 2017; 118:82-91. [DOI: 10.1016/j.neures.2017.04.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 03/29/2017] [Accepted: 03/29/2017] [Indexed: 02/07/2023]
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26
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Abstract
Sleep is essential for health and cognition, but the molecular and neural mechanisms of sleep regulation are not well understood. We recently reported the identification of TARANIS (TARA) as a sleep-promoting factor that acts in a previously unknown arousal center in Drosophila. tara mutants exhibit a dose-dependent reduction in sleep amount of up to ∼60%. TARA and its mammalian homologs, the Trip-Br (Transcriptional Regulators Interacting with PHD zinc fingers and/or Bromodomains) family of proteins, are primarily known as transcriptional coregulators involved in cell cycle progression, and contain a conserved Cyclin-A (CycA) binding homology domain. We found that tara and CycA synergistically promote sleep, and CycA levels are reduced in tara mutants. Additional data demonstrated that Cyclin-dependent kinase 1 (Cdk1) antagonizes tara and CycA to promote wakefulness. Moreover, we identified a subset of CycA expressing neurons in the pars lateralis, a brain region proposed to be analogous to the mammalian hypothalamus, as an arousal center. In this Extra View article, we report further characterization of tara mutants and provide an extended discussion of our findings and future directions within the framework of a working model, in which a network of cell cycle genes, tara, CycA, and Cdk1, interact in an arousal center to regulate sleep.
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Affiliation(s)
- Dinis J S Afonso
- a Department of Neuroscience ; the Farber Institute for Neurosciences; and Kimmel Cancer Center; Thomas Jefferson University ; Philadelphia , PA USA.,b Life and Health Sciences Research Institute (ICVS); School of Health Sciences; University of Minho ; 4710-057 Braga , Portugal.,c ICVS/3B's; PT Government Associate Laboratory ; 4710-057 Braga/Guimarães ; Portugal
| | - Daniel R Machado
- a Department of Neuroscience ; the Farber Institute for Neurosciences; and Kimmel Cancer Center; Thomas Jefferson University ; Philadelphia , PA USA.,b Life and Health Sciences Research Institute (ICVS); School of Health Sciences; University of Minho ; 4710-057 Braga , Portugal.,c ICVS/3B's; PT Government Associate Laboratory ; 4710-057 Braga/Guimarães ; Portugal
| | - Kyunghee Koh
- a Department of Neuroscience ; the Farber Institute for Neurosciences; and Kimmel Cancer Center; Thomas Jefferson University ; Philadelphia , PA USA
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27
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Li Q, Stavropoulos N. Evaluation of Ligand-Inducible Expression Systems for Conditional Neuronal Manipulations of Sleep in Drosophila. G3 (BETHESDA, MD.) 2016; 6:3351-3359. [PMID: 27558667 PMCID: PMC5068954 DOI: 10.1534/g3.116.034132] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 08/19/2016] [Indexed: 01/07/2023]
Abstract
Drosophila melanogaster is a powerful model organism for dissecting the molecular mechanisms that regulate sleep, and numerous studies in the fly have identified genes that impact sleep-wake cycles. Conditional genetic analysis is essential to distinguish the mechanisms by which these genes impact sleep: some genes might exert their effects developmentally, for instance by directing the assembly of neuronal circuits that regulate sleep; other genes may regulate sleep in adulthood; and yet other genes might influence sleep by both developmental and adult mechanisms. Here we have assessed two ligand-inducible expression systems, Geneswitch and the Q-system, for conditional and neuronally restricted manipulations of sleep in Drosophila While adult-specific induction of a neuronally expressed Geneswitch transgene (elav-GS) is compatible with studies of sleep as shown previously, developmental induction of elav-GS strongly and nonspecifically perturbs sleep in adults. The alterations of sleep in elav-GS animals occur at low doses of Geneswitch agonist and in the presence of transgenes unrelated to sleep, such as UAS-CD8-GFP Furthermore, developmental elav-GS induction is toxic and reduces brood size, indicating multiple adverse effects of neuronal Geneswitch activation. In contrast, the transgenes and ligand of the Q-system do not significantly impact sleep-wake cycles when used for constitutive, developmental, or adult-specific neuronal induction. The nonspecific effects of developmental elav-GS activation on sleep indicate that such manipulations require cautious interpretation, and suggest that the Q-system or other strategies may be more suitable for conditional genetic analysis of sleep and other behaviors in Drosophila.
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Affiliation(s)
- Qiuling Li
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University School of Medicine, New York 10016
| | - Nicholas Stavropoulos
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University School of Medicine, New York 10016
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28
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Song Q, Feng G, Huang Z, Chen X, Chen Z, Ping Y. Aberrant Axonal Arborization of PDF Neurons Induced by Aβ42-Mediated JNK Activation Underlies Sleep Disturbance in an Alzheimer's Model. Mol Neurobiol 2016; 54:6317-6328. [PMID: 27718103 DOI: 10.1007/s12035-016-0165-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 09/27/2016] [Indexed: 12/15/2022]
Abstract
Impaired sleep patterns are common symptoms of Alzheimer's disease (AD). Cellular mechanisms underlying sleep disturbance in AD remain largely unknown. Here, using a Drosophila Aβ42 AD model, we show that Aβ42 markedly decreases sleep in a large population, which is accompanied with postdevelopmental axonal arborization of wake-promoting pigment-dispersing factor (PDF) neurons. The arborization is mediated in part via JNK activation and can be reversed by decreasing JNK signaling activity. Axonal arborization and impaired sleep are correlated in Aβ42 and JNK kinase hemipterous mutant flies. Image reconstruction revealed that these aberrant fibers preferentially project to pars intercerebralis (PI), a fly brain region analogous to the mammalian hypothalamus. Moreover, PDF signaling in PI neurons was found to modulate sleep/wake activities, suggesting that excessive release of PDF by these aberrant fibers may lead to the impaired sleep in Aβ42 flies. Finally, inhibition of JNK activation in Aβ42 flies restores nighttime sleep loss, decreases Aβ42 accumulation, and attenuates neurodegeneration. These data provide a new mechanism by which sleep disturbance could be induced by Aβ42 burden, a key initiator of a complex pathogenic cascade in AD.
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Affiliation(s)
- Qian Song
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, China.,Shanghai Key Laboratory of Psychotic Disorders (No.13dz2260500), Shanghai Mental Health Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200030, China
| | - Ge Feng
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Zehua Huang
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, China.,School of Medicine, Shanghai Jiao Tong University, Shanghai, 200025, China
| | - Xiaoman Chen
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, China.,School of Medicine, Shanghai Jiao Tong University, Shanghai, 200025, China
| | - Zhaohuan Chen
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, China.,School of Medicine, Shanghai Jiao Tong University, Shanghai, 200025, China.,Institute of Systems Biomedicine, Collaborative Innovation Center of Systems Biomedicine, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Yong Ping
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, China. .,Shanghai Key Laboratory of Psychotic Disorders (No.13dz2260500), Shanghai Mental Health Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200030, China.
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29
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Abstract
Sleep disorders in humans are increasingly appreciated to be not only widespread but also detrimental to multiple facets of physical and mental health. Recent work has begun to shed light on the mechanistic basis of sleep disorders like insomnia, restless legs syndrome, narcolepsy, and a host of others, but a more detailed genetic and molecular understanding of how sleep goes awry is lacking. Over the past 15 years, studies in Drosophila have yielded new insights into basic questions regarding sleep function and regulation. More recently, powerful genetic approaches in the fly have been applied toward studying primary human sleep disorders and other disease states associated with dysregulated sleep. In this review, we discuss the contribution of Drosophila to the landscape of sleep biology, examining not only fundamental advances in sleep neurobiology but also how flies have begun to inform pathological sleep states in humans.
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Dubowy C, Moravcevic K, Yue Z, Wan JY, Van Dongen HP, Sehgal A. Genetic Dissociation of Daily Sleep and Sleep Following Thermogenetic Sleep Deprivation in Drosophila. Sleep 2016; 39:1083-95. [PMID: 26951392 PMCID: PMC4835307 DOI: 10.5665/sleep.5760] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 01/11/2016] [Indexed: 12/23/2022] Open
Abstract
STUDY OBJECTIVES Sleep rebound-the increase in sleep that follows sleep deprivation-is a hallmark of homeostatic sleep regulation that is conserved across the animal kingdom. However, both the mechanisms that underlie sleep rebound and its relationship to habitual daily sleep remain unclear. To address this, we developed an efficient thermogenetic method of inducing sleep deprivation in Drosophila that produces a substantial rebound, and applied the newly developed method to assess sleep rebound in a screen of 1,741 mutated lines. We used data generated by this screen to identify lines with reduced sleep rebound following thermogenetic sleep deprivation, and to probe the relationship between habitual sleep amount and sleep following thermogenetic sleep deprivation in Drosophila. METHODS To develop a thermogenetic method of sleep deprivation suitable for screening, we thermogenetically stimulated different populations of wake-promoting neurons labeled by Gal4 drivers. Sleep rebound following thermogenetically-induced wakefulness varies across the different sets of wake-promoting neurons that were stimulated, from very little to quite substantial. Thermogenetic activation of neurons marked by the c584-Gal4 driver produces both strong sleep loss and a substantial rebound that is more consistent within genotypes than rebound following mechanical or caffeine-induced sleep deprivation. We therefore used this driver to induce sleep deprivation in a screen of 1,741 mutagenized lines generated by the Drosophila Gene Disruption Project. Flies were subjected to 9 h of sleep deprivation during the dark period and released from sleep deprivation 3 h before lights-on. Recovery was measured over the 15 h following sleep deprivation. Following identification of lines with reduced sleep rebound, we characterized baseline sleep and sleep depth before and after sleep deprivation for these hits. RESULTS We identified two lines that consistently exhibit a blunted increase in the duration and depth of sleep after thermogenetic sleep deprivation. Neither of the two genotypes has reduced total baseline sleep. Statistical analysis across all screened lines shows that genotype is a strong predictor of recovery sleep, independent from effects of genotype on baseline sleep. CONCLUSIONS Our data show that rebound sleep following thermogenetic sleep deprivation can be genetically separated from sleep at baseline. This suggests that genetically controlled mechanisms of sleep regulation not manifest under undisturbed conditions contribute to sleep rebound following thermogenetic sleep deprivation.
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Affiliation(s)
- Christine Dubowy
- Cell and Molecular Biology Graduate Group, Biomedical Graduate Studies, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Katarina Moravcevic
- Department of Neuroscience, HHMI, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Zhifeng Yue
- Department of Neuroscience, HHMI, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Joy Y. Wan
- Department of Neuroscience, HHMI, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Hans P.A. Van Dongen
- Sleep and Performance Research Center and Elson S. Floyd College of Medicine, Washington State University, Spokane, WA
| | - Amita Sehgal
- Department of Neuroscience, HHMI, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
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De Nobrega AK, Lyons LC. Circadian Modulation of Alcohol-Induced Sedation and Recovery in Male and Female Drosophila. J Biol Rhythms 2016; 31:142-60. [PMID: 26833081 DOI: 10.1177/0748730415627067] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Delineating the factors that affect behavioral and neurological responses to alcohol is critical to facilitate measures for preventing or treating alcohol abuse. The high degree of conserved molecular and physiological processes makes Drosophila melanogaster a valuable model for investigating circadian interactions with alcohol-induced behaviors and examining sex-specific differences in alcohol sensitivity. We found that wild-type Drosophila exhibited rhythms in alcohol-induced sedation under light-dark and constant dark conditions with considerably greater alcohol exposure necessary to induce sedation during the late (subjective) day and peak sensitivity to alcohol occurring during the late (subjective) night. The circadian clock also modulated the recovery from alcohol-induced sedation with flies regaining motor control significantly faster during the late (subjective) day. As predicted, the circadian rhythms in sedation and recovery were absent in flies with a mutation in the circadian gene period or arrhythmic flies housed in constant light conditions. Flies lacking a functional circadian clock were more sensitive to the effects of alcohol with significantly longer recovery times. Similar to other animals and humans, Drosophila exhibit sex-specific differences in alcohol sensitivity. We investigated whether the circadian clock modulated the rhythms in the loss-of-righting reflex, alcohol-induced sedation, and recovery differently in males and females. We found that both sexes demonstrated circadian rhythms in the loss-of-righting reflex and sedation with the differences in alcohol sensitivity between males and females most pronounced during the late subjective day. Recovery of motor reflexes following alcohol sedation also exhibited circadian modulation in male and female flies, although the circadian clock did not modulate the difference in recovery times between the sexes. These studies provide a framework outlining how the circadian clock modulates alcohol-induced behaviors in Drosophila and identifies sexual dimorphisms in the circadian modulation of alcohol behaviors.
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Affiliation(s)
- Aliza K De Nobrega
- Department of Biological Science, Program in Neuroscience, Florida State University, Tallahassee, FL
| | - Lisa C Lyons
- Department of Biological Science, Program in Neuroscience, Florida State University, Tallahassee, FL
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Andretić R. Neurobiology: What Drives Flies to Sleep? Curr Biol 2015; 25:R1086-8. [PMID: 26583901 DOI: 10.1016/j.cub.2015.08.062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The number of wake-promoting neurons in the Drosophila brain is relatively small, and only some of them have the unique ability to promote robust recovery sleep following wakefulness.
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Affiliation(s)
- Rozi Andretić
- Department of Biotechnology, University of Rijeka, R. Matejcic 2, 51000 Rijeka, Croatia.
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