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Yoshii T, Saito A, Yokosako T. A four-oscillator model of seasonally adapted morning and evening activities in Drosophila melanogaster. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2024; 210:527-534. [PMID: 37217625 PMCID: PMC11226490 DOI: 10.1007/s00359-023-01639-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 05/02/2023] [Accepted: 05/10/2023] [Indexed: 05/24/2023]
Abstract
The fruit fly Drosophila melanogaster exhibits two activity peaks, one in the morning and another in the evening. Because the two peaks change phase depending on the photoperiod they are exposed to, they are convenient for studying responses of the circadian clock to seasonal changes. To explain the phase determination of the two peaks, Drosophila researchers have employed the two-oscillator model, in which two oscillators control the two peaks. The two oscillators reside in different subsets of neurons in the brain, which express clock genes, the so-called clock neurons. However, the mechanism underlying the activity of the two peaks is complex and requires a new model for mechanistic exploration. Here, we hypothesize a four-oscillator model that controls the bimodal rhythms. The four oscillators that reside in different clock neurons regulate activity in the morning and evening and sleep during the midday and at night. In this way, bimodal rhythms are formed by interactions among the four oscillators (two activity and two sleep oscillators), which may judiciously explain the flexible waveform of activity rhythms under different photoperiod conditions. Although still hypothetical, this model would provide a new perspective on the seasonal adaptation of the two activity peaks.
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Affiliation(s)
- Taishi Yoshii
- Graduate School of Natural Science and Technology, Okayama University, Tsushima-Naka 3-1, Kita-ku, Okayama, 700-8530, Japan.
| | - Aika Saito
- Graduate School of Natural Science and Technology, Okayama University, Tsushima-Naka 3-1, Kita-ku, Okayama, 700-8530, Japan
| | - Tatsuya Yokosako
- Graduate School of Natural Science and Technology, Okayama University, Tsushima-Naka 3-1, Kita-ku, Okayama, 700-8530, Japan
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2
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Brown MP, Verma S, Palmer I, Guerrero Zuniga A, Mehta A, Rosensweig C, Keles MF, Wu MN. A subclass of evening cells promotes the switch from arousal to sleep at dusk. Curr Biol 2024; 34:2186-2199.e3. [PMID: 38723636 PMCID: PMC11111347 DOI: 10.1016/j.cub.2024.04.039] [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: 08/25/2023] [Revised: 03/20/2024] [Accepted: 04/17/2024] [Indexed: 05/21/2024]
Abstract
Animals exhibit rhythmic patterns of behavior that are shaped by an internal circadian clock and the external environment. Although light intensity varies across the day, there are particularly robust differences at twilight (dawn/dusk). These periods are also associated with major changes in behavioral states, such as the transition from arousal to sleep. However, the neural mechanisms by which time and environmental conditions promote these behavioral transitions are poorly defined. Here, we show that the E1 subclass of Drosophila evening clock neurons promotes the transition from arousal to sleep at dusk. We first demonstrate that the cell-autonomous clocks of E2 neurons primarily drive and adjust the phase of evening anticipation, the canonical behavior associated with "evening" clock neurons. We next show that conditionally silencing E1 neurons causes a significant delay in sleep onset after dusk. However, rather than simply promoting sleep, activating E1 neurons produces time- and light-dependent effects on behavior. Activation of E1 neurons has no effect early in the day but then triggers arousal before dusk and induces sleep after dusk. Strikingly, these activation-induced phenotypes depend on the presence of light during the day. Despite their influence on behavior around dusk, in vivo voltage imaging of E1 neurons reveals that their spiking rate and pattern do not significantly change throughout the day. Moreover, E1-specific clock ablation has no effect on arousal or sleep. Thus, we suggest that, rather than specifying "evening" time, E1 neurons act, in concert with other rhythmic neurons, to promote behavioral transitions at dusk.
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Affiliation(s)
- Matthew P Brown
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Shubha Verma
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Isabelle Palmer
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | | | - Anuradha Mehta
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Clark Rosensweig
- Department of Neurobiology, Northwestern University, Evanston, IL 60201, USA
| | - Mehmet F Keles
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Mark N Wu
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA.
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3
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Schwarz JE, Sengupta A, Guevara C, Barber AF, Hsu CT, Zhang SL, Weljie A, Sehgal A. Age-regulated cycling metabolites are relevant for behavior. Aging Cell 2024; 23:e14082. [PMID: 38204362 PMCID: PMC11019118 DOI: 10.1111/acel.14082] [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: 08/10/2022] [Revised: 11/29/2023] [Accepted: 12/19/2023] [Indexed: 01/12/2024] Open
Abstract
Circadian cycles of sleep:wake and gene expression change with age in all organisms examined. Metabolism is also under robust circadian regulation, but little is known about how metabolic cycles change with age and whether these contribute to the regulation of behavioral cycles. To address this gap, we compared cycling of metabolites in young and old Drosophila and found major age-related variations. A significant model separated the young metabolic profiles by circadian timepoint, but could not be defined for the old metabolic profiles due to the greater variation in this dataset. Of the 159 metabolites measured in fly heads, we found 17 that cycle by JTK analysis in young flies and 17 in aged. Only four metabolites overlapped in the two groups, suggesting that cycling metabolites are distinct in young and old animals. Among our top cyclers exclusive to young flies were components of the pentose phosphate pathway (PPP). As the PPP is important for buffering reactive oxygen species, and overexpression of glucose-6-phosphate dehydrogenase (G6PD), a key component of the PPP, was previously shown to extend lifespan in Drosophila, we asked if this manipulation also affects sleep:wake cycles. We found that overexpression in circadian clock neurons decreases sleep in association with an increase in cellular calcium and mitochondrial oxidation, suggesting that altering PPP activity affects neuronal activity. Our findings elucidate the importance of metabolic regulation in maintaining patterns of neural activity, and thereby sleep:wake cycles.
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Affiliation(s)
- Jessica E. Schwarz
- Howard Hughes Medical Institute, University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
- Chronobiology and Sleep Institute, Perelman School of Medicine, University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Arjun Sengupta
- Chronobiology and Sleep Institute, Perelman School of Medicine, University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Camilo Guevara
- Chronobiology and Sleep Institute, Perelman School of Medicine, University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Annika F. Barber
- Howard Hughes Medical Institute, University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
- Chronobiology and Sleep Institute, Perelman School of Medicine, University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
- Present address:
Waksman Institute and Department of Molecular Biology and Biochemistry, RutgersThe State University of New JerseyNew BrunswickNew JerseyUSA
| | - Cynthia T. Hsu
- Howard Hughes Medical Institute, University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
- Chronobiology and Sleep Institute, Perelman School of Medicine, University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Shirley L. Zhang
- Howard Hughes Medical Institute, University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
- Chronobiology and Sleep Institute, Perelman School of Medicine, University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
- Present address:
Department of Cell BiologyEmory University School of MedicineAtlantaGeorgiaUSA
| | - Aalim Weljie
- Chronobiology and Sleep Institute, Perelman School of Medicine, University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Amita Sehgal
- Howard Hughes Medical Institute, University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
- Chronobiology and Sleep Institute, Perelman School of Medicine, University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
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4
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Dopp J, Ortega A, Davie K, Poovathingal S, Baz ES, Liu S. Single-cell transcriptomics reveals that glial cells integrate homeostatic and circadian processes to drive sleep-wake cycles. Nat Neurosci 2024; 27:359-372. [PMID: 38263460 PMCID: PMC10849968 DOI: 10.1038/s41593-023-01549-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Accepted: 12/07/2023] [Indexed: 01/25/2024]
Abstract
The sleep-wake cycle is determined by circadian and sleep homeostatic processes. However, the molecular impact of these processes and their interaction in different brain cell populations are unknown. To fill this gap, we profiled the single-cell transcriptome of adult Drosophila brains across the sleep-wake cycle and four circadian times. We show cell type-specific transcriptomic changes, with glia displaying the largest variation. Glia are also among the few cell types whose gene expression correlates with both sleep homeostat and circadian clock. The sleep-wake cycle and sleep drive level affect the expression of clock gene regulators in glia, and disrupting clock genes specifically in glia impairs homeostatic sleep rebound after sleep deprivation. These findings provide a comprehensive view of the effects of sleep homeostatic and circadian processes on distinct cell types in an entire animal brain and reveal glia as an interaction site of these two processes to determine sleep-wake dynamics.
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Affiliation(s)
- Joana Dopp
- Center for Brain & Disease Research, VIB-KU Leuven, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Leuven, Belgium
- Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Antonio Ortega
- Center for Brain & Disease Research, VIB-KU Leuven, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Leuven, Belgium
- Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Kristofer Davie
- Center for Brain & Disease Research, VIB-KU Leuven, Leuven, Belgium
- Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Suresh Poovathingal
- Center for Brain & Disease Research, VIB-KU Leuven, Leuven, Belgium
- Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - El-Sayed Baz
- Center for Brain & Disease Research, VIB-KU Leuven, Leuven, Belgium
- Leuven Brain Institute, KU Leuven, Leuven, Belgium
- Zoology Department, Faculty of Science, Suez Canal University, Ismailia, Egypt
| | - Sha Liu
- Center for Brain & Disease Research, VIB-KU Leuven, Leuven, Belgium.
- Department of Neurosciences, KU Leuven, Leuven, Belgium.
- Leuven Brain Institute, KU Leuven, Leuven, Belgium.
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5
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Tabuchi M. Dynamic neuronal instability generates synaptic plasticity and behavior: Insights from Drosophila sleep. Neurosci Res 2024; 198:1-7. [PMID: 37385545 PMCID: PMC11033711 DOI: 10.1016/j.neures.2023.06.009] [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: 03/15/2023] [Revised: 06/05/2023] [Accepted: 06/21/2023] [Indexed: 07/01/2023]
Abstract
How do neurons encode the information that underlies cognition, internal states, and behavior? This review focuses on the neural circuit mechanisms underlying sleep in Drosophila and, to illustrate the power of addressing neural coding in this system, highlights a specific circuit mediating the circadian regulation of sleep quality. This circuit exhibits circadian cycling of sleep quality, which depends solely on the pattern (not the rate) of spiking. During the night, the stability of spike waveforms enhances the reliability of spike timing in these neurons to promote sleep quality. During the day, instability of the spike waveforms leads to uncertainty of spike timing, which remarkably produces synaptic plasticity to induce arousal. Investigation of the molecular and biophysical basis of these changes was greatly facilitated by its study in Drosophila, revealing direct connections between genes, molecules, spike biophysical properties, neural codes, synaptic plasticity, and behavior. Furthermore, because these patterns of neural activity change with aging, this model system holds promise for understanding the interplay between the circadian clock, aging, and sleep quality. It is proposed here that neurophysiological investigations of the Drosophila brain present an exceptional opportunity to tackle some of the most challenging questions related to neural coding.
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Affiliation(s)
- Masashi Tabuchi
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH, United States.
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6
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Zhou F, Tichy AM, Imambocus BN, Sakharwade S, Rodriguez Jimenez FJ, González Martínez M, Jahan I, Habib M, Wilhelmy N, Burre V, Lömker T, Sauter K, Helfrich-Förster C, Pielage J, Grunwald Kadow IC, Janovjak H, Soba P. Optimized design and in vivo application of optogenetically functionalized Drosophila dopamine receptors. Nat Commun 2023; 14:8434. [PMID: 38114457 PMCID: PMC10730509 DOI: 10.1038/s41467-023-43970-0] [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: 05/18/2023] [Accepted: 11/24/2023] [Indexed: 12/21/2023] Open
Abstract
Neuromodulatory signaling via G protein-coupled receptors (GPCRs) plays a pivotal role in regulating neural network function and animal behavior. The recent development of optogenetic tools to induce G protein-mediated signaling provides the promise of acute and cell type-specific manipulation of neuromodulatory signals. However, designing and deploying optogenetically functionalized GPCRs (optoXRs) with accurate specificity and activity to mimic endogenous signaling in vivo remains challenging. Here we optimize the design of optoXRs by considering evolutionary conserved GPCR-G protein interactions and demonstrate the feasibility of this approach using two Drosophila Dopamine receptors (optoDopRs). These optoDopRs exhibit high signaling specificity and light sensitivity in vitro. In vivo, we show receptor and cell type-specific effects of dopaminergic signaling in various behaviors, including the ability of optoDopRs to rescue the loss of the endogenous receptors. This work demonstrates that optoXRs can enable optical control of neuromodulatory receptor-specific signaling in functional and behavioral studies.
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Affiliation(s)
- Fangmin Zhou
- Institute of Physiology and Pathophysiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054, Erlangen, Germany
- LIMES Institute, Department of Molecular Brain Physiology and Behavior, University of Bonn, Carl-Troll-Str. 31, 53115, Bonn, Germany
- Neuronal Patterning and Connectivity laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany
| | - Alexandra-Madelaine Tichy
- Australian Regenerative Medicine Institute (ARMI), Faculty of Medicine, Nursing and Health Sciences, Monash University, 3800, Clayton, Victoria, Australia
- European Molecular Biology Laboratory Australia (EMBL Australia), Monash University, 3800, Clayton, Victoria, Australia
| | - Bibi Nusreen Imambocus
- LIMES Institute, Department of Molecular Brain Physiology and Behavior, University of Bonn, Carl-Troll-Str. 31, 53115, Bonn, Germany
| | - Shreyas Sakharwade
- Institute of Physiology and Pathophysiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054, Erlangen, Germany
- LIMES Institute, Department of Molecular Brain Physiology and Behavior, University of Bonn, Carl-Troll-Str. 31, 53115, Bonn, Germany
| | - Francisco J Rodriguez Jimenez
- Institute of Physiology II, University Clinic Bonn (UKB), University of Bonn, 53115, Bonn, Germany
- ZIEL-Institute of Life and Health, Technical University of Munich, School of Life Sciences, 85354, Freising, Germany
| | - Marco González Martínez
- Institute of Physiology II, University Clinic Bonn (UKB), University of Bonn, 53115, Bonn, Germany
| | - Ishrat Jahan
- Institute of Physiology II, University Clinic Bonn (UKB), University of Bonn, 53115, Bonn, Germany
| | - Margarita Habib
- Neurobiology and Genetics, Biocenter, University of Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Nina Wilhelmy
- Division of Neurobiology and Zoology, RPTU University of Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Vanessa Burre
- Division of Neurobiology and Zoology, RPTU University of Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Tatjana Lömker
- Neuronal Patterning and Connectivity laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany
| | - Kathrin Sauter
- Neuronal Patterning and Connectivity laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany
| | | | - Jan Pielage
- Division of Neurobiology and Zoology, RPTU University of Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Ilona C Grunwald Kadow
- Institute of Physiology II, University Clinic Bonn (UKB), University of Bonn, 53115, Bonn, Germany
- ZIEL-Institute of Life and Health, Technical University of Munich, School of Life Sciences, 85354, Freising, Germany
| | - Harald Janovjak
- Australian Regenerative Medicine Institute (ARMI), Faculty of Medicine, Nursing and Health Sciences, Monash University, 3800, Clayton, Victoria, Australia
- European Molecular Biology Laboratory Australia (EMBL Australia), Monash University, 3800, Clayton, Victoria, Australia
- Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, 5042, Bedford Park, South Australia, Australia
| | - Peter Soba
- Institute of Physiology and Pathophysiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054, Erlangen, Germany.
- LIMES Institute, Department of Molecular Brain Physiology and Behavior, University of Bonn, Carl-Troll-Str. 31, 53115, Bonn, Germany.
- Neuronal Patterning and Connectivity laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany.
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7
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Gundermann DG, Lymer S, Blau J. A rapid and dynamic role for FMRP in the plasticity of adult neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.01.555985. [PMID: 37693612 PMCID: PMC10491314 DOI: 10.1101/2023.09.01.555985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Fragile X syndrome (FXS) is a neuro-developmental disorder caused by silencing Fmr1, which encodes the RNA-binding protein FMRP. Although Fmr1 is expressed in adult neurons, it has been challenging to separate acute from chronic effects of loss of Fmr1 in models of FXS. We have used the precision of Drosophila genetics to test if Fmr1 acutely affects adult neuronal plasticity in vivo, focusing on the s-LNv circadian pacemaker neurons that show 24 hour rhythms in structural plasticity. We found that over-expressing Fmr1 for only 4 hours blocks the activity-dependent expansion of s-LNv projections without altering the circadian clock or activity-regulated gene expression. Conversely, acutely reducing Fmr1 expression prevented s-LNv projections from retracting. One FMRP target that we identified in s-LNvs is sif, which encodes a Rac1 GEF. Our data indicate that FMRP normally reduces sif mRNA translation at dusk to reduce Rac1 activity. Overall, our data reveal a previously unappreciated rapid and direct role for FMRP in acutely regulating neuronal plasticity in adult neurons, and underscore the importance of RNA-binding proteins in this process.
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Affiliation(s)
- Daniel G Gundermann
- Department of Biology, New York University, 100 Washington Square East, New York, NY 10003, USA
| | - Seana Lymer
- Department of Biology, New York University, 100 Washington Square East, New York, NY 10003, USA
- Current address: Proteintech Genomics, 11588 Sorrento Valley Rd, San Diego, CA 92121
| | - Justin Blau
- Department of Biology, New York University, 100 Washington Square East, New York, NY 10003, USA
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, UAE
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8
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Richhariya S, Shin D, Le JQ, Rosbash M. Dissecting neuron-specific functions of circadian genes using modified cell-specific CRISPR approaches. Proc Natl Acad Sci U S A 2023; 120:e2303779120. [PMID: 37428902 PMCID: PMC10629539 DOI: 10.1073/pnas.2303779120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 06/07/2023] [Indexed: 07/12/2023] Open
Abstract
Circadian behavioral rhythms in Drosophila melanogaster are regulated by about 75 pairs of brain neurons. They all express the core clock genes but have distinct functions and gene expression profiles. To understand the importance of these distinct molecular programs, neuron-specific gene manipulations are essential. Although RNAi based methods are standard to manipulate gene expression in a cell-specific manner, they are often ineffective, especially in assays involving smaller numbers of neurons or weaker Gal4 drivers. We and others recently exploited a neuron-specific CRISPR-based method to mutagenize genes within circadian neurons. Here, we further explore this approach to mutagenize three well-studied clock genes: the transcription factor gene vrille, the photoreceptor gene Cryptochrome (cry), and the neuropeptide gene Pdf (pigment dispersing factor). The CRISPR-based strategy not only reproduced their known phenotypes but also assigned cry function for different light-mediated phenotypes to discrete, different subsets of clock neurons. We further tested two recently published methods for temporal regulation in adult neurons, inducible Cas9 and the auxin-inducible gene expression system. The results were not identical, but both approaches successfully showed that the adult-specific knockout of the neuropeptide Pdf reproduces the canonical loss-of-function mutant phenotypes. In summary, a CRISPR-based strategy is a highly effective, reliable, and general method to temporally manipulate gene function in specific adult neurons.
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9
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Sharma A, Narasimha K, Manjithaya R, Sheeba V. Restoration of Sleep and Circadian Behavior by Autophagy Modulation in Huntington's Disease. J Neurosci 2023; 43:4907-4925. [PMID: 37268416 PMCID: PMC10312063 DOI: 10.1523/jneurosci.1894-22.2023] [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: 10/07/2022] [Revised: 01/25/2023] [Accepted: 02/16/2023] [Indexed: 06/04/2023] Open
Abstract
Circadian and sleep defects are well documented in Huntington's disease (HD). Modulation of the autophagy pathway has been shown to mitigate toxic effects of mutant Huntingtin (HTT) protein. However, it is not clear whether autophagy induction can also rescue circadian and sleep defects. Using a genetic approach, we expressed human mutant HTT protein in a subset of Drosophila circadian neurons and sleep center neurons. In this context, we examined the contribution of autophagy in mitigating toxicity caused by mutant HTT protein. We found that targeted overexpression of an autophagy gene, Atg8a in male flies, induces autophagy pathway and partially rescues several HTT-induced behavioral defects, including sleep fragmentation, a key hallmark of many neurodegenerative disorders. Using cellular markers and genetic approaches, we demonstrate that indeed the autophagy pathway is involved in behavioral rescue. Surprisingly, despite behavioral rescue and evidence for the involvement of the autophagy pathway, the large visible aggregates of mutant HTT protein were not eliminated. We show that the rescue in behavior is associated with increased mutant protein aggregation and possibly enhanced output from the targeted neurons, resulting in the strengthening of downstream circuits. Overall, our study suggests that, in the presence of mutant HTT protein, Atg8a induces autophagy and improves the functioning of circadian and sleep circuits.SIGNIFICANCE STATEMENT Defects in sleep and circadian rhythms are well documented in Huntington's disease. Recent literature suggests that circadian and sleep disturbances can exacerbate neurodegenerative phenotypes. Hence, identifying potential modifiers that can improve the functioning of these circuits could greatly improve disease management. We used a genetic approach to enhance cellular proteostasis and found that overexpression of a crucial autophagy gene, Atg8a, induces the autophagy pathway in the Drosophila circadian and sleep neurons and rescues sleep and activity rhythm. We demonstrate that the Atg8a improves synaptic function of these circuits by possibly enhancing the aggregation of the mutant protein in neurons. Further, our results suggest that differences in basal levels of protein homeostatic pathways is a factor that determines selective susceptibility of neurons.
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Affiliation(s)
- Ankit Sharma
- Chronobiology and Behavioural Neurogenetics Laboratory, Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, 560064, India
| | - Kavyashree Narasimha
- Chronobiology and Behavioural Neurogenetics Laboratory, Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, 560064, India
| | - Ravi Manjithaya
- Autophagy Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, 560064, India
| | - Vasu Sheeba
- Chronobiology and Behavioural Neurogenetics Laboratory, Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, 560064, India
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10
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Roach ST, Ford MC, Simhambhatla V, Loutrianakis V, Farah H, Li Z, Periandri EM, Abdalla D, Huang I, Kalra A, Shaw PJ. Sleep deprivation, sleep fragmentation, and social jet lag increase temperature preference in Drosophila. Front Neurosci 2023; 17:1175478. [PMID: 37274220 PMCID: PMC10237294 DOI: 10.3389/fnins.2023.1175478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 05/02/2023] [Indexed: 06/06/2023] Open
Abstract
Despite the fact that sleep deprivation substantially affects the way animals regulate their body temperature, the specific mechanisms behind this phenomenon are not well understood. In both mammals and flies, neural circuits regulating sleep and thermoregulation overlap, suggesting an interdependence that may be relevant for sleep function. To investigate this relationship further, we exposed flies to 12 h of sleep deprivation, or 48 h of sleep fragmentation and evaluated temperature preference in a thermal gradient. Flies exposed to 12 h of sleep deprivation chose warmer temperatures after sleep deprivation. Importantly, sleep fragmentation, which prevents flies from entering deeper stages of sleep, but does not activate sleep homeostatic mechanisms nor induce impairments in short-term memory also resulted in flies choosing warmer temperatures. To identify the underlying neuronal circuits, we used RNAi to knock down the receptor for Pigment dispersing factor, a peptide that influences circadian rhythms, temperature preference and sleep. Expressing UAS-PdfrRNAi in subsets of clock neurons prevented sleep fragmentation from increasing temperature preference. Finally, we evaluated temperature preference after flies had undergone a social jet lag protocol which is known to disrupt clock neurons. In this protocol, flies experience a 3 h light phase delay on Friday followed by a 3 h light advance on Sunday evening. Flies exposed to social jet lag exhibited an increase in temperature preference which persisted for several days. Our findings identify specific clock neurons that are modulated by sleep disruption to increase temperature preference. Moreover, our data indicate that temperature preference may be a more sensitive indicator of sleep disruption than learning and memory.
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Affiliation(s)
- S. Tanner Roach
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, United States
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
| | - Melanie C. Ford
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
| | - Vikram Simhambhatla
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
| | - Vasilios Loutrianakis
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
| | - Hamza Farah
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
| | - Zhaoyi Li
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
| | - Erica M. Periandri
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
| | - Dina Abdalla
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
| | - Irene Huang
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
| | - Arjan Kalra
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
| | - Paul J. Shaw
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
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11
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Au DD, Liu JC, Park SJ, Nguyen TH, Dimalanta M, Foden AJ, Holmes TC. Drosophila photoreceptor systems converge in arousal neurons and confer light responsive robustness. Front Neurosci 2023; 17:1160353. [PMID: 37274190 PMCID: PMC10235467 DOI: 10.3389/fnins.2023.1160353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 05/05/2023] [Indexed: 06/06/2023] Open
Abstract
Lateral ventral neurons (LNvs) in the fly circadian neural circuit mediate behaviors other than clock resetting, including light-activated acute arousal. Converging sensory inputs often confer functional redundancy. The LNvs have three distinct light input pathways: (1) cell autonomously expressed cryptochrome (CRY), (2) rhodopsin 7 (Rh7), and (3) synaptic inputs from the eyes and other external photoreceptors that express opsins and CRY. We explored the relative photoelectrical and behavioral input contributions of these three photoreceptor systems to determine their functional impact in flies. Patch-clamp electrophysiology measuring light evoked firing frequency (FF) was performed on large LNvs (l-LNvs) in response to UV (365 nm), violet (405 nm), blue (450 nm), or red (635 nm) LED light stimulation, testing controls versus mutants that lack photoreceptor inputs gl60j, cry-null, rh7-null, and double mutant gl60j-cry-null flies. For UV, violet, and blue short wavelength light inputs, all photoreceptor mutants show significantly attenuated action potential FF responses measured in the l-LNv. In contrast, red light FF responses are only significantly attenuated in double mutant gl60j-cry-null flies. We used a light-pulse arousal assay to compare behavioral responses to UV, violet, blue and red light of control and light input mutants, measuring the awakening arousal response of flies during subjective nighttime at two different intensities to capture potential threshold differences (10 and 400 μW/cm2). The light arousal behavioral results are similar to the electrophysiological results, showing significant attenuation of behavioral light responses for mutants compared to control. These results show that the different LNv convergent photoreceptor systems are integrated and together confer functional redundancy for light evoked behavioral arousal.
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Affiliation(s)
- David D. Au
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Jenny C. Liu
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Soo Jee Park
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Thanh H. Nguyen
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Mia Dimalanta
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Alexander J. Foden
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Todd C. Holmes
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA, United States
- Center for Neural Circuit Mapping, School of Medicine, University of California, Irvine, Irvine, CA, United States
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12
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Mishra S, Sharma N, Singh SK, Lone SR. Peculiar sleep features in sympatric species may contribute to the temporal segregation. J Comp Physiol B 2023; 193:57-70. [PMID: 36271924 DOI: 10.1007/s00360-022-01463-4] [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: 12/12/2021] [Revised: 09/13/2022] [Accepted: 09/20/2022] [Indexed: 01/24/2023]
Abstract
Sleep is conserved in the animal kingdom and plays a pivotal role in the adaptation of species. Sleep in Drosophila melanogaster is defined as any continuous 5 min of quiescence, shows a prominent siesta, and consolidated nighttime sleep. Here, we analyzed the sleep of two other species D. malerkotliana (DMK) and D. ananassae (DA), and compared it with D. melanogaster (DM). The DMK males and females have siesta like DM. However, unlike DM, flies continue to sleep beyond siesta till the evening. DA has a less prominent siesta compared to DM and DMK. In the morning, DA took a longer time to respond to the lights ON and continued to sleep for at least half an hour. The nighttime sleep of the DA flies is higher than the other two species. Average length of sleep episode is three times more than that of DM and DMK with few wake episodes. Thus, the nighttime sleep of DA males and females is deep and needs exposure to more potent stimuli to wake up relative to the other two species. DA males and females show higher sleep rebound than the other two species, suggesting the robustness of sleep homeostasis. Although total sleep of DMK and DA is similar, DA is a day-active species with highly consolidated night sleep. DMK, like DM, is a crepuscular species with a midday siesta. Thus, our results suggest that temporal partitioning of sleep, in sympatric species may contribute to temporal segregation.
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Affiliation(s)
- Sukriti Mishra
- Department of Zoology, Central University of Punjab, Bathinda, Punjab, 151001, India
| | - Nisha Sharma
- Department of Zoology, Central University of Punjab, Bathinda, Punjab, 151001, India
| | - Sunil Kumar Singh
- Department of Zoology, Central University of Punjab, Bathinda, Punjab, 151001, India
| | - Shahnaz Rahman Lone
- Department of Zoology, Central University of Punjab, Bathinda, Punjab, 151001, India.
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13
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Lee H, Lim C. Circadian gating of light-induced arousal in Drosophila sleep. J Neurogenet 2022:1-11. [DOI: 10.1080/01677063.2022.2151596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Affiliation(s)
- Hoyeon Lee
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea
| | - Chunghun Lim
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea
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14
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Au DD, Liu JC, Nguyen TH, Foden AJ, Park SJ, Dimalanta M, Yu Z, Holmes TC. Nocturnal mosquito Cryptochrome 1 mediates greater electrophysiological and behavioral responses to blue light relative to diurnal mosquito Cryptochrome 1. Front Neurosci 2022; 16:1042508. [PMID: 36532283 PMCID: PMC9749892 DOI: 10.3389/fnins.2022.1042508] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 11/04/2022] [Indexed: 12/05/2022] Open
Abstract
Nocturnal Anopheles mosquitoes exhibit strong behavioral avoidance to blue-light while diurnal Aedes mosquitoes are behaviorally attracted to blue-light and a wide range of other wavelengths of light. To determine the molecular mechanism of these effects, we expressed light-sensing Anopheles gambiae (AgCRY1) and Aedes aegypti (AeCRY1) Cryptochrome 1 (CRY) genes under a crypGAL4-24 driver line in a mutant Drosophila genetic background lacking native functional CRY, then tested behavioral and electrophysiological effects of mosquito CRY expression relative to positive and negative CRY control conditions. Neither mosquito CRY stops the circadian clock as shown by robust circadian behavioral rhythmicity in constant darkness in flies expressing either AgCRY1 or AeCRY1. AgCRY1 and AeCRY1 both mediate acute increases in large ventral lateral neuronal firing rate evoked by 450 nm blue-light, corresponding to CRY's peak absorbance in its base state, indicating that both mosquito CRYs are functional, however, AgCRY1 mediates significantly stronger sustained electrophysiological light-evoked depolarization in response to blue-light relative to AeCRY1. In contrast, neither AgCRY1 nor AeCRY1 expression mediates measurable increases in large ventral lateral neuronal firing rates in response to 405 nm violet-light, the peak of the Rhodopsin-7 photoreceptor that is co-expressed in the large lateral ventral neurons. These results are consistent with the known action spectra of type 1 CRYs and lack of response in cry-null controls. AgCRY1 and AeCRY1 expressing flies show behavioral attraction to low intensity blue-light, but AgCRY1 expressing flies show behavioral avoidance to higher intensity blue-light. These results show that nocturnal and diurnal mosquito Cryptochrome 1 proteins mediate differential physiological and behavioral responses to blue-light that are consistent with species-specific mosquito behavior.
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Affiliation(s)
- David D. Au
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Jenny C. Liu
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Thanh H. Nguyen
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Alexander J. Foden
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Soo Jee Park
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Mia Dimalanta
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Zhaoxia Yu
- Department of Statistics, Donald Bren School of Information and Computer Sciences, University of California, Irvine, Irvine, CA, United States,Center for Neural Circuit Mapping, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Todd C. Holmes
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA, United States,Center for Neural Circuit Mapping, School of Medicine, University of California, Irvine, Irvine, CA, United States,*Correspondence: Todd C. Holmes,
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15
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Damulewicz M, Tyszka A, Pyza E. Light exposure during development affects physiology of adults in Drosophila melanogaster. Front Physiol 2022; 13:1008154. [PMID: 36505068 PMCID: PMC9732085 DOI: 10.3389/fphys.2022.1008154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 11/14/2022] [Indexed: 11/27/2022] Open
Abstract
Light is one of most important factors synchronizing organisms to day/night cycles in the environment. In Drosophila it is received through compound eyes, Hofbauer-Buchner eyelet, ocelli, using phospholipase C-dependent phototransduction and by deep brain photoreceptors, like Cryptochrome. Even a single light pulse during early life induces larval-time memory, which synchronizes the circadian clock and maintains daily rhythms in adult flies. In this study we investigated several processes in adult flies after maintaining their embryos, larvae and pupae in constant darkness (DD) until eclosion. We found that the lack of external light during development affects sleep time, by reduction of night sleep, and in effect shift to the daytime. However, disruption of internal CRY- dependent photoreception annuls this effect. We also observed changes in the expression of genes encoding neurotransmitters and their receptors between flies kept in different light regime. In addition, the lack of light during development results in decreasing size of mushroom bodies, involved in sleep regulation. Taking together, our results show that presence of light during early life plays a key role in brain development and affects adult behavior.
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16
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Cao H, Tang J, Liu Q, Huang J, Xu R. Autism-like behaviors regulated by the serotonin receptor 5-HT2B in the dorsal fan-shaped body neurons of Drosophila melanogaster. Eur J Med Res 2022; 27:203. [PMID: 36253869 PMCID: PMC9575255 DOI: 10.1186/s40001-022-00838-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 10/03/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairments in social interaction and repetitive stereotyped behaviors. Previous studies have reported an association of serotonin or 5-hydroxytryptamine (5-HT) with ASD, but the specific receptors and neurons by which serotonin modulates autistic behaviors have not been fully elucidated. METHODS RNAi-mediated knockdown was done to destroy the function of tryptophan hydroxylase (Trh) and all the five serotonin receptors. Given that ubiquitous knockdown of 5-HT2B showed significant defects in social behaviors, we applied the CRISPR/Cas9 system to knock out the 5-HT2B receptor gene. Social space assays and grooming assays were the major methods used to understand the role of serotonin and related specific receptors in autism-like behaviors of Drosophila melanogaster. RESULTS A close relationship was identified between serotonin and autism-like behaviors reflected by increased social space distance and high-frequency repetitive behavior in Drosophila. We further utilized the binary expression system to knock down all the five 5-HT receptors, and observed the 5-HT2B receptor as the main receptor responsible for the normal social space and repetitive behavior in Drosophila for the specific serotonin receptors underlying the regulation of these two behaviors. Our data also showed that neurons in the dorsal fan-shaped body (dFB), which expressed 5-HT2B, were functionally essential for the social behaviors of Drosophila. CONCLUSIONS Collectively, our data suggest that serotonin levels and the 5-HT2B receptor are closely related to the social interaction and repetitive behavior of Drosophila. Of all the 5 serotonin receptors, 5-HT2B receptor in dFB neurons is mainly responsible for serotonin-mediated regulation of autism-like behaviors.
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Affiliation(s)
- Haowei Cao
- Jiangsu Key Laboratory of Brain Disease and Bioinformation, Research Center for Biochemistry and Molecular Biology, Xuzhou Medical University, Xuzhou, 221004, China
| | - Junbo Tang
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100193, China
| | - Qisha Liu
- Key Laboratory of Pathogen Biology of Jiangsu Province, Department of Pathogen Biology, Nanjing Medical University, Nanjing, 211166, China
| | - Juan Huang
- Capital Medical University School of Basic Medical Sciences, Beijing, 100069, China.
| | - Rui Xu
- State Key Laboratory of Reproductive Medicine, Center of Global Health, Nanjing Medical University, Nanjing, 211166, China. .,Key Laboratory of Pathogen Biology of Jiangsu Province, Department of Pathogen Biology, Nanjing Medical University, Nanjing, 211166, China.
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17
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Au DD, Foden AJ, Park SJ, Nguyen TH, Liu JC, Tran MD, Jaime OG, Yu Z, Holmes TC. Mosquito cryptochromes expressed in Drosophila confer species-specific behavioral light responses. Curr Biol 2022; 32:3731-3744.e4. [PMID: 35914532 PMCID: PMC9810238 DOI: 10.1016/j.cub.2022.07.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 04/28/2022] [Accepted: 07/08/2022] [Indexed: 01/07/2023]
Abstract
Cryptochrome (CRY) is a short-wavelength light-sensitive photoreceptor expressed in a subset of circadian neurons and eyes in Drosophila that regulates light-evoked circadian clock resetting. Acutely, light evokes rapid electrical excitation of the ventral lateral subset of circadian neurons and confers circadian-modulated avoidance behavioral responses to short-wavelength light. Recent work shows dramatically different avoidance versus attraction behavioral responses to short-wavelength light in day-active versus night-active mosquitoes and that these behavioral responses are attenuated by CRY protein degradation by constant light exposure in mosquitoes. To determine whether CRY1s mediate species-specific coding for behavioral and electrophysiological light responses, we used an "empty neuron" approach and transgenically expressed diurnal Aedes aegypti (AeCRY1) versus nocturnal Anopheles gambiae (AgCRY1) in a cry-null Drosophila background. AeCRY1 is much less light sensitive than either AgCRY1 or DmCRY as shown by partial behavioral rhythmicity following constant light exposure. Remarkably, expression of nocturnal AgCRY1 confers low survival to constant white light as does expression of AeCRY1 to a lesser extent. AgCRY1 mediates significantly stronger electrophysiological cell-autonomous responses to 365 nm ultraviolet (UV) light relative to AeCRY1. AgCRY1 expression mediates electrophysiological sensitivity to 635 nm red light, whereas AeCRY1 does not, consistent with species-specific mosquito red light responses. AgCRY1 and DmCRY mediate intensity-dependent avoidance behavior to UV light at different light intensity thresholds, whereas AeCRY1 does not, thus mimicking mosquito and fly behaviors. These findings highlight CRY as a key non-image-forming visual photoreceptor that mediates physiological and behavioral light responses in a species-specific fashion.
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Affiliation(s)
- David D Au
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA 92697, USA
| | - Alexander J Foden
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA 92697, USA
| | - Soo Jee Park
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA 92697, USA
| | - Thanh H Nguyen
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA 92697, USA
| | - Jenny C Liu
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA 92697, USA
| | - Mary D Tran
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA 92697, USA
| | - Olga G Jaime
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA 92697, USA
| | - Zhaoxia Yu
- Department of Statistics, Donald Bren School of Information and Computer Sciences, University of California, Irvine, Irvine, CA 92697, USA; Center for Neural Circuit Mapping, University of California, Irvine, Irvine, CA 92697, USA
| | - Todd C Holmes
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA 92697, USA; Center for Neural Circuit Mapping, University of California, Irvine, Irvine, CA 92697, USA.
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18
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Dopamine and GPCR-mediated modulation of DN1 clock neurons gates the circadian timing of sleep. Proc Natl Acad Sci U S A 2022; 119:e2206066119. [PMID: 35969763 PMCID: PMC9407311 DOI: 10.1073/pnas.2206066119] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Neuromodulation is essential for adaptive animal behaviors among other physiological processes. It is essential to reliably manipulate neuromodulator pathways to understand their functions in animal physiology. In this study, we generated a CRISPR-Cas9-based guide library to target every G-Protein Coupled Receptor (GPCR) in the Drosophila genome and applied it to the well-studied clock neuron network. Notably, these GPCRs are highly enriched and differentially expressed in this small network, making it an ideal candidate to investigate their function. We cell-type specifically mutated GPCRs highly efficiently with no background gene editing detected. Applying this strategy to a specific node of the clock network revealed a role for dopamine in prolonging daytime sleep, suggesting network-specific functions of dopamine receptors in sleep-wake regulation. The metronome-like circadian regulation of sleep timing must still adapt to an uncertain environment. Recent studies in Drosophila indicate that neuromodulation not only plays a key role in clock neuron synchronization but also affects interactions between the clock network and brain sleep centers. We show here that the targets of neuromodulators, G Protein Coupled Receptors (GPCRs), are highly enriched in the fly brain circadian clock network. Single-cell sequencing indicates that they are not only enriched but also differentially expressed and contribute to clock neuron identity. We generated a comprehensive guide library to mutagenize individual GPCRs in specific neurons and verified the strategy by introducing a targeted sequencing approach. Combined with a behavioral screen, the mutagenesis strategy revealed a role of dopamine in sleep regulation by identifying two dopamine receptors and a clock neuron subpopulation that gate the timing of sleep.
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19
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Fernandez-Chiappe F, Muraro NI. Patch-Clamping Fly Brain Neurons. Cold Spring Harb Protoc 2022; 2022:Pdb.top107796. [PMID: 35798467 DOI: 10.1101/pdb.top107796] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The membrane potential of excitable cells, such as neurons and muscle cells, experiences a rich repertoire of dynamic changes mediated by an array of ligand- and voltage-gated ion channels. Central neurons, in particular, are fantastic computators of information, sensing, and integrating multiple subthreshold currents mediated by synaptic inputs and translating them into action potential patterns. Electrophysiology comprises a group of techniques that allow the direct measurement of electrical signals. There are many different electrophysiological approaches, but, because Drosophila neurons are small, the whole-cell patch-clamp technique is the only applicable method for recording electrical signals from individual central neurons. Here, we provide background on patch-clamp electrophysiology in Drosophila and introduce protocols for dissecting larval and adult brains, as well as for achieving whole-cell patch-clamp recordings of identified neuronal types. Patch clamping is a labor-intensive technique that requires a great deal of practice to become an expert; therefore, a steep learning curve should be anticipated. However, the instant gratification of neuronal spiking is an experience that we wish to share and disseminate, as many more Drosophila patch clampers are needed to study the electrical features of so many fly neuronal types unknown to date.
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Affiliation(s)
- Florencia Fernandez-Chiappe
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA-CONICET), Partner Institute of the Max Planck Society, Buenos Aires C1425FQD, Argentina
| | - Nara I Muraro
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA-CONICET), Partner Institute of the Max Planck Society, Buenos Aires C1425FQD, Argentina
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20
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Inami S, Sato T, Sakai T. Circadian Neuropeptide-Expressing Clock Neurons as Regulators of Long-Term Memory: Molecular and Cellular Perspectives. Front Mol Neurosci 2022; 15:934222. [PMID: 35909447 PMCID: PMC9326319 DOI: 10.3389/fnmol.2022.934222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 06/13/2022] [Indexed: 11/22/2022] Open
Abstract
The neuropeptide pigment-dispersing factor (Pdf) is critically involved in the regulation of circadian rhythms in various insects. The function of Pdf in circadian rhythms has been best studied in the fruitfly, i.e., Drosophila melanogaster. Drosophila Pdf is produced in a small subset of circadian clock neurons in the adult brain and functions as a circadian output signal. Recently, however, Pdf has been shown to play important roles not only in regulating circadian rhythms but also in innate and learned behaviors in Drosophila. In this mini-review, we will focus on the current findings that Pdf signaling and Pdf-producing neurons are essential for consolidating and maintaining long-term memory induced by the courtship conditioning in Drosophila and discuss the mechanisms of courtship memory processing through Pdf-producing neurons.
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Affiliation(s)
- Show Inami
- Department of Neuroscience, Farber Institute for Neurosciences, Thomas Jefferson University, Philadelphia, PA, United States
| | - Tomohito Sato
- Department of Biological Sciences, Tokyo Metropolitan University, Tokyo, Japan
| | - Takaomi Sakai
- Department of Biological Sciences, Tokyo Metropolitan University, Tokyo, Japan
- *Correspondence: Takaomi Sakai
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21
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Andreani T, Rosensweig C, Sisobhan S, Ogunlana E, Kath W, Allada R. Circadian programming of the ellipsoid body sleep homeostat in Drosophila. eLife 2022; 11:e74327. [PMID: 35735904 PMCID: PMC9270026 DOI: 10.7554/elife.74327] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 06/23/2022] [Indexed: 11/18/2022] Open
Abstract
Homeostatic and circadian processes collaborate to appropriately time and consolidate sleep and wake. To understand how these processes are integrated, we scheduled brief sleep deprivation at different times of day in Drosophila and find elevated morning rebound compared to evening. These effects depend on discrete morning and evening clock neurons, independent of their roles in circadian locomotor activity. In the R5 ellipsoid body sleep homeostat, we identified elevated morning expression of activity dependent and presynaptic gene expression as well as the presynaptic protein BRUCHPILOT consistent with regulation by clock circuits. These neurons also display elevated calcium levels in response to sleep loss in the morning, but not the evening consistent with the observed time-dependent sleep rebound. These studies reveal the circuit and molecular mechanisms by which discrete circadian clock neurons program a homeostatic sleep center.
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Affiliation(s)
- Tomas Andreani
- Department of Neurobiology, Northwestern UniversityEvanstonUnited States
| | - Clark Rosensweig
- Department of Neurobiology, Northwestern UniversityEvanstonUnited States
| | - Shiju Sisobhan
- Department of Neurobiology, Northwestern UniversityEvanstonUnited States
| | - Emmanuel Ogunlana
- Department of Neurobiology, Northwestern UniversityEvanstonUnited States
| | - William Kath
- Department of Engineering Sciences and Applied Mathematics, Northwestern UniversityEvanstonUnited States
| | - Ravi Allada
- Department of Neurobiology, Northwestern UniversityChicagoUnited States
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22
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Prakash P, Pradhan AK, Sheeba V. Hsp40 overexpression in pacemaker neurons delays circadian dysfunction in a Drosophila model of Huntington's disease. Dis Model Mech 2022; 15:275556. [PMID: 35645202 PMCID: PMC9254228 DOI: 10.1242/dmm.049447] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 05/24/2022] [Indexed: 12/13/2022] Open
Abstract
Circadian disturbances are early features of neurodegenerative diseases, including Huntington's disease (HD). Emerging evidence suggests that circadian decline feeds into neurodegenerative symptoms, exacerbating them. Therefore, we asked whether known neurotoxic modifiers can suppress circadian dysfunction. We performed a screen of neurotoxicity-modifier genes to suppress circadian behavioural arrhythmicity in a Drosophila circadian HD model. The molecular chaperones Hsp40 and HSP70 emerged as significant suppressors in the circadian context, with Hsp40 being the more potent mitigator. Upon Hsp40 overexpression in the Drosophila circadian ventrolateral neurons (LNv), the behavioural rescue was associated with neuronal rescue of loss of circadian proteins from small LNv soma. Specifically, there was a restoration of the molecular clock protein Period and its oscillations in young flies and a long-lasting rescue of the output neuropeptide Pigment dispersing factor. Significantly, there was a reduction in the expanded Huntingtin inclusion load, concomitant with the appearance of a spot-like Huntingtin form. Thus, we provide evidence implicating the neuroprotective chaperone Hsp40 in circadian rehabilitation. The involvement of molecular chaperones in circadian maintenance has broader therapeutic implications for neurodegenerative diseases. This article has an associated First Person interview with the first author of the paper. Summary: This study shows, for the first time, a neuroprotective role of chaperone Hsp40 in suppressing circadian dysfunction associated with Huntington's disease in a Drosophila model.
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Affiliation(s)
- Pavitra Prakash
- Evolutionary and Integrative Biology Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India
| | - Arpit Kumar Pradhan
- Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India
| | - Vasu Sheeba
- Evolutionary and Integrative Biology Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India.,Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India
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23
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Liu Z, Jiang L, Li C, Li C, Yang J, Yu J, Mao R, Rao Y. LKB1 Is Physiologically Required for Sleep from Drosophila melanogaster to the Mus musculus. Genetics 2022; 221:6586797. [PMID: 35579349 DOI: 10.1093/genetics/iyac082] [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: 12/13/2021] [Accepted: 05/10/2022] [Indexed: 11/14/2022] Open
Abstract
Liver Kinase B1 (LKB1) is known as a master kinase for 14 kinases related to the adenosine monophosphate (AMP)-activated protein kinase (AMPK). Two of them salt inducible kinase 3 (SIK3) and AMPKα have previously been implicated in sleep regulation. We generated loss-of-function (LOF) mutants for Lkb1 in both Drosophila and mice. Sleep, but not circadian rhythms, was reduced in Lkb1-mutant flies and in flies with neuronal deletion of Lkb1. Genetic interactions between Lkb1 and Threonine to Alanine mutation at residue 184 of AMPK in Drosophila sleep or those between Lkb1 and Threonine to Glutamic Acid mutation at residue 196 of SIK3 in Drosophila viability have been observed. Sleep was reduced in mice after virally mediated reduction of Lkb1 in the brain. Electroencephalography (EEG) analysis showed that non-rapid eye movement (NREM) sleep and sleep need were both reduced in Lkb1-mutant mice. These results indicate that LKB1 plays a physiological role in sleep regulation conserved from flies to mice.
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Affiliation(s)
- Ziyi Liu
- Peking University-Tsinghua University-National Institute of Biological Sciences Joint Graduate Program, School of Life Sciences, PKU-IDG/McGovern Institute for Brain Research, School of Chemistry and Molecular Engineering, School of Pharmaceutical Sciences, Peking University, Beijing 100871, China
- Chinese Institute for Brain Research, Beijing, China
- Capital Medical University, Beijing, China
- Changping Laboratory, Beijing, China
| | - Lifen Jiang
- Shenzhen Bay Laboratory, Institute of Molecular Physiology, Shenzhen, Guangdong, China
| | - Chaoyi Li
- Shenzhen Bay Laboratory, Institute of Molecular Physiology, Shenzhen, Guangdong, China
| | - Chengang Li
- Peking University-Tsinghua University-National Institute of Biological Sciences Joint Graduate Program, School of Life Sciences, PKU-IDG/McGovern Institute for Brain Research, School of Chemistry and Molecular Engineering, School of Pharmaceutical Sciences, Peking University, Beijing 100871, China
- Chinese Institute for Brain Research, Beijing, China
- Capital Medical University, Beijing, China
- Changping Laboratory, Beijing, China
| | - Jingqun Yang
- Peking University-Tsinghua University-National Institute of Biological Sciences Joint Graduate Program, School of Life Sciences, PKU-IDG/McGovern Institute for Brain Research, School of Chemistry and Molecular Engineering, School of Pharmaceutical Sciences, Peking University, Beijing 100871, China
- Chinese Institute for Brain Research, Beijing, China
- Capital Medical University, Beijing, China
- Changping Laboratory, Beijing, China
| | - Jianjun Yu
- Peking University-Tsinghua University-National Institute of Biological Sciences Joint Graduate Program, School of Life Sciences, PKU-IDG/McGovern Institute for Brain Research, School of Chemistry and Molecular Engineering, School of Pharmaceutical Sciences, Peking University, Beijing 100871, China
- Chinese Institute for Brain Research, Beijing, China
- Capital Medical University, Beijing, China
- Changping Laboratory, Beijing, China
| | - Renbo Mao
- Peking University-Tsinghua University-National Institute of Biological Sciences Joint Graduate Program, School of Life Sciences, PKU-IDG/McGovern Institute for Brain Research, School of Chemistry and Molecular Engineering, School of Pharmaceutical Sciences, Peking University, Beijing 100871, China
- Chinese Institute for Brain Research, Beijing, China
- Capital Medical University, Beijing, China
- Changping Laboratory, Beijing, China
| | - Yi Rao
- Peking University-Tsinghua University-National Institute of Biological Sciences Joint Graduate Program, School of Life Sciences, PKU-IDG/McGovern Institute for Brain Research, School of Chemistry and Molecular Engineering, School of Pharmaceutical Sciences, Peking University, Beijing 100871, China
- Chinese Institute for Brain Research, Beijing, China
- Capital Medical University, Beijing, China
- Changping Laboratory, Beijing, China
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24
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Morioka E, Kasuga Y, Kanda Y, Moritama S, Koizumi H, Yoshikawa T, Miura N, Ikeda M, Higashida H, Holmes TC, Ikeda M. Mitochondrial LETM1 drives ionic and molecular clock rhythms in circadian pacemaker neurons. Cell Rep 2022; 39:110787. [PMID: 35545046 DOI: 10.1016/j.celrep.2022.110787] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 03/14/2022] [Accepted: 04/14/2022] [Indexed: 11/18/2022] Open
Abstract
The mechanisms that generate robust ionic oscillation in circadian pacemaker neurons are under investigation. Here, we demonstrate critical functions of the mitochondrial cation antiporter leucine zipper-EF-hand-containing transmembrane protein 1 (LETM1), which exchanges K+/H+ in Drosophila and Ca2+/H+ in mammals, in circadian pacemaker neurons. Letm1 knockdown in Drosophila pacemaker neurons reduced circadian cytosolic H+ rhythms and prolonged nuclear PERIOD/TIMELESS expression rhythms and locomotor activity rhythms. In rat pacemaker neurons in the hypothalamic suprachiasmatic nucleus (SCN), circadian rhythms in cytosolic Ca2+ and Bmal1 transcription were dampened by Letm1 knockdown. Mitochondrial Ca2+ uptake peaks late during the day were also observed in rat SCN neurons following photolytic elevation of cytosolic Ca2+. Since cation transport by LETM1 is coupled to mitochondrial energy synthesis, we propose that LETM1 integrates metabolic, ionic, and molecular clock rhythms in the central clock system in both invertebrates and vertebrates.
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Affiliation(s)
- Eri Morioka
- Graduate School of Science and Engineering, University of Toyama, Gofuku, Toyama 930-8555, Japan
| | - Yusuke Kasuga
- Graduate School of Science and Engineering, University of Toyama, Gofuku, Toyama 930-8555, Japan
| | - Yuzuki Kanda
- Graduate School of Science and Engineering, University of Toyama, Gofuku, Toyama 930-8555, Japan
| | - Saki Moritama
- Graduate School of Science and Engineering, University of Toyama, Gofuku, Toyama 930-8555, Japan
| | - Hayato Koizumi
- Graduate School of Innovative Life Science, University of Toyama, Gofuku, Toyama 930-8555, Japan
| | - Tomoko Yoshikawa
- Organization for International Education and Exchange, University of Toyama, Toyama 930-8555, Japan
| | - Nobuhiko Miura
- Department of Health Medicine, Yokohama University of Pharmacy, Yokohama, Kanagawa 245-0061, Japan
| | - Masaaki Ikeda
- Department of Physiology, Faculty of Medicine, Saitama Medical University, Saitama 350-0495, Japan
| | - Haruhiro Higashida
- Research Center for Child Mental Development, Kanazawa University, Ishikawa 920-8640, Japan
| | - Todd C Holmes
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, CA 92697, USA
| | - Masayuki Ikeda
- Graduate School of Innovative Life Science, University of Toyama, Gofuku, Toyama 930-8555, Japan; Organization for International Education and Exchange, University of Toyama, Toyama 930-8555, Japan.
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25
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Chaturvedi R, Stork T, Yuan C, Freeman MR, Emery P. Astrocytic GABA transporter controls sleep by modulating GABAergic signaling in Drosophila circadian neurons. Curr Biol 2022; 32:1895-1908.e5. [PMID: 35303417 PMCID: PMC9090989 DOI: 10.1016/j.cub.2022.02.066] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 01/11/2022] [Accepted: 02/23/2022] [Indexed: 11/16/2022]
Abstract
A precise balance between sleep and wakefulness is essential to sustain a good quality of life and optimal brain function. GABA is known to play a key and conserved role in sleep control, and GABAergic tone should, therefore, be tightly controlled in sleep circuits. Here, we examined the role of the astrocytic GABA transporter (GAT) in sleep regulation using Drosophila melanogaster. We found that a hypomorphic gat mutation (gat33-1) increased sleep amount, decreased sleep latency, and increased sleep consolidation at night. Interestingly, sleep defects were suppressed when gat33-1 was combined with a mutation disrupting wide-awake (wake), a gene that regulates the cell-surface levels of the GABAA receptor resistance to dieldrin (RDL) in the wake-promoting large ventral lateral neurons (l-LNvs). Moreover, RNAi knockdown of rdl and its modulators dnlg4 and wake in these circadian neurons also suppressed gat33-1 sleep phenotypes. Brain immunohistochemistry showed that GAT-expressing astrocytes were located near RDL-positive l-LNv cell bodies and dendritic processes. We concluded that astrocytic GAT decreases GABAergic tone and RDL activation in arousal-promoting LNvs, thus determining proper sleep amount and quality in Drosophila.
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Affiliation(s)
- Ratna Chaturvedi
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Tobias Stork
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA; Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Chunyan Yuan
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Marc R Freeman
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA; Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Patrick Emery
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA.
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26
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Buhl E, Kim YA, Parsons T, Zhu B, Santa-Maria I, Lefort R, Hodge JJ. Effects of Eph/ephrin signalling and human Alzheimer's disease-associated EphA1 on behaviour and neurophysiology. Neurobiol Dis 2022; 170:105752. [DOI: 10.1016/j.nbd.2022.105752] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 04/09/2022] [Accepted: 05/09/2022] [Indexed: 12/13/2022] Open
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27
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Eick AK, Ogueta M, Buhl E, Hodge JJL, Stanewsky R. The opposing chloride cotransporters KCC and NKCC control locomotor activity in constant light and during long days. Curr Biol 2022; 32:1420-1428.e4. [PMID: 35303416 DOI: 10.1016/j.cub.2022.01.056] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 12/06/2021] [Accepted: 01/20/2022] [Indexed: 01/08/2023]
Abstract
Cation chloride cotransporters (CCCs) regulate intracellular chloride ion concentration ([Cl-]i) within neurons, which can reverse the direction of the neuronal response to the neurotransmitter GABA.1 Na+ K+ Cl- (NKCC) and K+ Cl- (KCC) cotransporters transport Cl- into or out of the cell, respectively. When NKCC activity dominates, the resulting high [Cl-]i can lead to an excitatory and depolarizing response of the neuron upon GABAA receptor opening, while KCC dominance has the opposite effect.1 This inhibitory-to-excitatory GABA switch has been linked to seasonal adaption of circadian clock function to changing day length,2-4 and its dysregulation is associated with neurodevelopmental disorders such as epilepsy.5-8 In Drosophila melanogaster, constant light normally disrupts circadian clock function and leads to arrhythmic behavior.9 Here, we demonstrate a function for CCCs in regulating Drosophila locomotor activity and GABA responses in circadian clock neurons because alteration of CCC expression in circadian clock neurons elicits rhythmic behavior in constant light. We observed the same effects after downregulation of the Wnk and Fray kinases, which modulate CCC activity in a [Cl-]i-dependent manner. Patch-clamp recordings from the large LNv clock neurons show that downregulation of KCC results in a more positive GABA reversal potential, while KCC overexpression has the opposite effect. Finally, KCC and NKCC downregulation reduces or increases morning behavioral activity during long photoperiods, respectively. In summary, our results support a model in which the regulation of [Cl-]i by a KCC/NKCC/Wnk/Fray feedback loop determines the response of clock neurons to GABA, which is important for adjusting behavioral activity to constant light and long-day conditions.
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Affiliation(s)
- Anna Katharina Eick
- Institute of Neuro- and Behavioral Biology, Westfälische Wilhelms University, 48149 Münster, Germany
| | - Maite Ogueta
- Institute of Neuro- and Behavioral Biology, Westfälische Wilhelms University, 48149 Münster, Germany
| | - Edgar Buhl
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol BS8 1TD, UK
| | - James J L Hodge
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol BS8 1TD, UK
| | - Ralf Stanewsky
- Institute of Neuro- and Behavioral Biology, Westfälische Wilhelms University, 48149 Münster, Germany.
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28
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Iyengar AS, Kulkarni R, Sheeba V. Under warm ambient conditions, Drosophila melanogaster suppresses nighttime activity via the neuropeptide pigment dispersing factor. GENES, BRAIN, AND BEHAVIOR 2022; 21:e12802. [PMID: 35285135 PMCID: PMC9744560 DOI: 10.1111/gbb.12802] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 02/21/2022] [Accepted: 02/21/2022] [Indexed: 11/26/2022]
Abstract
Rhythmic locomotor behaviour of flies is controlled by an endogenous time-keeping mechanism, the circadian clock, and is influenced by environmental temperatures. Flies inherently prefer cool temperatures around 25°C, and under such conditions, time their locomotor activity to occur at dawn and dusk. Under relatively warmer conditions such as 30°C, flies shift their activity into the night, advancing their morning activity bout into the early morning, before lights-ON, and delaying their evening activity into early night. The molecular basis for such temperature-dependent behavioural modulation has been associated with core circadian clock genes, but the neuronal basis is not yet clear. Under relatively cool temperatures such as 25°C, the role of the circadian pacemaker ventrolateral neurons (LNvs), along with a major neuropeptide secreted by them, pigment dispersing factor (PDF), has been showed in regulating various aspects of locomotor activity rhythms. However, the role of the LNvs and PDF in warm temperature-mediated behavioural modulation has not been explored. We show here that flies lacking proper PDF signalling or the LNvs altogether, cannot suppress their locomotor activity resulting in loss of sleep during the middle of the night, and thus describe a novel role for PDF signalling and the LNvs in behavioural modulation under warm ambient conditions. In a rapidly warming world, such behavioural plasticity may enable organisms to respond to harsh temperatures in the environment.
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Affiliation(s)
- Aishwariya Srikala Iyengar
- Chronobiology and Behavioural Neurogenetics LaboratoryNeuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific ResearchBangaloreIndia
| | - Rutvij Kulkarni
- Chronobiology and Behavioural Neurogenetics LaboratoryNeuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific ResearchBangaloreIndia
| | - Vasu Sheeba
- Chronobiology and Behavioural Neurogenetics LaboratoryNeuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific ResearchBangaloreIndia
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29
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Delfino L, Campesan S, Fedele G, Green EW, Giorgini F, Kyriacou CP, Rosato E. Visualization of Mutant Aggregates from Clock Neurons by Agarose Gel Electrophoresis (AGERA) in Drosophila melanogaster. Methods Mol Biol 2022; 2482:373-383. [PMID: 35610440 DOI: 10.1007/978-1-0716-2249-0_25] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The clock neurons of the fruit fly Drosophila melanogaster have become a useful model for expressing misfolded protein aggregates that accumulate in several human neurodegenerative diseases. One advantage of such an approach is that the behavioral effects can be readily quantified on circadian locomotor rhythms, sleep or activity levels via automated, highly reliable and objective procedures. Therefore, a rapid assay is required to visualize whether these neurons develop aggregates. Here we describe a modified immunoblot method, agarose gel electrophoresis (AGERA) that has been optimized for resolving aggregates from fly clock neurons.
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Affiliation(s)
- Laura Delfino
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
| | - Susanna Campesan
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
| | - Giorgio Fedele
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
| | - Edward W Green
- German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Flaviano Giorgini
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
| | | | - Ezio Rosato
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
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30
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Li Q, Jang H, Lim KY, Lessing A, Stavropoulos N. insomniac links the development and function of a sleep-regulatory circuit. eLife 2021; 10:65437. [PMID: 34908527 PMCID: PMC8758140 DOI: 10.7554/elife.65437] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 10/15/2021] [Indexed: 11/17/2022] Open
Abstract
Although many genes are known to influence sleep, when and how they impact sleep-regulatory circuits remain ill-defined. Here, we show that insomniac (inc), a conserved adaptor for the autism-associated Cul3 ubiquitin ligase, acts in a restricted period of neuronal development to impact sleep in adult Drosophila. The loss of inc causes structural and functional alterations within the mushroom body (MB), a center for sensory integration, associative learning, and sleep regulation. In inc mutants, MB neurons are produced in excess, develop anatomical defects that impede circuit assembly, and are unable to promote sleep when activated in adulthood. Our findings link neurogenesis and postmitotic development of sleep-regulatory neurons to their adult function and suggest that developmental perturbations of circuits that couple sensory inputs and sleep may underlie sleep dysfunction in neurodevelopmental disorders.
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Affiliation(s)
- Qiuling Li
- Neuroscience Institute, Department of Neuroscience and Physiology, New York University School of MedicineNew YorkUnited States
| | - Hyunsoo Jang
- Neuroscience Institute, Department of Neuroscience and Physiology, New York University School of MedicineNew YorkUnited States
| | - Kayla Y Lim
- Neuroscience Institute, Department of Neuroscience and Physiology, New York University School of MedicineNew YorkUnited States
| | - Alexie Lessing
- Neuroscience Institute, Department of Neuroscience and Physiology, New York University School of MedicineNew YorkUnited States
| | - Nicholas Stavropoulos
- Neuroscience Institute, Department of Neuroscience and Physiology, New York University School of MedicineNew YorkUnited States
- Waksman Institute, Rutgers UniversityPiscatawayUnited States
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31
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Hugin + neurons provide a link between sleep homeostat and circadian clock neurons. Proc Natl Acad Sci U S A 2021; 118:2111183118. [PMID: 34782479 DOI: 10.1073/pnas.2111183118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/13/2021] [Indexed: 11/18/2022] Open
Abstract
Sleep is controlled by homeostatic mechanisms, which drive sleep after wakefulness, and a circadian clock, which confers the 24-h rhythm of sleep. These processes interact with each other to control the timing of sleep in a daily cycle as well as following sleep deprivation. However, the mechanisms by which they interact are poorly understood. We show here that hugin + neurons, previously identified as neurons that function downstream of the clock to regulate rhythms of locomotor activity, are also targets of the sleep homeostat. Sleep deprivation decreases activity of hugin + neurons, likely to suppress circadian-driven activity during recovery sleep, and ablation of hugin + neurons promotes sleep increases generated by activation of the homeostatic sleep locus, the dorsal fan-shaped body (dFB). Also, mutations in peptides produced by the hugin + locus increase recovery sleep following deprivation. Transsynaptic mapping reveals that hugin + neurons feed back onto central clock neurons, which also show decreased activity upon sleep loss, in a Hugin peptide-dependent fashion. We propose that hugin + neurons integrate circadian and sleep signals to modulate circadian circuitry and regulate the timing of sleep.
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32
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Mechanosensory Stimulation via Nanchung Expressing Neurons Can Induce Daytime Sleep in Drosophila. J Neurosci 2021; 41:9403-9418. [PMID: 34635540 DOI: 10.1523/jneurosci.0400-21.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 08/31/2021] [Accepted: 09/02/2021] [Indexed: 11/21/2022] Open
Abstract
The neuronal and genetic bases of sleep, a phenomenon considered crucial for well-being of organisms, has been under investigation using the model organism Drosophila melanogaster Although sleep is a state where sensory threshold for arousal is greater, it is known that certain kinds of repetitive sensory stimuli, such as rocking, can indeed promote sleep in humans. Here we report that orbital motion-aided mechanosensory stimulation promotes sleep of male and female Drosophila, independent of the circadian clock, but controlled by the homeostatic system. Mechanosensory receptor nanchung (Nan)-expressing neurons in the chordotonal organs mediate this sleep induction: flies in which these neurons are either silenced or ablated display significantly reduced sleep induction on mechanosensory stimulation. Transient activation of the Nan-expressing neurons also enhances sleep levels, confirming the role of these neurons in sleep induction. We also reveal that certain regions of the antennal mechanosensory and motor center in the brain are involved in conveying information from the mechanosensory structures to the sleep centers. Thus, we show, for the first time, that a circadian clock-independent pathway originating from peripherally distributed mechanosensors can promote daytime sleep of flies Drosophila melanogaster SIGNIFICANCE STATEMENT Our tendency to fall asleep in moving vehicles or the practice of rocking infants to sleep suggests that slow rhythmic movement can induce sleep, although we do not understand the mechanistic basis of this phenomenon. We find that gentle orbital motion can induce behavioral quiescence even in flies, a highly genetically tractable system for sleep studies. We demonstrate that this is indeed true sleep based on its rapid reversibility by sensory stimulation, enhanced arousal threshold, and homeostatic control. Furthermore, we demonstrate that mechanosensory neurons expressing a TRPV channel nanchung, located in the antennae and chordotonal organs, mediate orbital motion-induced sleep by communicating with antennal mechanosensory motor centers, which in turn may project to sleep centers in the brain.
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33
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Decapentaplegic Acutely Defines the Connectivity of Central Pacemaker Neurons in Drosophila. J Neurosci 2021; 41:8338-8350. [PMID: 34429376 DOI: 10.1523/jneurosci.0397-21.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 07/12/2021] [Accepted: 08/11/2021] [Indexed: 11/21/2022] Open
Abstract
Rhythmic rest-activity cycles are controlled by an endogenous clock. In Drosophila, this clock resides in ∼150 neurons organized in clusters whose hierarchy changes in response to environmental conditions. The concerted activity of the circadian network is necessary for the adaptive responses to synchronizing environmental stimuli. Thus far, work was devoted to unravel the logic of the coordination of different clusters focusing on neurotransmitters and neuropeptides. We further explored communication in the adult male brain through ligands belonging to the bone morphogenetic protein (BMP) pathway. Herein we show that the lateral ventral neurons (LNvs) express the small morphogen decapentaplegic (DPP). DPP expression in the large LNvs triggered a period lengthening phenotype, the downregulation of which caused reduced rhythmicity and affected anticipation at dawn and dusk, underscoring DPP per se conveys time-of-day relevant information. Surprisingly, DPP expression in the large LNvs impaired circadian remodeling of the small LNv axonal terminals, likely through local modulation of the guanine nucleotide exchange factor Trio. These findings open the provocative possibility that the BMP pathway is recruited to strengthen/reduce the connectivity among specific clusters along the day and thus modulate the contribution of the clusters to the circadian network.SIGNIFICANCE STATEMENT The circadian clock relies on the communication between groups of so-called clock neurons to coordinate physiology and behavior to the optimal times across the day, predicting and adapting to a changing environment. The circadian network relies on neurotransmitters and neuropeptides to fine-tune connectivity among clock neurons and thus give rise to a coherent output. Herein we show that decapentaplegic, a ligand belonging to the BMP retrograde signaling pathway required for coordinated growth during development, is recruited by a group of circadian neurons in the adult brain to trigger structural remodeling of terminals on a daily basis.
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34
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Dai X, Zhou E, Yang W, Mao R, Zhang W, Rao Y. Molecular resolution of a behavioral paradox: sleep and arousal are regulated by distinct acetylcholine receptors in different neuronal types in Drosophila. Sleep 2021; 44:6119684. [PMID: 33493349 DOI: 10.1093/sleep/zsab017] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 12/21/2020] [Indexed: 02/02/2023] Open
Abstract
Sleep and arousal are both important for animals. The neurotransmitter acetylcholine (ACh) has long been found to promote both sleep and arousal in mammals, an apparent paradox which has also been found to exist in flies, causing much confusion in understanding sleep and arousal. Here, we have systematically studied all 13 ACh receptors (AChRs) in Drosophila to understand mechanisms underlying ACh function in sleep and arousal. We found that exogenous stimuli-induced arousal was decreased in nAChRα3 mutants, whereas sleep was decreased in nAChRα2 and nAChRβ2 mutants. nAChRα3 functions in dopaminergic neurons to promote exogenous stimuli-induced arousal, whereas nAChRα2 and β2 function in octopaminergic neurons to promote sleep. Our studies have revealed that a single transmitter can promote endogenous sleep and exogenous stimuli-induced arousal through distinct receptors in different types of downstream neurons.
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Affiliation(s)
- Xihuimin Dai
- PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, Beijing Advanced Innovation Center for Genomics, Peking University School of Life Sciences, Beijing, China.,Chinese Institute for Brain Research, Beijing, China.,Howard Hughes Medical Institute, Department of Biology, Brandeis University, Waltham, MA
| | - Enxing Zhou
- PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, Beijing Advanced Innovation Center for Genomics, Peking University School of Life Sciences, Beijing, China
| | - Wei Yang
- PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, Beijing Advanced Innovation Center for Genomics, Peking University School of Life Sciences, Beijing, China.,Chinese Institute for Brain Research, Beijing, China
| | - Renbo Mao
- Graduate School of Peking Union Medical College, Beijing, China.,National Institute of Biological Sciences, Beijing, China
| | - Wenxia Zhang
- PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, Beijing Advanced Innovation Center for Genomics, Peking University School of Life Sciences, Beijing, China
| | - Yi Rao
- PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, Beijing Advanced Innovation Center for Genomics, Peking University School of Life Sciences, Beijing, China.,Chinese Institute for Brain Research, Beijing, China
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35
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Nave C, Roberts L, Hwu P, Estrella JD, Vo TC, Nguyen TH, Bui TT, Rindner DJ, Pervolarakis N, Shaw PJ, Leise TL, Holmes TC. Weekend Light Shifts Evoke Persistent Drosophila Circadian Neural Network Desynchrony. J Neurosci 2021; 41:5173-5189. [PMID: 33931552 PMCID: PMC8211545 DOI: 10.1523/jneurosci.3074-19.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 04/13/2021] [Accepted: 04/15/2021] [Indexed: 11/21/2022] Open
Abstract
We developed a method for single-cell resolution longitudinal bioluminescence imaging of PERIOD (PER) protein and TIMELESS (TIM) oscillations in cultured male adult Drosophila brains that captures circadian circuit-wide cycling under simulated day/night cycles. Light input analysis confirms that CRYPTOCHROME (CRY) is the primary circadian photoreceptor and mediates clock disruption by constant light (LL), and that eye light input is redundant to CRY; 3-h light phase delays (Friday) followed by 3-h light phase advances (Monday morning) simulate the common practice of staying up later at night on weekends, sleeping in later on weekend days then returning to standard schedule Monday morning [weekend light shift (WLS)]. PER and TIM oscillations are highly synchronous across all major circadian neuronal subgroups in unshifted light schedules for 11 d. In contrast, WLS significantly dampens PER oscillator synchrony and rhythmicity in most circadian neurons during and after exposure. Lateral ventral neuron (LNv) oscillations are the first to desynchronize in WLS and the last to resynchronize in WLS. Surprisingly, the dorsal neuron group-3 (DN3s) increase their within-group synchrony in response to WLS. In vivo, WLS induces transient defects in sleep stability, learning, and memory that temporally coincide with circuit desynchrony. Our findings suggest that WLS schedules disrupt circuit-wide circadian neuronal oscillator synchrony for much of the week, thus leading to observed behavioral defects in sleep, learning, and memory.
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Affiliation(s)
- Ceazar Nave
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, California 92697
| | - Logan Roberts
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, California 92697
| | - Patrick Hwu
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, California 92697
| | - Jerson D Estrella
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, California 92697
| | - Thanh C Vo
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, California 92697
| | - Thanh H Nguyen
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, California 92697
| | - Tony Thai Bui
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, California 92697
| | - Daniel J Rindner
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, California 92697
| | - Nicholas Pervolarakis
- Center for Complex Biological Systems, University of California, Irvine, Irvine, California 92697
| | - Paul J Shaw
- Department of Anatomy and Neurobiology, Washington University in St. Louis, St. Louis, Missouri 63110
| | - Tanya L Leise
- Department of Mathematics and Statistics, Amherst College, Amherst, Massachusetts 01002
| | - Todd C Holmes
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, California 92697
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36
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Abstract
Circadian clocks are biochemical time-keeping machines that synchronize animal behavior and physiology with planetary rhythms. In Drosophila, the core components of the clock comprise a transcription/translation feedback loop and are expressed in seven neuronal clusters in the brain. Although it is increasingly evident that the clocks in each of the neuronal clusters are regulated differently, how these clocks communicate with each other across the circadian neuronal network is less clear. Here, we review the latest evidence that describes the physical connectivity of the circadian neuronal network . Using small ventral lateral neurons as a starting point, we summarize how one clock may communicate with another, highlighting the signaling pathways that are both upstream and downstream of these clocks. We propose that additional efforts are required to understand how temporal information generated in each circadian neuron is integrated across a neuronal circuit to regulate rhythmic behavior.
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Affiliation(s)
- Myra Ahmad
- Department of Pediatrics, Division of Medical Genetics, Dalhousie University, Halifax, NS, Canada
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada
| | - Wanhe Li
- Laboratory of Genetics, The Rockefeller University, New York, NY, USA
| | - Deniz Top
- Department of Pediatrics, Division of Medical Genetics, Dalhousie University, Halifax, NS, Canada
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada
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37
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Hidalgo S, Campusano JM, Hodge JJL. The Drosophila ortholog of the schizophrenia-associated CACNA1A and CACNA1B voltage-gated calcium channels regulate memory, sleep and circadian rhythms. Neurobiol Dis 2021; 155:105394. [PMID: 34015490 DOI: 10.1016/j.nbd.2021.105394] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 05/10/2021] [Accepted: 05/14/2021] [Indexed: 01/04/2023] Open
Abstract
Schizophrenia exhibits up to 80% heritability. A number of genome wide association studies (GWAS) have repeatedly shown common variants in voltage-gated calcium (Cav) channel genes CACNA1C, CACNA1I and CACNA1G have a major contribution to the risk of the disease. More recently, studies using whole exome sequencing have also found that CACNA1B (Cav2.2 N-type) deletions and rare disruptive variants in CACNA1A (Cav2.1 P/Q-type) are associated with schizophrenia. The negative symptoms of schizophrenia include behavioural defects such as impaired memory, sleep and circadian rhythms. It is not known how variants in schizophrenia-associated genes contribute to cognitive and behavioural symptoms, thus hampering the development of treatment for schizophrenia symptoms. In order to address this knowledge gap, we studied behavioural phenotypes in a number of loss of function mutants for the Drosophila ortholog of the Cav2 gene family called cacophony (cac). cac mutants showed several behavioural features including decreased night-time sleep and hyperactivity similar to those reported in human patients. The change in timing of sleep-wake cycles suggested disrupted circadian rhythms, with the loss of night-time sleep being caused by loss of cac just in the circadian clock neurons. These animals also showed a reduction in rhythmic circadian behaviour a phenotype that also could be mapped to the central clock. Furthermore, reduction of cac just in the clock resulted in a lengthening of the 24 h period. In order to understand how loss of Cav2 function may lead to cognitive deficits and underlying cellular pathophysiology we targeted loss of function of cac to the memory centre of the fly, called the mushroom bodies (MB). This manipulation was sufficient to cause reduction in both short- and intermediate-term associative memory. Memory impairment was accompanied by a decrease in Ca2+ transients in response to a depolarizing stimulus, imaged in the MB presynaptic terminals. This work shows loss of cac Cav2 channel function alone causes a number of cognitive and behavioural deficits and underlying reduced neuronal Ca2+ transients, establishing Drosophila as a high-throughput in vivo genetic model to study the Cav channel pathophysiology related to schizophrenia.
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Affiliation(s)
- Sergio Hidalgo
- School of Physiology, Pharmacology and Neuroscience, Faculty of Life Science, University of Bristol, UK; Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Chile
| | - Jorge M Campusano
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Chile
| | - James J L Hodge
- School of Physiology, Pharmacology and Neuroscience, Faculty of Life Science, University of Bristol, UK.
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38
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Abstract
Drosophila melanogaster is a powerful model organism used to study circadian rhythms, historically for elucidating the molecular basis of the clock and, more recently, for allowing for dissection of neural circuits underlying rhythmic behavior. The fly can be used to investigate the neuronal basis of complex behaviors at single-neuron resolution. Patch clamp electrophysiology permits single-neuron recording of resting membrane potential and action potential firing in response to genetic or environmental manipulations or application of drugs and neurotransmitters. Here we describe a protocol for dissecting Drosophila brains for electrophysiology, setting up and using a patch clamp system, and analyzing firing data around the circadian day and in stimulation-response experiments to test for functional neuronal connectivity in circadian circuits.
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39
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Neonicotinoids disrupt memory, circadian behaviour and sleep. Sci Rep 2021; 11:2061. [PMID: 33479461 PMCID: PMC7820356 DOI: 10.1038/s41598-021-81548-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 12/28/2020] [Indexed: 02/06/2023] Open
Abstract
Globally, neonicotinoids are the most used insecticides, despite their well-documented sub-lethal effects on beneficial insects. Neonicotinoids are nicotinic acetylcholine receptor agonists. Memory, circadian rhythmicity and sleep are essential for efficient foraging and pollination and require nicotinic acetylcholine receptor signalling. The effect of field-relevant concentrations of the European Union-banned neonicotinoids: imidacloprid, clothianidin, thiamethoxam and thiacloprid were tested on Drosophila memory, circadian rhythms and sleep. Field-relevant concentrations of imidacloprid, clothianidin and thiamethoxam disrupted learning, behavioural rhythmicity and sleep whilst thiacloprid exposure only affected sleep. Exposure to imidacloprid and clothianidin prevented the day/night remodelling and accumulation of pigment dispersing factor (PDF) neuropeptide in the dorsal terminals of clock neurons. Knockdown of the neonicotinoid susceptible Dα1 and Dβ2 nicotinic acetylcholine receptor subunits in the mushroom bodies or clock neurons recapitulated the neonicotinoid like deficits in memory or sleep/circadian behaviour respectively. Disruption of learning, circadian rhythmicity and sleep are likely to have far-reaching detrimental effects on beneficial insects in the field.
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40
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Jepson JEC. Sleep: Astrocytes Take Their Toll on Tired Flies. Curr Biol 2021; 31:R27-R30. [PMID: 33434483 DOI: 10.1016/j.cub.2020.10.083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Calcium signalling in astrocytes modulates sleep, yet how astrocytes communicate with neural circuits that control sleep is unclear. A new study now uncovers a calcium-dependent relay between astrocytes and neurons that promotes sleep homeostasis in fruit flies.
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Affiliation(s)
- James E C Jepson
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.
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41
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Tasman K, Rands SA, Hodge JJ. The Neonicotinoid Insecticide Imidacloprid Disrupts Bumblebee Foraging Rhythms and Sleep. iScience 2020; 23:101827. [PMID: 33305183 PMCID: PMC7710657 DOI: 10.1016/j.isci.2020.101827] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 08/12/2020] [Accepted: 11/16/2020] [Indexed: 11/23/2022] Open
Abstract
Neonicotinoids have been implicated in the large declines observed in insects such as bumblebees, an important group of pollinators. Neonicotinoids are agonists of nicotinic acetylcholine receptors that are found throughout the insect central nervous system and are the main mediators of synaptic neurotransmission. These receptors are important for the function of the insect central clock and circadian rhythms. The clock allows pollinators to coincide their activity with the availability of floral resources and favorable flight temperatures, as well as impact learning, navigation, and communication. Here we show that exposure to the field-relevant concentration of 10 μg/L imidacloprid caused a reduction in bumblebee foraging activity, locomotion, and foraging rhythmicity. Foragers showed an increase in daytime sleep and an increase in the proportion of activity occurring at night. This could reduce foraging and pollination opportunities, reducing the ability of the colony to grow and reproduce, endangering bee populations and crop yields.
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Affiliation(s)
- Kiah Tasman
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK
| | - Sean A. Rands
- School of Biological Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol, BS8 1TQ, UK
| | - James J.L. Hodge
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK
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42
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High-Frequency Neuronal Bursting is Essential for Circadian and Sleep Behaviors in Drosophila. J Neurosci 2020; 41:689-710. [PMID: 33262246 DOI: 10.1523/jneurosci.2322-20.2020] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 11/04/2020] [Accepted: 11/09/2020] [Indexed: 02/08/2023] Open
Abstract
Circadian rhythms have been extensively studied in Drosophila; however, still little is known about how the electrical properties of clock neurons are specified. We have performed a behavioral genetic screen through the downregulation of candidate ion channels in the lateral ventral neurons (LNvs) and show that the hyperpolarization-activated cation current Ih is important for the behaviors that the LNvs influence: temporal organization of locomotor activity, analyzed in males, and sleep, analyzed in females. Using whole-cell patch clamp electrophysiology we demonstrate that small LNvs (sLNvs) are bursting neurons, and that Ih is necessary to achieve the high-frequency bursting firing pattern characteristic of both types of LNvs in females. Since firing in bursts has been associated to neuropeptide release, we hypothesized that Ih would be important for LNvs communication. Indeed, herein we demonstrate that Ih is fundamental for the recruitment of pigment dispersing factor (PDF) filled dense core vesicles (DCVs) to the terminals at the dorsal protocerebrum and for their timed release, and hence for the temporal coordination of circadian behaviors.SIGNIFICANCE STATEMENT Ion channels are transmembrane proteins with selective permeability to specific charged particles. The rich repertoire of parameters that may gate their opening state, such as voltage-sensitivity, modulation by second messengers and specific kinetics, make this protein family a determinant of neuronal identity. Ion channel structure is evolutionary conserved between vertebrates and invertebrates, making any discovery easily translatable. Through a screen to uncover ion channels with roles in circadian rhythms, we have identified the Ih channel as an important player in a subset of clock neurons of the fruit fly. We show that lateral ventral neurons (LNvs) need Ih to fire action potentials in a high-frequency bursting mode and that this is important for peptide transport and the control of behavior.
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43
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Blum ID, Keleş MF, Baz ES, Han E, Park K, Luu S, Issa H, Brown M, Ho MCW, Tabuchi M, Liu S, Wu MN. Astroglial Calcium Signaling Encodes Sleep Need in Drosophila. Curr Biol 2020; 31:150-162.e7. [PMID: 33186550 DOI: 10.1016/j.cub.2020.10.012] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 09/17/2020] [Accepted: 10/07/2020] [Indexed: 12/14/2022]
Abstract
Sleep is under homeostatic control, whereby increasing wakefulness generates sleep need and triggers sleep drive. However, the molecular and cellular pathways by which sleep need is encoded are poorly understood. In addition, the mechanisms underlying both how and when sleep need is transformed to sleep drive are unknown. Here, using ex vivo and in vivo imaging, we show in Drosophila that astroglial Ca2+ signaling increases with sleep need. We demonstrate that this signaling is dependent on a specific L-type Ca2+ channel and is necessary for homeostatic sleep rebound. Thermogenetically increasing Ca2+ in astrocytes induces persistent sleep behavior, and we exploit this phenotype to conduct a genetic screen for genes required for the homeostatic regulation of sleep. From this large-scale screen, we identify TyrRII, a monoaminergic receptor required in astrocytes for sleep homeostasis. TyrRII levels rise following sleep deprivation in a Ca2+-dependent manner, promoting further increases in astrocytic Ca2+ and resulting in a positive-feedback loop. Moreover, our findings suggest that astrocytes then transmit this sleep need to a sleep drive circuit by upregulating and releasing the interleukin-1 analog Spätzle, which then acts on Toll receptors on R5 neurons. These findings define astroglial Ca2+ signaling mechanisms encoding sleep need and reveal dynamic properties of the sleep homeostatic control system.
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Affiliation(s)
- Ian D Blum
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Mehmet F Keleş
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - El-Sayed Baz
- VIB Center for Brain and Disease Research and Department of Neurosciences, KU Leuven, Leuven 3000, Belgium
| | - Emily Han
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Kristen Park
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Skylar Luu
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Habon Issa
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Matt Brown
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Margaret C W Ho
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Masashi Tabuchi
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Sha Liu
- VIB Center for Brain and Disease Research and Department of Neurosciences, KU Leuven, Leuven 3000, Belgium.
| | - Mark N Wu
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA; Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21205, USA.
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44
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Dopamine Signaling in Wake-Promoting Clock Neurons Is Not Required for the Normal Regulation of Sleep in Drosophila. J Neurosci 2020; 40:9617-9633. [PMID: 33172977 DOI: 10.1523/jneurosci.1488-20.2020] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 10/15/2020] [Accepted: 10/21/2020] [Indexed: 11/21/2022] Open
Abstract
Dopamine is a wake-promoting neuromodulator in mammals and fruit flies. In Drosophila melanogaster, the network of clock neurons that drives sleep/activity cycles comprises both wake-promoting and sleep-promoting cell types. The large ventrolateral neurons (l-LNvs) and small ventrolateral neurons (s-LNvs) have been identified as wake-promoting neurons within the clock neuron network. The l-LNvs are innervated by dopaminergic neurons, and earlier work proposed that dopamine signaling raises cAMP levels in the l-LNvs and thus induces excitatory electrical activity (action potential firing), which results in wakefulness and inhibits sleep. Here, we test this hypothesis by combining cAMP imaging and patch-clamp recordings in isolated brains. We find that dopamine application indeed increases cAMP levels and depolarizes the l-LNvs, but, surprisingly, it does not result in increased firing rates. Downregulation of the excitatory D1-like dopamine receptor (Dop1R1) in the l-LNvs and s-LNvs, but not of Dop1R2, abolished the depolarization of l-LNvs in response to dopamine. This indicates that dopamine signals via Dop1R1 to the l-LNvs. Downregulation of Dop1R1 or Dop1R2 in the l-LNvs and s-LNvs does not affect sleep in males. Unexpectedly, we find a moderate decrease of daytime sleep with downregulation of Dop1R1 and of nighttime sleep with downregulation of Dop1R2. Since the l-LNvs do not use Dop1R2 receptors and the s-LNvs also respond to dopamine, we conclude that the s-LNvs are responsible for the observed decrease in nighttime sleep. In summary, dopamine signaling in the wake-promoting LNvs is not required for daytime arousal, but likely promotes nighttime sleep via the s-LNvs.SIGNIFICANCE STATEMENT In insect and mammalian brains, sleep-promoting networks are intimately linked to the circadian clock, and the mechanisms underlying sleep and circadian timekeeping are evolutionarily ancient and highly conserved. Here we show that dopamine, one important sleep modulator in flies and mammals, plays surprisingly complex roles in the regulation of sleep by clock-containing neurons. Dopamine inhibits neurons in a central brain sleep center to promote sleep and excites wake-promoting circadian clock neurons. It is therefore predicted to promote wakefulness through both of these networks. Nevertheless, our results reveal that dopamine acting on wake-promoting clock neurons promotes sleep, revealing a previously unappreciated complexity in the dopaminergic control of sleep.
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45
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Tackenberg MC, Giannoni-Guzmán MA, Sanchez-Perez E, Doll CA, Agosto-Rivera JL, Broadie K, Moore D, McMahon DG. Neonicotinoids disrupt circadian rhythms and sleep in honey bees. Sci Rep 2020; 10:17929. [PMID: 33087835 PMCID: PMC7578099 DOI: 10.1038/s41598-020-72041-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 07/02/2020] [Indexed: 12/14/2022] Open
Abstract
Honey bees are critical pollinators in ecosystems and agriculture, but their numbers have significantly declined. Declines in pollinator populations are thought to be due to multiple factors including habitat loss, climate change, increased vulnerability to disease and parasites, and pesticide use. Neonicotinoid pesticides are agonists of insect nicotinic cholinergic receptors, and sub-lethal exposures are linked to reduced honey bee hive survival. Honey bees are highly dependent on circadian clocks to regulate critical behaviors, such as foraging orientation and navigation, time-memory for food sources, sleep, and learning/memory processes. Because circadian clock neurons in insects receive light input through cholinergic signaling we tested for effects of neonicotinoids on honey bee circadian rhythms and sleep. Neonicotinoid ingestion by feeding over several days results in neonicotinoid accumulation in the bee brain, disrupts circadian rhythmicity in many individual bees, shifts the timing of behavioral circadian rhythms in bees that remain rhythmic, and impairs sleep. Neonicotinoids and light input act synergistically to disrupt bee circadian behavior, and neonicotinoids directly stimulate wake-promoting clock neurons in the fruit fly brain. Neonicotinoids disrupt honey bee circadian rhythms and sleep, likely by aberrant stimulation of clock neurons, to potentially impair honey bee navigation, time-memory, and social communication.
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Affiliation(s)
| | | | - Erik Sanchez-Perez
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
| | - Caleb A Doll
- Department of Pediatrics, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, 8004, USA
| | - José L Agosto-Rivera
- Department of Biology, University of Puerto Rico - Río Piedras, San Juan, PR, USA
| | - Kendal Broadie
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
| | - Darrell Moore
- Department of Biological Sciences, East Tennessee State University, Johnson City, TN, USA
| | - Douglas G McMahon
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA.
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA.
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46
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Mazzotta GM, Damulewicz M, Cusumano P. Better Sleep at Night: How Light Influences Sleep in Drosophila. Front Physiol 2020; 11:997. [PMID: 33013437 PMCID: PMC7498665 DOI: 10.3389/fphys.2020.00997] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 07/22/2020] [Indexed: 01/25/2023] Open
Abstract
Sleep-like states have been described in Drosophila and the mechanisms and factors that generate and define sleep-wake profiles in this model organism are being thoroughly investigated. Sleep is controlled by both circadian and homeostatic mechanisms, and environmental factors such as light, temperature, and social stimuli are fundamental in shaping and confining sleep episodes into the correct time of the day. Among environmental cues, light seems to have a prominent function in modulating the timing of sleep during the 24 h and, in this review, we will discuss the role of light inputs in modulating the distribution of the fly sleep-wake cycles. This phenomenon is of growing interest in the modern society, where artificial light exposure during the night is a common trait, opening the possibility to study Drosophila as a model organism for investigating shift-work disorders.
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Affiliation(s)
| | - Milena Damulewicz
- Department of Cell Biology and Imaging, Jagiellonian University, Kraków, Poland
| | - Paola Cusumano
- Department of Biology, University of Padova, Padua, Italy
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47
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Damulewicz M, Ispizua JI, Ceriani MF, Pyza EM. Communication Among Photoreceptors and the Central Clock Affects Sleep Profile. Front Physiol 2020; 11:993. [PMID: 32848895 PMCID: PMC7431659 DOI: 10.3389/fphys.2020.00993] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 07/22/2020] [Indexed: 12/17/2022] Open
Abstract
Light is one of the most important factors regulating rhythmical behavior of Drosophila melanogaster. It is received by different photoreceptors and entrains the circadian clock, which controls sleep. The retina is known to be essential for light perception, as it is composed of specialized light-sensitive cells which transmit signal to deeper parts of the brain. In this study we examined the role of specific photoreceptor types and peripheral oscillators located in these cells in the regulation of sleep pattern. We showed that sleep is controlled by the visual system in a very complex way. Photoreceptors expressing Rh1, Rh3 are involved in night-time sleep regulation, while cells expressing Rh5 and Rh6 affect sleep both during the day and night. Moreover, Hofbauer-Buchner (HB) eyelets which can directly contact with s-LN v s and l-LN v s play a wake-promoting function during the day. In addition, we showed that L2 interneurons, which receive signal from R1-6, form direct synaptic contacts with l-LN v s, which provides new light input to the clock network.
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Affiliation(s)
- Milena Damulewicz
- Department of Cell Biology and Imaging, Jagiellonian University, Kraków, Poland
| | - Juan I. Ispizua
- Laboratorio de Genética del Comportamiento, Fundación Instituto Leloir, IIBBA-CONICET, Buenos Aires, Argentina
| | - Maria F. Ceriani
- Laboratorio de Genética del Comportamiento, Fundación Instituto Leloir, IIBBA-CONICET, Buenos Aires, Argentina
| | - Elzbieta M. Pyza
- Department of Cell Biology and Imaging, Jagiellonian University, Kraków, Poland
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48
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Baik LS, Nave C, Au DD, Guda T, Chevez JA, Ray A, Holmes TC. Circadian Regulation of Light-Evoked Attraction and Avoidance Behaviors in Daytime- versus Nighttime-Biting Mosquitoes. Curr Biol 2020; 30:3252-3259.e3. [PMID: 32619483 DOI: 10.1016/j.cub.2020.06.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 04/24/2020] [Accepted: 06/02/2020] [Indexed: 11/16/2022]
Abstract
Mosquitoes pose widespread threats to humans and other animals as disease vectors [1]. Day- versus night-biting mosquitoes occupy distinct time-of-day niches [2, 3]. Here, we explore day- versus night-biting female and male mosquitoes' innate temporal attraction/avoidance behavioral responses to light and their regulation by circadian circuit and molecular mechanisms. Day-biting mosquitoes Aedes aegypti, particularly females, are attracted to light during the day regardless of spectra. In contrast, night-biting mosquitoes, Anopheles coluzzii, specifically avoid ultraviolet (UV) and blue light during the day. Behavioral attraction to/avoidance of light in both species change with time of day and show distinct sex and circadian neural circuit differences. Males of both diurnal and nocturnal mosquito species show reduced UV light avoidance in anticipation of evening onset relative to females. The circadian neural circuits of diurnal/day- and nocturnal/night-biting mosquitoes based on PERIOD (PER) and pigment-dispersing factor (PDF) expression show similar but distinct circuit organizations between species. The basis of diurnal versus nocturnal behaviors is driven by molecular clock timing, which cycles in anti-phase between day- versus night-biting mosquitoes. Observed differences at the neural circuit and protein levels provide insight into the fundamental basis underlying diurnality versus nocturnality. Molecular disruption of the circadian clock severely interferes with light-evoked attraction/avoidance behaviors in mosquitoes. In summary, attraction/avoidance behaviors show marked differences between day- versus night-biting mosquitoes, but both classes of mosquitoes are circadian and light regulated, which may be applied toward species-specific control of harmful mosquitoes.
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Affiliation(s)
- Lisa S Baik
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA 92697, USA
| | - Ceazar Nave
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA 92697, USA
| | - David D Au
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA 92697, USA
| | - Tom Guda
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Joshua A Chevez
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA 92697, USA
| | - Anandasankar Ray
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Todd C Holmes
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA 92697, USA.
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49
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Xu F, Kula-Eversole E, Iwanaszko M, Hutchison AL, Dinner A, Allada R. Circadian Clocks Function in Concert with Heat Shock Organizing Protein to Modulate Mutant Huntingtin Aggregation and Toxicity. Cell Rep 2020; 27:59-70.e4. [PMID: 30943415 PMCID: PMC7237104 DOI: 10.1016/j.celrep.2019.03.015] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 01/24/2019] [Accepted: 03/02/2019] [Indexed: 01/08/2023] Open
Abstract
Neurodegenerative diseases commonly involve the disruption of circadian rhythms. Studies indicate that mutant Huntingtin (mHtt), the cause of Huntington’s disease (HD), disrupts circadian rhythms often before motor symptoms are evident. Yet little is known about the molecular mechanisms by which mHtt impairs circadian rhythmicity and whether circadian clocks can modulate HD pathogenesis. To address this question, we used a Drosophila HD model. We found that both environmental and genetic perturbations of the circadian clock alter mHtt-mediated neurodegeneration. To identify potential genetic pathways that mediate these effects, we applied a behavioral platform to screen for clock-regulated HD suppressors, identifying a role for Heat Shock Protein 70/90 Organizing Protein (Hop). Hop knockdown paradoxically reduces mHtt aggregation and toxicity. These studies demonstrate a role for the circadian clock in a neurodegenerative disease model and reveal a clock-regulated molecular and cellular pathway that links clock function to neurodegenerative disease. Disruption of circadian rhythms is frequently observed across a range of neurodegenerative diseases. Here, Xu et al. demonstrate that perturbation of circadian clocks alters the toxicity of the mutant Huntingtin protein, the cause of Huntington’s disease (HD). Moreover, they reveal a key mechanistic link between the clock and HD.
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Affiliation(s)
- Fangke Xu
- Department of Neurobiology, Northwestern University, Evanston, IL, USA
| | | | - Marta Iwanaszko
- Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Alan L Hutchison
- Medical Scientist Training Program, University of Chicago, Chicago, IL, USA
| | - Aaron Dinner
- James Franck Institute, University of Chicago, Chicago, IL, USA
| | - Ravi Allada
- Department of Neurobiology, Northwestern University, Evanston, IL, USA.
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50
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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: 3.2] [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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