101
|
Abstract
Sleep is essential for proper brain function in mammals and insects. During sleep, animals are disconnected from the external world; they show high arousal thresholds and changed brain activity. Sleep deprivation results in a sleep rebound. Research using the fruit fly, Drosophila melanogaster, has helped us understand the genetic and neuronal control of sleep. Genes involved in sleep control code for ion channels, factors influencing neurotransmission and neuromodulation, and proteins involved in the circadian clock. The neurotransmitters/neuromodulators involved in sleep control are GABA, dopamine, acetylcholine, serotonin, and several neuropeptides. Sleep is controlled by the interplay between sleep homeostasis and the circadian clock. Putative sleep-wake centers are located in higher-order brain centers that are indirectly connected to the circadian clock network. The primary function of sleep appears to be the downscaling of synapses that have been built up during wakefulness. Thus, brain homeostasis is maintained and learning and memory are assured.
Collapse
Affiliation(s)
- Charlotte Helfrich-Förster
- Neurobiology and Genetics, Theodor-Boveri-Institute, Biocenter, University of Würzburg, 97074 Würzburg, Germany;
| |
Collapse
|
102
|
Donlea JM, Pimentel D, Talbot CB, Kempf A, Omoto JJ, Hartenstein V, Miesenböck G. Recurrent Circuitry for Balancing Sleep Need and Sleep. Neuron 2018; 97:378-389.e4. [PMID: 29307711 PMCID: PMC5779612 DOI: 10.1016/j.neuron.2017.12.016] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 10/13/2017] [Accepted: 12/07/2017] [Indexed: 10/26/2022]
Abstract
Sleep-promoting neurons in the dorsal fan-shaped body (dFB) of Drosophila are integral to sleep homeostasis, but how these cells impose sleep on the organism is unknown. We report that dFB neurons communicate via inhibitory transmitters, including allatostatin-A (AstA), with interneurons connecting the superior arch with the ellipsoid body of the central complex. These "helicon cells" express the galanin receptor homolog AstA-R1, respond to visual input, gate locomotion, and are inhibited by AstA, suggesting that dFB neurons promote rest by suppressing visually guided movement. Sleep changes caused by enhanced or diminished allatostatinergic transmission from dFB neurons and by inhibition or optogenetic stimulation of helicon cells support this notion. Helicon cells provide excitation to R2 neurons of the ellipsoid body, whose activity-dependent plasticity signals rising sleep pressure to the dFB. By virtue of this autoregulatory loop, dFB-mediated inhibition interrupts processes that incur a sleep debt, allowing restorative sleep to rebalance the books. VIDEO ABSTRACT.
Collapse
Affiliation(s)
- Jeffrey M Donlea
- Centre for Neural Circuits and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK; Department of Neurobiology, David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, CA 90095-1763, USA.
| | - Diogo Pimentel
- Centre for Neural Circuits and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - Clifford B Talbot
- Centre for Neural Circuits and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - Anissa Kempf
- Centre for Neural Circuits and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - Jaison J Omoto
- Department of Neurobiology, David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, CA 90095-1763, USA; Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA 90095-1606, USA
| | - Volker Hartenstein
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA 90095-1606, USA
| | - Gero Miesenböck
- Centre for Neural Circuits and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK.
| |
Collapse
|
103
|
Abstract
Despite decades of intense study, the functions of sleep are still shrouded in mystery. The difficulty in understanding these functions can be at least partly attributed to the varied manifestations of sleep in different animals. Daily sleep duration can range from 4-20 hrs among mammals, and sleep can manifest throughout the brain, or it can alternate over time between cerebral hemispheres, depending on the species. Ecological factors are likely to have shaped these and other sleep behaviors during evolution by altering the properties of conserved arousal circuits in the brain. Nonetheless, core functions of sleep are likely to have arisen early and to have persisted to the present day in diverse organisms. This review will discuss the evolutionary forces that may be responsible for phylogenetic differences in sleep and the potential core functions that sleep fulfills.
Collapse
Affiliation(s)
- William J Joiner
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093-0636, USA; Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, CA 92093-0636, USA; Neurosciences Graduate Program, University of California San Diego, La Jolla, CA 92093-0636, USA; Center for Circadian Biology, University of California San Diego, La Jolla, CA 92093-0636, USA.
| |
Collapse
|
104
|
Ichinose T, Tanimoto H, Yamagata N. Behavioral Modulation by Spontaneous Activity of Dopamine Neurons. Front Syst Neurosci 2017; 11:88. [PMID: 29321731 PMCID: PMC5732226 DOI: 10.3389/fnsys.2017.00088] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 11/14/2017] [Indexed: 01/11/2023] Open
Abstract
Dopamine modulates a variety of animal behaviors that range from sleep and learning to courtship and aggression. Besides its well-known phasic firing to natural reward, a substantial number of dopamine neurons (DANs) are known to exhibit ongoing intrinsic activity in the absence of an external stimulus. While accumulating evidence points at functional implications for these intrinsic "spontaneous activities" of DANs in cognitive processes, a causal link to behavior and its underlying mechanisms has yet to be elucidated. Recent physiological studies in the model organism Drosophila melanogaster have uncovered that DANs in the fly brain are also spontaneously active, and that this activity reflects the behavioral/internal states of the animal. Strikingly, genetic manipulation of basal DAN activity resulted in behavioral alterations in the fly, providing critical evidence that links spontaneous DAN activity to behavioral states. Furthermore, circuit-level analyses have started to reveal cellular and molecular mechanisms that mediate or regulate spontaneous DAN activity. Through reviewing recent findings in different animals with the major focus on flies, we will discuss potential roles of this physiological phenomenon in directing animal behaviors.
Collapse
Affiliation(s)
- Toshiharu Ichinose
- Graduate School of Life Sciences, Tohoku University, Sendai, Japan.,Department of Neuroscience of Disease, Center for Transdisciplinary Research, Niigata University, Niigata, Japan
| | - Hiromu Tanimoto
- Graduate School of Life Sciences, Tohoku University, Sendai, Japan
| | | |
Collapse
|
105
|
Donlea JM. Neuronal and molecular mechanisms of sleep homeostasis. CURRENT OPINION IN INSECT SCIENCE 2017; 24:51-57. [PMID: 29208223 DOI: 10.1016/j.cois.2017.09.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 09/13/2017] [Accepted: 09/13/2017] [Indexed: 06/07/2023]
Abstract
Sleep is necessary for survival, and prolonged waking causes a homeostatic increase in the need for recovery sleep. Homeostasis is a core component of sleep regulation and has been tightly conserved across evolution from invertebrates to man. Homeostatic sleep regulation was first identified among insects in cockroaches several decades ago, but the characterization of sleep rebound in Drosophila melanogaster opened the use of insect model species to understand homeostatic functions and regulation of sleep. This review describes circuits in two neuropil structures, the central complex and mushroom bodies, that influence sleep homeostasis and neuromodulatory systems that influence the accrual of homeostatic sleep need.
Collapse
Affiliation(s)
- Jeffrey M Donlea
- Department of Neurobiology, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA 90095-1763, USA.
| |
Collapse
|
106
|
Rosbash M. A 50-Year Personal Journey: Location, Gene Expression, and Circadian Rhythms. Cold Spring Harb Perspect Biol 2017; 9:cshperspect.a032516. [PMID: 28600396 DOI: 10.1101/cshperspect.a032516] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
I worked almost exclusively on nucleic acids and gene expression from the age of 19 as an undergraduate until the age of 38 as an associate professor. Mentors featured prominently in my choice of paths. My friendship with influential Brandeis colleagues then persuaded me that genetics was an important tool for studying gene expression, and I switched my experimental organism to yeast for this reason. Several years later, friendship also played a prominent role in my beginning work on circadian rhythms. As luck would have it, gene expression as well as genetics turned out to be important for circadian timekeeping. As a consequence, background and training put my laboratory in an excellent position to contribute to this aspect of the circadian problem. The moral of the story is, as in real estate, "location, location, location."
Collapse
Affiliation(s)
- Michael Rosbash
- Howard Hughes Medical Institute, National Center for Behavioral Genomics and Department of Biology, Brandeis University, Waltham, Massachusetts 02454
| |
Collapse
|
107
|
Oscillatory brain activity in spontaneous and induced sleep stages in flies. Nat Commun 2017; 8:1815. [PMID: 29180766 PMCID: PMC5704022 DOI: 10.1038/s41467-017-02024-y] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 11/01/2017] [Indexed: 12/03/2022] Open
Abstract
Sleep is a dynamic process comprising multiple stages, each associated with distinct electrophysiological properties and potentially serving different functions. While these phenomena are well described in vertebrates, it is unclear if invertebrates have distinct sleep stages. We perform local field potential (LFP) recordings on flies spontaneously sleeping, and compare their brain activity to flies induced to sleep using either genetic activation of sleep-promoting circuitry or the GABAA agonist Gaboxadol. We find a transitional sleep stage associated with a 7–10 Hz oscillation in the central brain during spontaneous sleep. Oscillatory activity is also evident when we acutely activate sleep-promoting neurons in the dorsal fan-shaped body (dFB) of Drosophila. In contrast, sleep following Gaboxadol exposure is characterized by low-amplitude LFPs, during which dFB-induced effects are suppressed. Sleep in flies thus appears to involve at least two distinct stages: increased oscillatory activity, particularly during sleep induction, followed by desynchronized or decreased brain activity. Sleep in mammals comprises physiologically and functionally distinct stages. Here, the authors report a transitional sleep stage in Drosophila associated with 7–10 Hz oscillatory activity that can be obtained through activation of the sleep-promoting neurons of the dorsal fan-shaped body.
Collapse
|
108
|
Stahl BA, Slocumb ME, Chaitin H, DiAngelo JR, Keene AC. Sleep-Dependent Modulation of Metabolic Rate in Drosophila. Sleep 2017; 40:3852476. [PMID: 28541527 DOI: 10.1093/sleep/zsx084] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 05/24/2017] [Indexed: 12/17/2022] Open
Abstract
Study Objectives Dysregulation of sleep is associated with metabolic diseases, and metabolic rate (MR) is acutely regulated by sleep-wake behavior. In humans and rodent models, sleep loss is associated with obesity, reduced metabolic rate, and negative energy balance, yet little is known about the neural mechanisms governing interactions between sleep and metabolism. Methods We have developed a system to simultaneously measure sleep and MR in individual Drosophila, allowing for interrogation of neural systems governing interactions between sleep and metabolic rate. Results Like mammals, MR in flies is reduced during sleep and increased during sleep deprivation suggesting sleep-dependent regulation of MR is conserved across phyla. The reduction of MR during sleep is not simply a consequence of inactivity because MR is reduced ~30 minutes following the onset of sleep, raising the possibility that CO2 production provides a metric to distinguish different sleep states in the fruit fly. To examine the relationship between sleep and metabolism, we determined basal and sleep-dependent changes in MR is reduced in starved flies, suggesting that starvation inhibits normal sleep-associated effects on metabolic rate. Further, translin mutant flies that fail to suppress sleep during starvation demonstrate a lower basal metabolic rate, but this rate was further reduced in response to starvation, revealing that regulation of starvation-induced changes in MR and sleep duration are genetically distinct. Conclusions Therefore, this system provides the unique ability to simultaneously measure sleep and oxidative metabolism, providing novel insight into the physiological changes associated with sleep and wakefulness in the fruit fly.
Collapse
Affiliation(s)
- Bethany A Stahl
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL
| | - Melissa E Slocumb
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL.,Integrative Biology Graduate Program, Jupiter, FL
| | - Hersh Chaitin
- Department of Ocean and Mechanical Engineering, Florida Atlantic University, Boca Raton, FL
| | | | - Alex C Keene
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL
| |
Collapse
|
109
|
Seugnet L, Dissel S, Thimgan M, Cao L, Shaw PJ. Identification of Genes that Maintain Behavioral and Structural Plasticity during Sleep Loss. Front Neural Circuits 2017; 11:79. [PMID: 29109678 PMCID: PMC5660066 DOI: 10.3389/fncir.2017.00079] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 10/05/2017] [Indexed: 11/23/2022] Open
Abstract
Although patients with primary insomnia experience sleep disruption, they are able to maintain normal performance on a variety of cognitive tasks. This observation suggests that insomnia may be a condition where predisposing factors simultaneously increase the risk for insomnia and also mitigate against the deleterious consequences of waking. To gain insight into processes that might regulate sleep and buffer neuronal circuits during sleep loss, we manipulated three genes, fat facet (faf), highwire (hiw) and the GABA receptor Resistance to dieldrin (Rdl), that were differentially modulated in a Drosophila model of insomnia. Our results indicate that increasing faf and decreasing hiw or Rdl within wake-promoting large ventral lateral clock neurons (lLNvs) induces sleep loss. As expected, sleep loss induced by decreasing hiw in the lLNvs results in deficits in short-term memory and increases of synaptic growth. However, sleep loss induced by knocking down Rdl in the lLNvs protects flies from sleep-loss induced deficits in short-term memory and increases in synaptic markers. Surprisingly, decreasing hiw and Rdl within the Mushroom Bodies (MBs) protects against the negative effects of sleep deprivation (SD) as indicated by the absence of a subsequent homeostatic response, or deficits in short-term memory. Together these results indicate that specific genes are able to disrupt sleep and protect against the negative consequences of waking in a circuit dependent manner.
Collapse
Affiliation(s)
- Laurent Seugnet
- Centre de Recherche en Neurosciences de Lyon, U1028/UMR 5292, Team WAKING, Université Claude Bernard Lyon 1, INSERM U1028, CNRS UMR 5292, Lyon, France
| | - Stephane Dissel
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
| | - Matthew Thimgan
- Department of Biological Sciences, Missouri University of Science and Technology, Rolla, MO, United States
| | - Lijuan Cao
- 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
| |
Collapse
|
110
|
Qian Y, Cao Y, Deng B, Yang G, Li J, Xu R, Zhang D, Huang J, Rao Y. Sleep homeostasis regulated by 5HT2b receptor in a small subset of neurons in the dorsal fan-shaped body of drosophila. eLife 2017; 6:26519. [PMID: 28984573 PMCID: PMC5648528 DOI: 10.7554/elife.26519] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 10/05/2017] [Indexed: 12/14/2022] Open
Abstract
Our understanding of the molecular mechanisms underlying sleep homeostasis is limited. We have taken a systematic approach to study neural signaling by the transmitter 5-hydroxytryptamine (5-HT) in drosophila. We have generated knockout and knockin lines for Trh, the 5-HT synthesizing enzyme and all five 5-HT receptors, making it possible for us to determine their expression patterns and to investigate their functional roles. Loss of the Trh, 5HT1a or 5HT2b gene decreased sleep time whereas loss of the Trh or 5HT2b gene diminished sleep rebound after sleep deprivation. 5HT2b expression in a small subset of, probably a single pair of, neurons in the dorsal fan-shaped body (dFB) is functionally essential: elimination of the 5HT2b gene from these neurons led to loss of sleep homeostasis. Genetic ablation of 5HT2b neurons in the dFB decreased sleep and impaired sleep homeostasis. Our results have shown that serotonergic signaling in specific neurons is required for the regulation of sleep homeostasis.
Collapse
Affiliation(s)
- Yongjun Qian
- Peking-Tsinghua Center for Life Sciences, State Key Laboratory of Biomembrane and Membrane Biology, PKU-IDG/McGovern Institute For Brain Research, Beijing Advanced Innovation Center for Genomics, School of Life Sciences, Peking University, Beijing, China.,National Institute of Biological Sciences, Beijing, China
| | - Yue Cao
- Peking-Tsinghua Center for Life Sciences, State Key Laboratory of Biomembrane and Membrane Biology, PKU-IDG/McGovern Institute For Brain Research, Beijing Advanced Innovation Center for Genomics, School of Life Sciences, Peking University, Beijing, China
| | - Bowen Deng
- Peking-Tsinghua Center for Life Sciences, State Key Laboratory of Biomembrane and Membrane Biology, PKU-IDG/McGovern Institute For Brain Research, Beijing Advanced Innovation Center for Genomics, School of Life Sciences, Peking University, Beijing, China.,National Institute of Biological Sciences, Beijing, China
| | - Guang Yang
- Peking-Tsinghua Center for Life Sciences, State Key Laboratory of Biomembrane and Membrane Biology, PKU-IDG/McGovern Institute For Brain Research, Beijing Advanced Innovation Center for Genomics, School of Life Sciences, Peking University, Beijing, China
| | - Jiayun Li
- Peking-Tsinghua Center for Life Sciences, State Key Laboratory of Biomembrane and Membrane Biology, PKU-IDG/McGovern Institute For Brain Research, Beijing Advanced Innovation Center for Genomics, School of Life Sciences, Peking University, Beijing, China
| | - Rui Xu
- School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Dandan Zhang
- School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Juan Huang
- School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Yi Rao
- Peking-Tsinghua Center for Life Sciences, State Key Laboratory of Biomembrane and Membrane Biology, PKU-IDG/McGovern Institute For Brain Research, Beijing Advanced Innovation Center for Genomics, School of Life Sciences, Peking University, Beijing, China.,National Institute of Biological Sciences, Beijing, China
| |
Collapse
|
111
|
Rogdi Defines GABAergic Control of a Wake-promoting Dopaminergic Pathway to Sustain Sleep in Drosophila. Sci Rep 2017; 7:11368. [PMID: 28900300 PMCID: PMC5595912 DOI: 10.1038/s41598-017-11941-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 09/01/2017] [Indexed: 12/12/2022] Open
Abstract
Kohlschutter-Tönz syndrome (KTS) is a rare genetic disorder with neurological dysfunctions including seizure and intellectual impairment. Mutations at the Rogdi locus have been linked to development of KTS, yet the underlying mechanisms remain elusive. Here we demonstrate that a Drosophila homolog of Rogdi acts as a novel sleep-promoting factor by supporting a specific subset of gamma-aminobutyric acid (GABA) transmission. Rogdi mutant flies displayed insomnia-like behaviors accompanied by sleep fragmentation and delay in sleep initiation. The sleep suppression phenotypes were rescued by sustaining GABAergic transmission primarily via metabotropic GABA receptors or by blocking wake-promoting dopaminergic pathways. Transgenic rescue further mapped GABAergic neurons as a cell-autonomous locus important for Rogdi-dependent sleep, implying metabotropic GABA transmission upstream of the dopaminergic inhibition of sleep. Consistently, an agonist specific to metabotropic but not ionotropic GABA receptors titrated the wake-promoting effects of dopaminergic neuron excitation. Taken together, these data provide the first genetic evidence that implicates Rogdi in sleep regulation via GABAergic control of dopaminergic signaling. Given the strong relevance of GABA to epilepsy, we propose that similar mechanisms might underlie the neural pathogenesis of Rogdi-associated KTS.
Collapse
|
112
|
Dove AE, Cook BL, Irgebay Z, Vecsey CG. Mechanisms of sleep plasticity due to sexual experience in Drosophila melanogaster. Physiol Behav 2017; 180:146-158. [PMID: 28851647 DOI: 10.1016/j.physbeh.2017.08.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 08/23/2017] [Accepted: 08/25/2017] [Indexed: 10/19/2022]
Abstract
Sleep can be altered by an organism's previous experience. For instance, female Drosophila melanogaster experience a post-mating reduction in daytime sleep that is purportedly mediated by sex peptide (SP), one of many seminal fluid proteins (SFPs) transferred from male to female during mating. In the present study, we first characterized this mating effect on sleep more fully, as it had previously only been tested in young flies under 12h light/12h dark conditions. We found that mating reduced sleep equivalently in 3-day-old or 14-day-old females, and could even occur in females who had been mated previously, suggesting that there is not a developmental critical period for the suppression of sleep by mating. In conditions of constant darkness, circadian rhythms were not affected by prior mating. In either constant darkness or constant light, the sleep reduction due to mating was no longer confined to the subjective day but could be observed throughout the 24-hour period. This suggests that the endogenous clock may dictate the timing of when the mating effect on sleep is expressed. We recently reported that genetic elimination of SP only partially blocked the post-mating female siesta sleep reduction, suggesting that the effect was unlikely to be governed solely by SP. We found here that the daytime sleep reduction was also reduced but not eliminated in females mated to mutant males lacking the vast majority of SFPs. This suggested that SFPs other than SP play a minimal role in the mating effect on sleep, and that additional non-SFP signals from the male might be involved. Males lacking sperm were able to induce a normal initial mating effect on female sleep, although the effect declined more rapidly in these females. This result indicated that neither the presence of sperm within the female reproductive tract nor female impregnation are required for the initial mating effect on sleep to occur, although sperm may serve to prolong the effect. Finally, we tested for contributions from other aspects of the mating experience. NorpA and eya2 mutants with disrupted vision showed normal mating effects on sleep. By separating males from females with a mesh, we found that visual and olfactory stimuli from male exposure, in the absence of physical contact, could not replicate the mating effect. Further, in ken/barbie male flies lacking external genitalia, courtship and physical contact without ejaculation were also unable to replicate the mating effect. These findings confirmed that the influence of mating on sleep does in fact require male/female contact including copulation, but may not be mediated exclusively by SP transfer.
Collapse
Affiliation(s)
- Abigail E Dove
- Biology Department, Swarthmore College, 500 College Avenue, Swarthmore, PA 19081, United States
| | - Brianne L Cook
- Neuroscience Program, Skidmore College, 815 N. Broadway, Saratoga Springs, NY 12866, United States
| | - Zhazira Irgebay
- Biology Department, Swarthmore College, 500 College Avenue, Swarthmore, PA 19081, United States
| | - Christopher G Vecsey
- Biology Department, Swarthmore College, 500 College Avenue, Swarthmore, PA 19081, United States; Neuroscience Program, Skidmore College, 815 N. Broadway, Saratoga Springs, NY 12866, United States.
| |
Collapse
|
113
|
Allada R, Cirelli C, Sehgal A. Molecular Mechanisms of Sleep Homeostasis in Flies and Mammals. Cold Spring Harb Perspect Biol 2017; 9:a027730. [PMID: 28432135 PMCID: PMC5538413 DOI: 10.1101/cshperspect.a027730] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Sleep is homeostatically regulated with sleep pressure accumulating with the increasing duration of prior wakefulness. Yet, a clear understanding of the molecular components of the homeostat, as well as the molecular and cellular processes they sense and control to regulate sleep intensity and duration, remain a mystery. Here, we will discuss the cellular and molecular basis of sleep homeostasis, first focusing on the best homeostatic sleep marker in vertebrates, slow wave activity; second, moving to the molecular genetic analysis of sleep homeostasis in the fruit fly Drosophila; and, finally, discussing more systemic aspects of sleep homeostasis.
Collapse
Affiliation(s)
- Ravi Allada
- Department of Neurobiology, Northwestern University, Evanston, Ilinois 60208
| | - Chiara Cirelli
- Department of Psychiatry, University of Wisconsin-Madison, Madison, Wisconsin 53719
| | - Amita Sehgal
- Department of Neuroscience, Perelman School of Medicine at University of Pennsylvania, Philadelphia, Pennsylvania 19104-6058
| |
Collapse
|
114
|
Abstract
How the brain effectively switches between and maintains global states, such as sleep and wakefulness, is not yet understood. We used brainwide functional imaging at single-cell resolution to show that during the developmental stage of lethargus, the Caenorhabditis elegans brain is predisposed to global quiescence, characterized by systemic down-regulation of neuronal activity. Only a few specific neurons are exempt from this effect. In the absence of external arousing cues, this quiescent brain state arises by the convergence of neuronal activities toward a fixed-point attractor embedded in an otherwise dynamic neural state space. We observed efficient spontaneous and sensory-evoked exits from quiescence. Our data support the hypothesis that during global states such as sleep, neuronal networks are drawn to a baseline mode and can be effectively reactivated by signaling from arousing circuits.
Collapse
Affiliation(s)
- Annika L A Nichols
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria
| | - Tomáš Eichler
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria
| | - Richard Latham
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria
| | - Manuel Zimmer
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria.
| |
Collapse
|
115
|
Chung BY, Ro J, Hutter SA, Miller KM, Guduguntla LS, Kondo S, Pletcher SD. Drosophila Neuropeptide F Signaling Independently Regulates Feeding and Sleep-Wake Behavior. Cell Rep 2017; 19:2441-2450. [PMID: 28636933 PMCID: PMC5536846 DOI: 10.1016/j.celrep.2017.05.085] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 04/07/2017] [Accepted: 05/23/2017] [Indexed: 12/27/2022] Open
Abstract
Proper regulation of sleep-wake behavior and feeding is essential for organismal health and survival. While previous studies have isolated discrete neural loci and substrates important for either sleep or feeding, how the brain is organized to coordinate both processes with respect to one another remains poorly understood. Here, we provide evidence that the Drosophila Neuropeptide F (NPF) network forms a critical component of both adult sleep and feeding regulation. Activation of NPF signaling in the brain promotes wakefulness and adult feeding, likely through its cognate receptor NPFR. Flies carrying a loss-of-function NPF allele do not suppress sleep following prolonged starvation conditions, suggesting that NPF acts as a hunger signal to keep the animal awake. NPF-expressing cells, specifically those expressing the circadian photoreceptor cryptochrome, are largely responsible for changes to sleep behavior caused by NPF neuron activation, but not feeding, demonstrating that different NPF neurons separately drive wakefulness and hunger.
Collapse
Affiliation(s)
- Brian Y Chung
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jennifer Ro
- Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Sabine A Hutter
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Kylie M Miller
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Lakshmi S Guduguntla
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Shu Kondo
- Genetic Strains Research Center, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
| | - Scott D Pletcher
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA; Institute of Gerontology, University of Michigan, Ann Arbor, MI 48109, USA.
| |
Collapse
|
116
|
Abstract
Sleep homeostasis is a fundamental property of vigilance state regulation that is highly conserved across species. Neuronal systems and circuits that underlie sleep homeostasis are not well understood. In Drosophila, a neuronal circuit involving neurons in the ellipsoid body and in the dorsal Fan-shaped body is a candidate for both tracing sleep need during waking and translating it to increased sleep drive and expression. Sleep homeostasis in rats and mice involves multiple neuromodulators acting on multiple wake- and sleep-promoting neuronal systems. A functional central homeostat emerges from A1 receptor mediated actions of adenosine on wake-promoting neurons in the basal forebrain and hypothalamus, and A2A adenosine receptor-mediated actions on sleep-promoting neurons in the preoptic hypothalamus and nucleus accumbens.
Collapse
|
117
|
Sleep loss and structural plasticity. Curr Opin Neurobiol 2017; 44:1-7. [DOI: 10.1016/j.conb.2016.12.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 12/21/2016] [Indexed: 12/14/2022]
|
118
|
Artiushin G, Sehgal A. The Drosophila circuitry of sleep-wake regulation. Curr Opin Neurobiol 2017; 44:243-250. [PMID: 28366532 PMCID: PMC10826075 DOI: 10.1016/j.conb.2017.03.004] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2017] [Revised: 03/03/2017] [Accepted: 03/10/2017] [Indexed: 12/20/2022]
Abstract
Sleep is a deeply conserved, yet fundamentally mysterious behavioral state. Knowledge of the circuitry of sleep-wake regulation is an essential step in understanding the physiology of the sleeping brain. Recent efforts in Drosophila have revealed new populations which impact sleep, as well as provided unprecedented mechanistic and electrophysiological detail of established sleep-regulating neurons. Multiple, distributed centers of sleep-wake circuitry exist in the fly, including the mushroom bodies, central complex and the circadian clock cells. Intriguingly, certain populations have been implicated in specific roles in homeostatic rebound sleep, occurring after sleep loss. In short, our knowledge of fly sleep circuitry advances towards a greater view of brain-wide connectivity and integration of the signals and correlates of the state of sleep.
Collapse
Affiliation(s)
- Gregory Artiushin
- Howard Hughes Medical Institute, Chronobiology Program, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Amita Sehgal
- Howard Hughes Medical Institute, Chronobiology Program, University of Pennsylvania, Philadelphia, PA 19104, USA.
| |
Collapse
|
119
|
Circadian Rhythms and Sleep in Drosophila melanogaster. Genetics 2017; 205:1373-1397. [PMID: 28360128 DOI: 10.1534/genetics.115.185157] [Citation(s) in RCA: 226] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 11/17/2016] [Indexed: 02/07/2023] Open
Abstract
The advantages of the model organism Drosophila melanogaster, including low genetic redundancy, functional simplicity, and the ability to conduct large-scale genetic screens, have been essential for understanding the molecular nature of circadian (∼24 hr) rhythms, and continue to be valuable in discovering novel regulators of circadian rhythms and sleep. In this review, we discuss the current understanding of these interrelated biological processes in Drosophila and the wider implications of this research. Clock genes period and timeless were first discovered in large-scale Drosophila genetic screens developed in the 1970s. Feedback of period and timeless on their own transcription forms the core of the molecular clock, and accurately timed expression, localization, post-transcriptional modification, and function of these genes is thought to be critical for maintaining the circadian cycle. Regulators, including several phosphatases and kinases, act on different steps of this feedback loop to ensure strong and accurately timed rhythms. Approximately 150 neurons in the fly brain that contain the core components of the molecular clock act together to translate this intracellular cycling into rhythmic behavior. We discuss how different groups of clock neurons serve different functions in allowing clocks to entrain to environmental cues, driving behavioral outputs at different times of day, and allowing flexible behavioral responses in different environmental conditions. The neuropeptide PDF provides an important signal thought to synchronize clock neurons, although the details of how PDF accomplishes this function are still being explored. Secreted signals from clock neurons also influence rhythms in other tissues. SLEEP is, in part, regulated by the circadian clock, which ensures appropriate timing of sleep, but the amount and quality of sleep are also determined by other mechanisms that ensure a homeostatic balance between sleep and wake. Flies have been useful for identifying a large set of genes, molecules, and neuroanatomic loci important for regulating sleep amount. Conserved aspects of sleep regulation in flies and mammals include wake-promoting roles for catecholamine neurotransmitters and involvement of hypothalamus-like regions, although other neuroanatomic regions implicated in sleep in flies have less clear parallels. Sleep is also subject to regulation by factors such as food availability, stress, and social environment. We are beginning to understand how the identified molecules and neurons interact with each other, and with the environment, to regulate sleep. Drosophila researchers can also take advantage of increasing mechanistic understanding of other behaviors, such as learning and memory, courtship, and aggression, to understand how sleep loss impacts these behaviors. Flies thus remain a valuable tool for both discovery of novel molecules and deep mechanistic understanding of sleep and circadian rhythms.
Collapse
|
120
|
Machado DR, Afonso DJ, Kenny AR, Öztu Rk-Çolak A, Moscato EH, Mainwaring B, Kayser M, Koh K. Identification of octopaminergic neurons that modulate sleep suppression by male sex drive. eLife 2017; 6. [PMID: 28510528 PMCID: PMC5433852 DOI: 10.7554/elife.23130] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 04/25/2017] [Indexed: 12/20/2022] Open
Abstract
Molecular and circuit mechanisms for balancing competing drives are not well understood. While circadian and homeostatic mechanisms generally ensure sufficient sleep at night, other pressing needs can overcome sleep drive. Here, we demonstrate that the balance between sleep and sex drives determines whether male flies sleep or court, and identify a subset of octopaminergic neurons (MS1) that regulate sleep specifically in males. When MS1 neurons are activated, isolated males sleep less, and when MS1 neurons are silenced, the normal male sleep suppression in female presence is attenuated and mating behavior is impaired. MS1 neurons do not express the sexually dimorphic FRUITLESS (FRU) transcription factor, but form male-specific contacts with FRU-expressing neurons; calcium imaging experiments reveal bidirectional functional connectivity between MS1 and FRU neurons. We propose octopaminergic MS1 neurons interact with the FRU network to mediate sleep suppression by male sex drive.
Collapse
Affiliation(s)
- Daniel R Machado
- Department of Neuroscience, the Farber Institute for Neurosciences, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, United States.,Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal
| | - Dinis Js Afonso
- Department of Neuroscience, the Farber Institute for Neurosciences, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, United States.,Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal
| | - Alexandra R Kenny
- Department of Neuroscience, the Farber Institute for Neurosciences, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, United States
| | - Arzu Öztu Rk-Çolak
- Department of Neuroscience, the Farber Institute for Neurosciences, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, United States
| | - Emilia H Moscato
- Departments of Psychiatry and Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, United States
| | - Benjamin Mainwaring
- Departments of Psychiatry and Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, United States
| | - Matthew Kayser
- Departments of Psychiatry and Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, United States
| | - Kyunghee Koh
- Department of Neuroscience, the Farber Institute for Neurosciences, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, United States
| |
Collapse
|
121
|
Eban-Rothschild A, Giardino WJ, de Lecea L. To sleep or not to sleep: neuronal and ecological insights. Curr Opin Neurobiol 2017; 44:132-138. [PMID: 28500869 DOI: 10.1016/j.conb.2017.04.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 04/07/2017] [Accepted: 04/20/2017] [Indexed: 12/13/2022]
Abstract
Daily, animals need to decide when to stop engaging in cognitive processes and behavioral responses to the environment, and go to sleep. The main processes regulating the daily organization of sleep and wakefulness are circadian rhythms and homeostatic sleep pressure. In addition, motivational processes such as food seeking and predator evasion can modulate sleep/wake behaviors. Here, we discuss the principal processes regulating the propensity to stay awake or go to sleep-focusing on neuronal and behavioral aspects. We first introduce the neuronal populations involved in sleep/wake regulation. Next, we describe the circadian and homeostatic drives for sleep. Then, we highlight studies demonstrating various effects of motivational processes on sleep/wake behaviors, and discuss possible neuronal mechanisms underlying their control.
Collapse
Affiliation(s)
- Ada Eban-Rothschild
- Department of Psychiatry and Behavioral Sciences, Stanford University, 1201 Welch Road, Stanford, CA 94305, USA.
| | - William J Giardino
- Department of Psychiatry and Behavioral Sciences, Stanford University, 1201 Welch Road, Stanford, CA 94305, USA
| | - Luis de Lecea
- Department of Psychiatry and Behavioral Sciences, Stanford University, 1201 Welch Road, Stanford, CA 94305, USA.
| |
Collapse
|
122
|
Genes and neural circuits for sleep of the fruit fly. Neurosci Res 2017; 118:82-91. [DOI: 10.1016/j.neures.2017.04.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 03/29/2017] [Accepted: 03/29/2017] [Indexed: 02/07/2023]
|
123
|
Regulation of sleep plasticity by a thermo-sensitive circuit in Drosophila. Sci Rep 2017; 7:40304. [PMID: 28084307 PMCID: PMC5233985 DOI: 10.1038/srep40304] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 12/05/2016] [Indexed: 11/29/2022] Open
Abstract
Sleep is a highly conserved and essential behaviour in many species, including the fruit fly Drosophila melanogaster. In the wild, sensory signalling encoding environmental information must be integrated with sleep drive to ensure that sleep is not initiated during detrimental conditions. However, the molecular and circuit mechanisms by which sleep timing is modulated by the environment are unclear. Here we introduce a novel behavioural paradigm to study this issue. We show that in male fruit flies, onset of the daytime siesta is delayed by ambient temperatures above 29 °C. We term this effect Prolonged Morning Wakefulness (PMW). We show that signalling through the TrpA1 thermo-sensor is required for PMW, and that TrpA1 specifically impacts siesta onset, but not night sleep onset, in response to elevated temperatures. We identify two critical TrpA1-expressing circuits and show that both contact DN1p clock neurons, the output of which is also required for PMW. Finally, we identify the circadian blue-light photoreceptor CRYPTOCHROME as a molecular regulator of PMW, and propose a model in which the Drosophila nervous system integrates information encoding temperature, light, and time to dynamically control when sleep is initiated. Our results provide a platform to investigate how environmental inputs co-ordinately regulate sleep plasticity.
Collapse
|
124
|
Ferguson L, Petty A, Rohrscheib C, Troup M, Kirszenblat L, Eyles DW, van Swinderen B. Transient Dysregulation of Dopamine Signaling in a Developing Drosophila Arousal Circuit Permanently Impairs Behavioral Responsiveness in Adults. Front Psychiatry 2017; 8:22. [PMID: 28243212 PMCID: PMC5304146 DOI: 10.3389/fpsyt.2017.00022] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 01/26/2017] [Indexed: 11/13/2022] Open
Abstract
The dopamine ontogeny hypothesis for schizophrenia proposes that transient dysregulation of the dopaminergic system during brain development increases the likelihood of this disorder in adulthood. To test this hypothesis in a high-throughput animal model, we have transiently manipulated dopamine signaling in the developing fruit fly Drosophila melanogaster and examined behavioral responsiveness in adult flies. We found that either a transient increase of dopamine neuron activity or a transient decrease of dopamine receptor expression during fly brain development permanently impairs behavioral responsiveness in adults. A screen for impaired responsiveness revealed sleep-promoting neurons in the central brain as likely postsynaptic dopamine targets modulating these behavioral effects. Transient dopamine receptor knockdown during development in a restricted set of ~20 sleep-promoting neurons recapitulated the dopamine ontogeny phenotype, by permanently reducing responsiveness in adult animals. This suggests that disorders involving impaired behavioral responsiveness might result from defective ontogeny of sleep/wake circuits.
Collapse
Affiliation(s)
- Lachlan Ferguson
- Queensland Brain Institute, The University of Queensland , Brisbane, QLD , Australia
| | - Alice Petty
- Queensland Brain Institute, The University of Queensland , Brisbane, QLD , Australia
| | - Chelsie Rohrscheib
- Queensland Brain Institute, The University of Queensland , Brisbane, QLD , Australia
| | - Michael Troup
- Queensland Brain Institute, The University of Queensland , Brisbane, QLD , Australia
| | - Leonie Kirszenblat
- Queensland Brain Institute, The University of Queensland , Brisbane, QLD , Australia
| | - Darryl W Eyles
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia; Queensland Centre for Mental Health Research, Wacol, QLD, Australia
| | - Bruno van Swinderen
- Queensland Brain Institute, The University of Queensland , Brisbane, QLD , Australia
| |
Collapse
|
125
|
Abstract
Sleep is essential for health and cognition, but the molecular and neural mechanisms of sleep regulation are not well understood. We recently reported the identification of TARANIS (TARA) as a sleep-promoting factor that acts in a previously unknown arousal center in Drosophila. tara mutants exhibit a dose-dependent reduction in sleep amount of up to ∼60%. TARA and its mammalian homologs, the Trip-Br (Transcriptional Regulators Interacting with PHD zinc fingers and/or Bromodomains) family of proteins, are primarily known as transcriptional coregulators involved in cell cycle progression, and contain a conserved Cyclin-A (CycA) binding homology domain. We found that tara and CycA synergistically promote sleep, and CycA levels are reduced in tara mutants. Additional data demonstrated that Cyclin-dependent kinase 1 (Cdk1) antagonizes tara and CycA to promote wakefulness. Moreover, we identified a subset of CycA expressing neurons in the pars lateralis, a brain region proposed to be analogous to the mammalian hypothalamus, as an arousal center. In this Extra View article, we report further characterization of tara mutants and provide an extended discussion of our findings and future directions within the framework of a working model, in which a network of cell cycle genes, tara, CycA, and Cdk1, interact in an arousal center to regulate sleep.
Collapse
Affiliation(s)
- Dinis J S Afonso
- a Department of Neuroscience ; the Farber Institute for Neurosciences; and Kimmel Cancer Center; Thomas Jefferson University ; Philadelphia , PA USA.,b Life and Health Sciences Research Institute (ICVS); School of Health Sciences; University of Minho ; 4710-057 Braga , Portugal.,c ICVS/3B's; PT Government Associate Laboratory ; 4710-057 Braga/Guimarães ; Portugal
| | - Daniel R Machado
- a Department of Neuroscience ; the Farber Institute for Neurosciences; and Kimmel Cancer Center; Thomas Jefferson University ; Philadelphia , PA USA.,b Life and Health Sciences Research Institute (ICVS); School of Health Sciences; University of Minho ; 4710-057 Braga , Portugal.,c ICVS/3B's; PT Government Associate Laboratory ; 4710-057 Braga/Guimarães ; Portugal
| | - Kyunghee Koh
- a Department of Neuroscience ; the Farber Institute for Neurosciences; and Kimmel Cancer Center; Thomas Jefferson University ; Philadelphia , PA USA
| |
Collapse
|
126
|
Neurexin regulates nighttime sleep by modulating synaptic transmission. Sci Rep 2016; 6:38246. [PMID: 27905548 PMCID: PMC5131284 DOI: 10.1038/srep38246] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 11/07/2016] [Indexed: 11/09/2022] Open
Abstract
Neurexins are cell adhesion molecules involved in synaptic formation and synaptic transmission. Mutations in neurexin genes are linked to autism spectrum disorders (ASDs), which are frequently associated with sleep problems. However, the role of neurexin-mediated synaptic transmission in sleep regulation is unclear. Here, we show that lack of the Drosophila α-neurexin homolog significantly reduces the quantity and quality of nighttime sleep and impairs sleep homeostasis. We report that neurexin expression in Drosophila mushroom body (MB) αβ neurons is essential for nighttime sleep. We demonstrate that reduced nighttime sleep in neurexin mutants is due to impaired αβ neuronal output, and show that neurexin functionally couples calcium channels (Cac) to regulate synaptic transmission. Finally, we determine that αβ surface (αβs) neurons release both acetylcholine and short neuropeptide F (sNPF), whereas αβ core (αβc) neurons release sNPF to promote nighttime sleep. Our findings reveal that neurexin regulates nighttime sleep by mediating the synaptic transmission of αβ neurons. This study elucidates the role of synaptic transmission in sleep regulation, and might offer insights into the mechanism of sleep disturbances in patients with autism disorders.
Collapse
|
127
|
Murphy KR, Deshpande SA, Yurgel ME, Quinn JP, Weissbach JL, Keene AC, Dawson-Scully K, Huber R, Tomchik SM, Ja WW. Postprandial sleep mechanics in Drosophila. eLife 2016; 5. [PMID: 27873574 PMCID: PMC5119887 DOI: 10.7554/elife.19334] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Accepted: 10/27/2016] [Indexed: 01/10/2023] Open
Abstract
Food consumption is thought to induce sleepiness. However, little is known about how postprandial sleep is regulated. Here, we simultaneously measured sleep and food intake of individual flies and found a transient rise in sleep following meals. Depending on the amount consumed, the effect ranged from slightly arousing to strongly sleep inducing. Postprandial sleep was positively correlated with ingested volume, protein, and salt—but not sucrose—revealing meal property-specific regulation. Silencing of leucokinin receptor (Lkr) neurons specifically reduced sleep induced by protein consumption. Thermogenetic stimulation of leucokinin (Lk) neurons decreased whereas Lk downregulation by RNAi increased postprandial sleep, suggestive of an inhibitory connection in the Lk-Lkr circuit. We further identified a subset of non-leucokininergic cells proximal to Lkr neurons that rhythmically increased postprandial sleep when silenced, suggesting that these cells are cyclically gated inhibitory inputs to Lkr neurons. Together, these findings reveal the dynamic nature of postprandial sleep. DOI:http://dx.doi.org/10.7554/eLife.19334.001 Many of us have experienced feelings of sleepiness after a large meal. However, there is little scientific evidence that this “food coma” effect is real. If it is, it may vary between individuals, or depend on the type of food consumed. This variability makes it difficult to study the causes of post-meal sleepiness. Murphy et al. have now developed a system that can measure fruit fly sleep and feeding behavior at the same time. Recordings using this system reveal that after a meal, flies sleep more for a short period before returning to a normal state of wakefulness. The sleep period lasts around 20-40 minutes, with flies that ate more generally sleeping more. Further investigation revealed that salty or protein-rich foods promote sleep, whereas sugary foods do not. By using genetic tools to turn on and off neurons in the fly brain, Murphy et al. identified a number of brain circuits that play a role in controlling post-meal sleepiness. Some of these respond specifically to the consumption of protein. Others are sensitive to the fruit fly’s internal clock, reducing post-meal sleepiness only around dusk. Thus, post-meal sleepiness can be regulated in a number of different ways. Future experiments are now needed to explore the genes and circuits that enable meal size and the protein or salt content of food to drive sleep. In nature, sleep is likely a vulnerable state for animals. Thus, another challenge will be to uncover why post-meal sleep is important. Does sleeping after a meal boost digestion? Or might it help animals to form memories about a food source, making it easier to find similar food in the future? DOI:http://dx.doi.org/10.7554/eLife.19334.002
Collapse
Affiliation(s)
- Keith R Murphy
- Department of Metabolism and Aging, The Scripps Research Institute, Jupiter, United States.,Program in Integrative Biology and Neuroscience, Florida Atlantic University, Jupiter, United States.,Department of Neuroscience, The Scripps Research Institute, Jupiter, United States
| | - Sonali A Deshpande
- Department of Metabolism and Aging, The Scripps Research Institute, Jupiter, United States
| | - Maria E Yurgel
- Program in Integrative Biology and Neuroscience, Florida Atlantic University, Jupiter, United States
| | - James P Quinn
- Department of Metabolism and Aging, The Scripps Research Institute, Jupiter, United States
| | - Jennifer L Weissbach
- Department of Metabolism and Aging, The Scripps Research Institute, Jupiter, United States
| | - Alex C Keene
- Program in Integrative Biology and Neuroscience, Florida Atlantic University, Jupiter, United States
| | - Ken Dawson-Scully
- Program in Integrative Biology and Neuroscience, Florida Atlantic University, Jupiter, United States
| | - Robert Huber
- Radcliffe Institute for Advanced Study, Harvard University, Cambridge, United States.,JP Scott Center for Neuroscience, Mind and Behavior, Bowling Green State University, Bowling Green, United States
| | - Seth M Tomchik
- Department of Neuroscience, The Scripps Research Institute, Jupiter, United States
| | - William W Ja
- Department of Metabolism and Aging, The Scripps Research Institute, Jupiter, United States.,Department of Neuroscience, The Scripps Research Institute, Jupiter, United States
| |
Collapse
|
128
|
Kucherenko MM, Ilangovan V, Herzig B, Shcherbata HR, Bringmann H. TfAP-2 is required for night sleep in Drosophila. BMC Neurosci 2016; 17:72. [PMID: 27829368 PMCID: PMC5103423 DOI: 10.1186/s12868-016-0306-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 10/31/2016] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND The AP-2 transcription factor APTF-1 is crucially required for developmentally controlled sleep behavior in Caenorhabditis elegans larvae. Its human ortholog, TFAP-2beta, causes Char disease and has also been linked to sleep disorders. These data suggest that AP-2 transcription factors may be highly conserved regulators of various types of sleep behavior. Here, we tested the idea that AP-2 controls adult sleep in Drosophila. RESULTS Drosophila has one AP-2 ortholog called TfAP-2, which is essential for viability. To investigate its potential role in sleep behavior and neural development, we specifically downregulated TfAP-2 in the nervous system. We found that neuronal TfAP-2 knockdown almost completely abolished night sleep but did not affect day sleep. TfAP-2 insufficiency affected nervous system development. Conditional TfAP-2 knockdown in the adult also produced a modest sleep phenotype, suggesting that TfAP-2 acts both in larval as well as in differentiated neurons. CONCLUSIONS Thus, our results show that AP-2 transcription factors are highly conserved regulators of development and sleep.
Collapse
Affiliation(s)
- Mariya M Kucherenko
- Max Planck Research Group Gene Expression and Signaling, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
| | - Vinodh Ilangovan
- Department of Genes and Behavior, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Bettina Herzig
- Max Planck Research Group Sleep and Waking, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
| | - Halyna R Shcherbata
- Max Planck Research Group Gene Expression and Signaling, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany.
| | - Henrik Bringmann
- Max Planck Research Group Sleep and Waking, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany.
| |
Collapse
|
129
|
Sandman is a Sleep Switch in Drosophila. Neurosci Bull 2016; 32:503-4. [PMID: 27624342 DOI: 10.1007/s12264-016-0062-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Accepted: 08/30/2016] [Indexed: 10/21/2022] Open
|
130
|
Chen J, Reiher W, Hermann-Luibl C, Sellami A, Cognigni P, Kondo S, Helfrich-Förster C, Veenstra JA, Wegener C. Allatostatin A Signalling in Drosophila Regulates Feeding and Sleep and Is Modulated by PDF. PLoS Genet 2016; 12:e1006346. [PMID: 27689358 PMCID: PMC5045179 DOI: 10.1371/journal.pgen.1006346] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 09/07/2016] [Indexed: 11/19/2022] Open
Abstract
Feeding and sleep are fundamental behaviours with significant interconnections and cross-modulations. The circadian system and peptidergic signals are important components of this modulation, but still little is known about the mechanisms and networks by which they interact to regulate feeding and sleep. We show that specific thermogenetic activation of peptidergic Allatostatin A (AstA)-expressing PLP neurons and enteroendocrine cells reduces feeding and promotes sleep in the fruit fly Drosophila. The effects of AstA cell activation are mediated by AstA peptides with receptors homolog to galanin receptors subserving similar and apparently conserved functions in vertebrates. We further identify the PLP neurons as a downstream target of the neuropeptide pigment-dispersing factor (PDF), an output factor of the circadian clock. PLP neurons are contacted by PDF-expressing clock neurons, and express a functional PDF receptor demonstrated by cAMP imaging. Silencing of AstA signalling and continuous input to AstA cells by tethered PDF changes the sleep/activity ratio in opposite directions but does not affect rhythmicity. Taken together, our results suggest that pleiotropic AstA signalling by a distinct neuronal and enteroendocrine AstA cell subset adapts the fly to a digestive energy-saving state which can be modulated by PDF.
Collapse
Affiliation(s)
- Jiangtian Chen
- Neurobiology and Genetics, Theodor-Boveri-Institute, Biocenter, University of Würzburg, Würzburg, Germany
| | - Wencke Reiher
- Neurobiology and Genetics, Theodor-Boveri-Institute, Biocenter, University of Würzburg, Würzburg, Germany
| | - Christiane Hermann-Luibl
- Neurobiology and Genetics, Theodor-Boveri-Institute, Biocenter, University of Würzburg, Würzburg, Germany
| | - Azza Sellami
- INCIA, UMR 5287 CNRS, University of Bordeaux, Talence, France
| | - Paola Cognigni
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
| | - Shu Kondo
- Genetic Strains Research Center, National Institute of Genetics, Shizuoka, Japan
| | - Charlotte Helfrich-Förster
- Neurobiology and Genetics, Theodor-Boveri-Institute, Biocenter, University of Würzburg, Würzburg, Germany
| | - Jan A. Veenstra
- INCIA, UMR 5287 CNRS, University of Bordeaux, Talence, France
| | - Christian Wegener
- Neurobiology and Genetics, Theodor-Boveri-Institute, Biocenter, University of Würzburg, Würzburg, Germany
| |
Collapse
|
131
|
Pimentel D, Donlea JM, Talbot CB, Song SM, Thurston AJF, Miesenböck G. Operation of a homeostatic sleep switch. Nature 2016; 536:333-337. [PMID: 27487216 PMCID: PMC4998959 DOI: 10.1038/nature19055] [Citation(s) in RCA: 160] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 06/24/2016] [Indexed: 01/18/2023]
Abstract
Sleep disconnects animals from the external world, at considerable risks and costs that must be offset by a vital benefit. Insight into this mysterious benefit will come from understanding sleep homeostasis: to monitor sleep need, an internal bookkeeper must track physiological changes that are linked to the core function of sleep. In Drosophila, a crucial component of the machinery for sleep homeostasis is a cluster of neurons innervating the dorsal fan-shaped body (dFB) of the central complex. Artificial activation of these cells induces sleep, whereas reductions in excitability cause insomnia. dFB neurons in sleep-deprived flies tend to be electrically active, with high input resistances and long membrane time constants, while neurons in rested flies tend to be electrically silent. Correlative evidence thus supports the simple view that homeostatic sleep control works by switching sleep-promoting neurons between active and quiescent states. Here we demonstrate state switching by dFB neurons, identify dopamine as a neuromodulator that operates the switch, and delineate the switching mechanism. Arousing dopamine caused transient hyperpolarization of dFB neurons within tens of milliseconds and lasting excitability suppression within minutes. Both effects were transduced by Dop1R2 receptors and mediated by potassium conductances. The switch to electrical silence involved the downregulation of voltage-gated A-type currents carried by Shaker and Shab, and the upregulation of voltage-independent leak currents through a two-pore-domain potassium channel that we term Sandman. Sandman is encoded by the CG8713 gene and translocates to the plasma membrane in response to dopamine. dFB-restricted interference with the expression of Shaker or Sandman decreased or increased sleep, respectively, by slowing the repetitive discharge of dFB neurons in the ON state or blocking their entry into the OFF state. Biophysical changes in a small population of neurons are thus linked to the control of sleep-wake state.
Collapse
Affiliation(s)
- Diogo Pimentel
- Centre for Neural Circuits and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford, OX1 3SR, United Kingdom
| | - Jeffrey M Donlea
- Centre for Neural Circuits and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford, OX1 3SR, United Kingdom
| | - Clifford B Talbot
- Centre for Neural Circuits and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford, OX1 3SR, United Kingdom
| | - Seoho M Song
- Centre for Neural Circuits and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford, OX1 3SR, United Kingdom
| | - Alexander J F Thurston
- Centre for Neural Circuits and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford, OX1 3SR, United Kingdom
| | - Gero Miesenböck
- Centre for Neural Circuits and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford, OX1 3SR, United Kingdom
| |
Collapse
|
132
|
Abstract
Sleep disorders in humans are increasingly appreciated to be not only widespread but also detrimental to multiple facets of physical and mental health. Recent work has begun to shed light on the mechanistic basis of sleep disorders like insomnia, restless legs syndrome, narcolepsy, and a host of others, but a more detailed genetic and molecular understanding of how sleep goes awry is lacking. Over the past 15 years, studies in Drosophila have yielded new insights into basic questions regarding sleep function and regulation. More recently, powerful genetic approaches in the fly have been applied toward studying primary human sleep disorders and other disease states associated with dysregulated sleep. In this review, we discuss the contribution of Drosophila to the landscape of sleep biology, examining not only fundamental advances in sleep neurobiology but also how flies have begun to inform pathological sleep states in humans.
Collapse
|
133
|
Lymer S, Blau J. Do Flies Count Sheep or NMDA Receptors to Go to Sleep? Cell 2016; 165:1310-1311. [PMID: 27259141 DOI: 10.1016/j.cell.2016.05.059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The drive to sleep increases the longer that we stay awake, but this process is poorly understood at the cellular level. Now, Liu et al. show that the plasticity of a small group of neurons in the Drosophila central brain is a key component of the sleep homeostat.
Collapse
Affiliation(s)
- Seana Lymer
- Department of Biology, New York University, 100 Washington Square East, New York, NY 10003, USA
| | - Justin Blau
- Department of Biology, New York University, 100 Washington Square East, New York, NY 10003, USA; Center for Genomics & Systems Biology, New York University Abu Dhabi Institute, Abu Dhabi, United Arab Emirates; Program in Biology, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates.
| |
Collapse
|
134
|
de Bivort BL, van Swinderen B. Evidence for selective attention in the insect brain. CURRENT OPINION IN INSECT SCIENCE 2016; 15:9-15. [PMID: 27436727 DOI: 10.1016/j.cois.2016.02.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 02/10/2016] [Accepted: 02/15/2016] [Indexed: 06/06/2023]
Abstract
The capacity for selective attention appears to be required by any animal responding to an environment containing multiple objects, although this has been difficult to study in smaller animals such as insects. Clear operational characteristics of attention however make study of this crucial brain function accessible to any animal model. Whereas earlier approaches have relied on freely behaving paradigms placed in an ecologically relevant context, recent tethered preparations have focused on brain imaging and electrophysiology in virtual reality environments. Insight into brain activity during attention-like behavior has revealed key elements of attention in the insect brain. Surprisingly, a variety of brain structures appear to be involved, suggesting that even in the smallest brains attention might involve widespread coordination of neural activity.
Collapse
Affiliation(s)
- Benjamin L de Bivort
- Center for Brain Science and Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Bruno van Swinderen
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia.
| |
Collapse
|
135
|
Sleep Homeostasis and General Anesthesia: Are Fruit Flies Well Rested after Emergence from Propofol? Anesthesiology 2016; 124:404-16. [PMID: 26556728 DOI: 10.1097/aln.0000000000000939] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND Shared neurophysiologic features between sleep and anesthetic-induced hypnosis indicate a potential overlap in neuronal circuitry underlying both states. Previous studies in rodents indicate that preexisting sleep debt discharges under propofol anesthesia. The authors explored the hypothesis that propofol anesthesia also dispels sleep pressure in the fruit fly. To the authors' knowledge, this constitutes the first time propofol has been tested in the genetically tractable model, Drosophila melanogaster. METHODS Daily sleep was measured in Drosophila by using a standard locomotor activity assay. Propofol was administered by transferring flies onto food containing various doses of propofol or equivalent concentrations of vehicle. High-performance liquid chromatography was used to measure the tissue concentrations of ingested propofol. To determine whether propofol anesthesia substitutes for natural sleep, the flies were subjected to 10-h sleep deprivation (SD), followed by 6-h propofol exposure, and monitored for subsequent sleep. RESULTS Oral propofol treatment causes anesthesia in flies as indicated by a dose-dependent reduction in locomotor activity (n = 11 to 41 flies from each group) and increased arousal threshold (n = 79 to 137). Recovery sleep in flies fed propofol after SD was delayed until after flies had emerged from anesthesia (n = 30 to 48). SD was also associated with a significant increase in mortality in propofol-fed flies (n = 44 to 46). CONCLUSIONS Together, these data indicate that fruit flies are effectively anesthetized by ingestion of propofol and suggest that homologous molecular and neuronal targets of propofol are conserved in Drosophila. However, behavioral measurements indicate that propofol anesthesia does not satisfy the homeostatic need for sleep and may compromise the restorative properties of sleep.
Collapse
|
136
|
Liu S, Liu Q, Tabuchi M, Wu MN. Sleep Drive Is Encoded by Neural Plastic Changes in a Dedicated Circuit. Cell 2016; 165:1347-1360. [PMID: 27212237 DOI: 10.1016/j.cell.2016.04.013] [Citation(s) in RCA: 202] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 03/04/2016] [Accepted: 04/04/2016] [Indexed: 12/20/2022]
Abstract
Prolonged wakefulness leads to an increased pressure for sleep, but how this homeostatic drive is generated and subsequently persists is unclear. Here, from a neural circuit screen in Drosophila, we identify a subset of ellipsoid body (EB) neurons whose activation generates sleep drive. Patch-clamp analysis indicates these EB neurons are highly sensitive to sleep loss, switching from spiking to burst-firing modes. Functional imaging and translational profiling experiments reveal that elevated sleep need triggers reversible increases in cytosolic Ca(2+) levels, NMDA receptor expression, and structural markers of synaptic strength, suggesting these EB neurons undergo "sleep-need"-dependent plasticity. Strikingly, the synaptic plasticity of these EB neurons is both necessary and sufficient for generating sleep drive, indicating that sleep pressure is encoded by plastic changes within this circuit. These studies define an integrator circuit for sleep homeostasis and provide a mechanism explaining the generation and persistence of sleep drive.
Collapse
Affiliation(s)
- Sha Liu
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Qili Liu
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Masashi Tabuchi
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Mark N Wu
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21287, USA; Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21287, USA.
| |
Collapse
|
137
|
Dubowy C, Moravcevic K, Yue Z, Wan JY, Van Dongen HP, Sehgal A. Genetic Dissociation of Daily Sleep and Sleep Following Thermogenetic Sleep Deprivation in Drosophila. Sleep 2016; 39:1083-95. [PMID: 26951392 PMCID: PMC4835307 DOI: 10.5665/sleep.5760] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 01/11/2016] [Indexed: 12/23/2022] Open
Abstract
STUDY OBJECTIVES Sleep rebound-the increase in sleep that follows sleep deprivation-is a hallmark of homeostatic sleep regulation that is conserved across the animal kingdom. However, both the mechanisms that underlie sleep rebound and its relationship to habitual daily sleep remain unclear. To address this, we developed an efficient thermogenetic method of inducing sleep deprivation in Drosophila that produces a substantial rebound, and applied the newly developed method to assess sleep rebound in a screen of 1,741 mutated lines. We used data generated by this screen to identify lines with reduced sleep rebound following thermogenetic sleep deprivation, and to probe the relationship between habitual sleep amount and sleep following thermogenetic sleep deprivation in Drosophila. METHODS To develop a thermogenetic method of sleep deprivation suitable for screening, we thermogenetically stimulated different populations of wake-promoting neurons labeled by Gal4 drivers. Sleep rebound following thermogenetically-induced wakefulness varies across the different sets of wake-promoting neurons that were stimulated, from very little to quite substantial. Thermogenetic activation of neurons marked by the c584-Gal4 driver produces both strong sleep loss and a substantial rebound that is more consistent within genotypes than rebound following mechanical or caffeine-induced sleep deprivation. We therefore used this driver to induce sleep deprivation in a screen of 1,741 mutagenized lines generated by the Drosophila Gene Disruption Project. Flies were subjected to 9 h of sleep deprivation during the dark period and released from sleep deprivation 3 h before lights-on. Recovery was measured over the 15 h following sleep deprivation. Following identification of lines with reduced sleep rebound, we characterized baseline sleep and sleep depth before and after sleep deprivation for these hits. RESULTS We identified two lines that consistently exhibit a blunted increase in the duration and depth of sleep after thermogenetic sleep deprivation. Neither of the two genotypes has reduced total baseline sleep. Statistical analysis across all screened lines shows that genotype is a strong predictor of recovery sleep, independent from effects of genotype on baseline sleep. CONCLUSIONS Our data show that rebound sleep following thermogenetic sleep deprivation can be genetically separated from sleep at baseline. This suggests that genetically controlled mechanisms of sleep regulation not manifest under undisturbed conditions contribute to sleep rebound following thermogenetic sleep deprivation.
Collapse
Affiliation(s)
- Christine Dubowy
- Cell and Molecular Biology Graduate Group, Biomedical Graduate Studies, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Katarina Moravcevic
- Department of Neuroscience, HHMI, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Zhifeng Yue
- Department of Neuroscience, HHMI, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Joy Y. Wan
- Department of Neuroscience, HHMI, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Hans P.A. Van Dongen
- Sleep and Performance Research Center and Elson S. Floyd College of Medicine, Washington State University, Spokane, WA
| | - Amita Sehgal
- Department of Neuroscience, HHMI, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| |
Collapse
|
138
|
Cavanaugh DJ, Vigderman AS, Dean T, Garbe DS, Sehgal A. The Drosophila Circadian Clock Gates Sleep through Time-of-Day Dependent Modulation of Sleep-Promoting Neurons. Sleep 2016; 39:345-56. [PMID: 26350473 DOI: 10.5665/sleep.5442] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 08/12/2015] [Indexed: 01/20/2023] Open
Abstract
STUDY OBJECTIVES Sleep is under the control of homeostatic and circadian processes, which interact to determine sleep timing and duration, but the mechanisms through which the circadian system modulates sleep are largely unknown. We therefore used adult-specific, temporally controlled neuronal activation and inhibition to identify an interaction between the circadian clock and a novel population of sleep-promoting neurons in Drosophila. METHODS Transgenic flies expressed either dTRPA1, a neuronal activator, or Shibire(ts1), an inhibitor of synaptic release, in small subsets of neurons. Sleep, as determined by activity monitoring and video tracking, was assessed before and after temperature-induced activation or inhibition using these effector molecules. We compared the effect of these manipulations in control flies and in mutant flies that lacked components of the molecular circadian clock. RESULTS Adult-specific activation or inhibition of a population of neurons that projects to the sleep-promoting dorsal Fan-Shaped Body resulted in bidirectional control over sleep. Interestingly, the magnitude of the sleep changes were time-of-day dependent. Activation of sleep-promoting neurons was maximally effective during the middle of the day and night, and was relatively ineffective during the day-to-night and night-to-day transitions. These time-ofday specific effects were absent in flies that lacked functional circadian clocks. CONCLUSIONS We conclude that the circadian system functions to gate sleep through active inhibition at specific times of day. These data identify a mechanism through which the circadian system prevents premature sleep onset in the late evening, when homeostatic sleep drive is high.
Collapse
Affiliation(s)
- Daniel J Cavanaugh
- Penn Chronobiology Program, Philadelphia PA.,Current Address: Department of Biology, Loyola University Chicago, Chicago IL
| | | | - Terry Dean
- Penn Chronobiology Program, Philadelphia PA
| | | | - Amita Sehgal
- Penn Chronobiology Program, Philadelphia PA.,Howard Hughes Medical Institute, University of Pennsylvania, Philadelphia PA
| |
Collapse
|
139
|
A Conserved GEF for Rho-Family GTPases Acts in an EGF Signaling Pathway to Promote Sleep-like Quiescence in Caenorhabditis elegans. Genetics 2016; 202:1153-66. [PMID: 26801183 DOI: 10.1534/genetics.115.183038] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 01/18/2016] [Indexed: 11/18/2022] Open
Abstract
Sleep is evolutionarily conserved and required for organism homeostasis and survival. Despite this importance, the molecular and cellular mechanisms underlying sleep are not well understood. Caenorhabditis elegans exhibits sleep-like behavioral quiescence and thus provides a valuable, simple model system for the study of cellular and molecular regulators of this process. In C. elegans, epidermal growth factor receptor (EGFR) signaling is required in the neurosecretory neuron ALA to promote sleep-like behavioral quiescence after cellular stress. We describe a novel role for VAV-1, a conserved guanine nucleotide exchange factor (GEF) for Rho-family GTPases, in regulation of sleep-like behavioral quiescence. VAV-1, in a GEF-dependent manner, acts in ALA to suppress locomotion and feeding during sleep-like behavioral quiescence in response to cellular stress. Additionally, VAV-1 activity is required for EGF-induced sleep-like quiescence and normal levels of EGFR and secretory dense core vesicles in ALA. Importantly, the role of VAV-1 in promoting cellular stress-induced behavioral quiescence is vital for organism health because VAV-1 is required for normal survival after cellular stress.
Collapse
|
140
|
Andretić R. Neurobiology: What Drives Flies to Sleep? Curr Biol 2015; 25:R1086-8. [PMID: 26583901 DOI: 10.1016/j.cub.2015.08.062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The number of wake-promoting neurons in the Drosophila brain is relatively small, and only some of them have the unique ability to promote robust recovery sleep following wakefulness.
Collapse
Affiliation(s)
- Rozi Andretić
- Department of Biotechnology, University of Rijeka, R. Matejcic 2, 51000 Rijeka, Croatia.
| |
Collapse
|
141
|
Sitaraman D, Aso Y, Rubin GM, Nitabach MN. Control of Sleep by Dopaminergic Inputs to the Drosophila Mushroom Body. Front Neural Circuits 2015; 9:73. [PMID: 26617493 PMCID: PMC4637407 DOI: 10.3389/fncir.2015.00073] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 10/23/2015] [Indexed: 01/08/2023] Open
Abstract
The Drosophila mushroom body (MB) is an associative learning network that is important for the control of sleep. We have recently identified particular intrinsic MB Kenyon cell (KC) classes that regulate sleep through synaptic activation of particular MB output neurons (MBONs) whose axons convey sleep control signals out of the MB to downstream target regions. Specifically, we found that sleep-promoting KCs increase sleep by preferentially activating cholinergic sleep-promoting MBONs, while wake-promoting KCs decrease sleep by preferentially activating glutamatergic wake-promoting MBONs. Here we use a combination of genetic and physiological approaches to identify wake-promoting dopaminergic neurons (DANs) that innervate the MB, and show that they activate wake-promoting MBONs. These studies reveal a dopaminergic sleep control mechanism that likely operates by modulation of KC-MBON microcircuits.
Collapse
Affiliation(s)
- Divya Sitaraman
- Department of Cellular and Molecular Physiology, Yale University School of Medicine New Haven, CT, USA ; Janelia Research Campus, Howard Hughes Medical Institute Ashburn, VA, USA
| | - Yoshinori Aso
- Janelia Research Campus, Howard Hughes Medical Institute Ashburn, VA, USA
| | - Gerald M Rubin
- Janelia Research Campus, Howard Hughes Medical Institute Ashburn, VA, USA
| | - Michael N Nitabach
- Department of Cellular and Molecular Physiology, Yale University School of Medicine New Haven, CT, USA ; Janelia Research Campus, Howard Hughes Medical Institute Ashburn, VA, USA ; Department of Genetics, Yale University School of Medicine New Haven, CT, USA ; Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine New Haven, CT, USA
| |
Collapse
|
142
|
Seidner G, Robinson JE, Wu M, Worden K, Masek P, Roberts SW, Keene AC, Joiner WJ. Identification of Neurons with a Privileged Role in Sleep Homeostasis in Drosophila melanogaster. Curr Biol 2015; 25:2928-38. [PMID: 26526372 DOI: 10.1016/j.cub.2015.10.006] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 09/25/2015] [Accepted: 10/02/2015] [Indexed: 12/17/2022]
Abstract
Sleep is thought to be controlled by two main processes: a circadian clock that primarily regulates sleep timing and a homeostatic mechanism that detects and responds to sleep need. Whereas abundant experimental evidence suggests that sleep need increases with time spent awake, the contributions of different brain arousal systems have not been assessed independently of each other to determine whether certain neural circuits, rather than waking per se, selectively contribute to sleep homeostasis. Using the fruit fly, Drosophila melanogaster, we found that sustained thermogenetic activation of three independent neurotransmitter systems promoted nighttime wakefulness. However, only sleep deprivation resulting from activation of cholinergic neurons was sufficient to elicit subsequent homeostatic recovery sleep, as assessed by multiple behavioral criteria. In contrast, sleep deprivation resulting from activation of octopaminergic neurons suppressed homeostatic recovery sleep, indicating that wakefulness can be dissociated from accrual of sleep need. Neurons that promote sleep homeostasis were found to innervate the central brain and motor control regions of the thoracic ganglion. Blocking activity of these neurons suppressed recovery sleep but did not alter baseline sleep, further differentiating between neural control of sleep homeostasis and daily fluctuations in the sleep/wake cycle. Importantly, selective activation of wake-promoting neurons without engaging the sleep homeostat impaired subsequent short-term memory, thus providing evidence that neural circuits that regulate sleep homeostasis are important for behavioral plasticity. Together, our data suggest a neural circuit model involving distinct populations of wake-promoting neurons, some of which are involved in homeostatic control of sleep and cognition.
Collapse
Affiliation(s)
- Glen Seidner
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093, USA
| | - James E Robinson
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093, USA; Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, CA 92093, USA
| | - Meilin Wu
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093, USA
| | - Kurtresha Worden
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Pavel Masek
- Department of Biological Sciences, Binghamton University, Binghamton, NY 13902, USA
| | - Stephen W Roberts
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, CA 92093, USA
| | - Alex C Keene
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL 33458, USA
| | - William J Joiner
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093, USA; Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, CA 92093, USA; Neurosciences Graduate Program, University of California San Diego, La Jolla, CA 92093, USA; Center for Circadian Biology, University of California San Diego, La Jolla, CA 92093, USA.
| |
Collapse
|
143
|
Sitaraman D, Aso Y, Jin X, Chen N, Felix M, Rubin GM, Nitabach MN. Propagation of Homeostatic Sleep Signals by Segregated Synaptic Microcircuits of the Drosophila Mushroom Body. Curr Biol 2015; 25:2915-27. [PMID: 26455303 DOI: 10.1016/j.cub.2015.09.017] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 08/12/2015] [Accepted: 09/04/2015] [Indexed: 12/17/2022]
Abstract
The Drosophila mushroom body (MB) is a key associative memory center that has also been implicated in the control of sleep. However, the identity of MB neurons underlying homeostatic sleep regulation, as well as the types of sleep signals generated by specific classes of MB neurons, has remained poorly understood. We recently identified two MB output neuron (MBON) classes whose axons convey sleep control signals from the MB to converge in the same downstream target region: a cholinergic sleep-promoting MBON class and a glutamatergic wake-promoting MBON class. Here, we deploy a combination of neurogenetic, behavioral, and physiological approaches to identify and mechanistically dissect sleep-controlling circuits of the MB. Our studies reveal the existence of two segregated excitatory synaptic microcircuits that propagate homeostatic sleep information from different populations of intrinsic MB "Kenyon cells" (KCs) to specific sleep-regulating MBONs: sleep-promoting KCs increase sleep by preferentially activating the cholinergic MBONs, while wake-promoting KCs decrease sleep by preferentially activating the glutamatergic MBONs. Importantly, activity of the sleep-promoting MB microcircuit is increased by sleep deprivation and is necessary for homeostatic rebound sleep (i.e., the increased sleep that occurs after, and in compensation for, sleep lost during deprivation). These studies reveal for the first time specific functional connections between subsets of KCs and particular MBONs and establish the identity of synaptic microcircuits underlying transmission of homeostatic sleep signals in the MB.
Collapse
Affiliation(s)
- Divya Sitaraman
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA; Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Yoshinori Aso
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Xin Jin
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Nan Chen
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Mario Felix
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Gerald M Rubin
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Michael N Nitabach
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA; Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA; Department of Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA; Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA.
| |
Collapse
|
144
|
Petruccelli E, Lansdon P, Kitamoto T. Exaggerated Nighttime Sleep and Defective Sleep Homeostasis in a Drosophila Knock-In Model of Human Epilepsy. PLoS One 2015; 10:e0137758. [PMID: 26361221 PMCID: PMC4567262 DOI: 10.1371/journal.pone.0137758] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 08/20/2015] [Indexed: 01/17/2023] Open
Abstract
Despite an established link between epilepsy and sleep behavior, it remains unclear how specific epileptogenic mutations affect sleep and subsequently influence seizure susceptibility. Recently, Sun et al. (2012) created a fly knock-in model of human generalized epilepsy with febrile seizures plus (GEFS+), a wide-spectrum disorder characterized by fever-associated seizing in childhood and lifelong affliction. GEFS+ flies carry a disease-causing mutation in their voltage-gated sodium channel (VGSC) gene and display semidominant heat-induced seizing, likely due to reduced GABAergic inhibitory activity at high temperature. Here, we show that at room temperature the GEFS+ mutation dominantly modifies sleep, with mutants exhibiting rapid sleep onset at dusk and increased nighttime sleep as compared to controls. These characteristics of GEFS+ sleep were observed regardless of sex, mating status, and genetic background. GEFS+ mutant sleep phenotypes were more resistant to pharmacologic reduction of GABA transmission by carbamazepine (CBZ) than controls, and were mitigated by reducing GABAA receptor expression specifically in wake-promoting pigment dispersing factor (PDF) neurons. These findings are consistent with increased GABAergic transmission to PDF neurons being mainly responsible for the enhanced nighttime sleep of GEFS+ mutants. Additionally, analyses under other light conditions suggested that the GEFS+ mutation led to reduced buffering of behavioral responses to light on and off stimuli, which contributed to characteristic GEFS+ sleep phenotypes. We further found that GEFS+ mutants had normal circadian rhythms in free-running dark conditions. Interestingly, the mutants lacked a homeostatic rebound following mechanical sleep deprivation, and whereas deprivation treatment increased heat-induced seizure susceptibility in control flies, it unexpectedly reduced seizure activity in GEFS+ mutants. Our study has revealed the sleep architecture of a Drosophila VGSC mutant that harbors a human GEFS+ mutation, and provided unique insight into the relationship between sleep and epilepsy.
Collapse
Affiliation(s)
- Emily Petruccelli
- Interdisciplinary Program in Genetics, University of Iowa, Iowa City, IA, United States of America
| | - Patrick Lansdon
- Interdisciplinary Program in Genetics, University of Iowa, Iowa City, IA, United States of America
| | - Toshihiro Kitamoto
- Interdisciplinary Program in Genetics, University of Iowa, Iowa City, IA, United States of America
- Department of Anesthesia, Carver College of Medicine, University of Iowa, Iowa City, IA, United States of America
- * E-mail:
| |
Collapse
|
145
|
Hara Y, Koganezawa M, Yamamoto D. TheDmca1Dchannel mediates Ca2+inward currents inDrosophilaembryonic muscles. J Neurogenet 2015; 29:117-23. [DOI: 10.3109/01677063.2015.1054991] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
146
|
Berry JA, Cervantes-Sandoval I, Chakraborty M, Davis RL. Sleep Facilitates Memory by Blocking Dopamine Neuron-Mediated Forgetting. Cell 2015; 161:1656-67. [PMID: 26073942 DOI: 10.1016/j.cell.2015.05.027] [Citation(s) in RCA: 148] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 02/27/2015] [Accepted: 04/20/2015] [Indexed: 01/10/2023]
Abstract
Early studies from psychology suggest that sleep facilitates memory retention by stopping ongoing retroactive interference caused by mental activity or external sensory stimuli. Neuroscience research with animal models, on the other hand, suggests that sleep facilitates retention by enhancing memory consolidation. Recently, in Drosophila, the ongoing activity of specific dopamine neurons was shown to regulate the forgetting of olfactory memories. Here, we show this ongoing dopaminergic activity is modulated with behavioral state, increasing robustly with locomotor activity and decreasing with rest. Increasing sleep-drive, with either the sleep-promoting agent Gaboxadol or by genetic stimulation of the neural circuit for sleep, decreases ongoing dopaminergic activity, while enhancing memory retention. Conversely, increasing arousal stimulates ongoing dopaminergic activity and accelerates dopaminergic-based forgetting. Therefore, forgetting is regulated by the behavioral state modulation of dopaminergic-based plasticity. Our findings integrate psychological and neuroscience research on sleep and forgetting.
Collapse
Affiliation(s)
- Jacob A Berry
- Department of Neuroscience, Scripps Research Institute Florida, Jupiter, FL 33458, USA
| | | | - Molee Chakraborty
- Department of Neuroscience, Scripps Research Institute Florida, Jupiter, FL 33458, USA
| | - Ronald L Davis
- Department of Neuroscience, Scripps Research Institute Florida, Jupiter, FL 33458, USA.
| |
Collapse
|
147
|
Tabuchi M, Lone SR, Liu S, Liu Q, Zhang J, Spira AP, Wu MN. Sleep interacts with aβ to modulate intrinsic neuronal excitability. Curr Biol 2015; 25:702-712. [PMID: 25754641 PMCID: PMC4366315 DOI: 10.1016/j.cub.2015.01.016] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 12/05/2014] [Accepted: 01/06/2015] [Indexed: 12/11/2022]
Abstract
BACKGROUND Emerging data suggest an important relationship between sleep and Alzheimer's disease (AD), but how poor sleep promotes the development of AD remains unclear. RESULTS Here, using a Drosophila model of AD, we provide evidence suggesting that changes in neuronal excitability underlie the effects of sleep loss on AD pathogenesis. β-amyloid (Aβ) accumulation leads to reduced and fragmented sleep, while chronic sleep deprivation increases Aβ burden. Moreover, enhancing sleep reduces Aβ deposition. Increasing neuronal excitability phenocopies the effects of reducing sleep on Aβ, and decreasing neuronal activity blocks the elevated Aβ accumulation induced by sleep deprivation. At the single neuron level, we find that chronic sleep deprivation, as well as Aβ expression, enhances intrinsic neuronal excitability. Importantly, these data reveal that sleep loss exacerbates Aβ-induced hyperexcitability and suggest that defects in specific K(+) currents underlie the hyperexcitability caused by sleep loss and Aβ expression. Finally, we show that feeding levetiracetam, an anti-epileptic medication, to Aβ-expressing flies suppresses neuronal excitability and significantly prolongs their lifespan. CONCLUSIONS Our findings directly link sleep loss to changes in neuronal excitability and Aβ accumulation and further suggest that neuronal hyperexcitability is an important mediator of Aβ toxicity. Taken together, these data provide a mechanistic framework for a positive feedback loop, whereby sleep loss and neuronal excitation accelerate the accumulation of Aβ, a key pathogenic step in the development of AD.
Collapse
Affiliation(s)
- Masashi Tabuchi
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Shahnaz R Lone
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Sha Liu
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Qili Liu
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Julia Zhang
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Adam P Spira
- Department of Mental Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Mark N Wu
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA; Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21205, USA.
| |
Collapse
|
148
|
Ueno T, Kume K. [Sleep research with fruit fly]. Nihon Yakurigaku Zasshi 2015; 145:134-9. [PMID: 25765495 DOI: 10.1254/fpj.145.134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
149
|
Abstract
Brain glial cells, in particular astrocytes and microglia, secrete signaling molecules that regulate glia-glia or glia-neuron communication and synaptic activity. While much is known about roles of glial cells in nervous system development, we are only beginning to understand the physiological functions of such cells in the adult brain. Studies in vertebrate and invertebrate models, in particular mice and Drosophila, have revealed roles of glia-neuron communication in the modulation of complex behavior. This chapter emphasizes recent evidence from studies of rodents and Drosophila that highlight the importance of glial cells and similarities or differences in the neural circuits regulating circadian rhythms and sleep in the two models. The chapter discusses cellular, molecular, and genetic approaches that have been useful in these models for understanding how glia-neuron communication contributes to the regulation of rhythmic behavior.
Collapse
Affiliation(s)
- F Rob Jackson
- Department of Neuroscience, Sackler Program in Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA.
| | - Fanny S Ng
- Department of Neuroscience, Sackler Program in Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA
| | - Sukanya Sengupta
- Department of Neuroscience, Sackler Program in Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA
| | - Samantha You
- Department of Neuroscience, Sackler Program in Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA
| | - Yanmei Huang
- Department of Neuroscience, Sackler Program in Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA
| |
Collapse
|
150
|
Wolff T, Iyer NA, Rubin GM. Neuroarchitecture and neuroanatomy of the Drosophila central complex: A GAL4-based dissection of protocerebral bridge neurons and circuits. J Comp Neurol 2014; 523:997-1037. [PMID: 25380328 PMCID: PMC4407839 DOI: 10.1002/cne.23705] [Citation(s) in RCA: 178] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 10/27/2014] [Accepted: 10/30/2014] [Indexed: 12/11/2022]
Abstract
Insects exhibit an elaborate repertoire of behaviors in response to environmental stimuli. The central complex plays a key role in combining various modalities of sensory information with an insect's internal state and past experience to select appropriate responses. Progress has been made in understanding the broad spectrum of outputs from the central complex neuropils and circuits involved in numerous behaviors. Many resident neurons have also been identified. However, the specific roles of these intricate structures and the functional connections between them remain largely obscure. Significant gains rely on obtaining a comprehensive catalog of the neurons and associated GAL4 lines that arborize within these brain regions, and on mapping neuronal pathways connecting these structures. To this end, small populations of neurons in the Drosophila melanogaster central complex were stochastically labeled using the multicolor flip-out technique and a catalog was created of the neurons, their morphologies, trajectories, relative arrangements, and corresponding GAL4 lines. This report focuses on one structure of the central complex, the protocerebral bridge, and identifies just 17 morphologically distinct cell types that arborize in this structure. This work also provides new insights into the anatomical structure of the four components of the central complex and its accessory neuropils. Most strikingly, we found that the protocerebral bridge contains 18 glomeruli, not 16, as previously believed. Revised wiring diagrams that take into account this updated architectural design are presented. This updated map of the Drosophila central complex will facilitate a deeper behavioral and physiological dissection of this sophisticated set of structures. J. Comp. Neurol. 523:997–1037, 2015. © 2014 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Tanya Wolff
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, 20147
| | | | | |
Collapse
|