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Zhang J, Brown EB, Lloyd E, Farhy-Tselnicker I, Keene AC. Sleep rescues age-associated loss of glial engulfment. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2025.04.02.646667. [PMID: 40236052 PMCID: PMC11996563 DOI: 10.1101/2025.04.02.646667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 04/17/2025]
Abstract
Neuronal injury due to trauma or neurodegeneration is a common feature of aging. The clearance of damaged neurons by glia is thought to be critical for maintenance of proper brain function. Sleep loss has been shown to inhibit the motility and function of glia that clear damaged axons while enhancement of sleep promotes clearance of damaged axons. Despite the potential role of glia in maintenance of brain function and protection against neurodegenerative disease, surprisingly little is known about how sleep loss impacts glial function in aged animals. Axotomy of the Drosophila antennae triggers Wallerian degeneration, where specialized olfactory ensheathing glia engulf damaged neurites. This glial response provides a robust model system to investigate the molecular basis for glial engulfment and neuron-glia communication. Glial engulfment is impaired in aged and sleep-deprived animals, raising the possibility that age-related sleep loss underlies deficits in glial function. To define the relationship between sleep- and age-dependent reductions in glial function, we restored sleep to aged animals and examined the effects on glial clearance of damaged axons. Both pharmacological and genetic induction of sleep restores clearance of damaged neurons in aged flies. Further analysis revealed that sleep restored post-injury induction of the engulfment protein Draper to aged flies, fortifying the notion that loss of sleep contributes to reduced glial-mediated debris clearance in aged animals. To identify age-related changes in the transcriptional response to neuronal injury, we used single-nucleus RNA-seq of the central brains from axotomized young and old flies. We identified broad transcriptional changes within the ensheathing glia of young flies, and the loss of transcriptional induction of autophagy-associated genes. We also identify age-dependent loss of transcriptional induction of 18 transcripts encoding for small and large ribosomal protein subunits following injury in old flies, suggesting dysregulation of ribosomal biogenesis contributes to loss of glial function. Together, these findings demonstrate a functional link between sleep loss, aging and Wallerian degeneration.
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Keleş MF, Sapci AOB, Brody C, Palmer I, Mehta A, Ahmadi S, Le C, Taştan Ö, Keleş S, Wu MN. FlyVISTA, an integrated machine learning platform for deep phenotyping of sleep in Drosophila. SCIENCE ADVANCES 2025; 11:eadq8131. [PMID: 40073129 PMCID: PMC11900856 DOI: 10.1126/sciadv.adq8131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Accepted: 02/03/2025] [Indexed: 03/14/2025]
Abstract
There is great interest in using genetically tractable organisms such as Drosophila to gain insights into the regulation and function of sleep. However, sleep phenotyping in Drosophila has largely relied on simple measures of locomotor inactivity. Here, we present FlyVISTA, a machine learning platform to perform deep phenotyping of sleep in flies. This platform comprises a high-resolution closed-loop video imaging system, coupled with a deep learning network to annotate 35 body parts, and a computational pipeline to extract behaviors from high-dimensional data. FlyVISTA reveals the distinct spatiotemporal dynamics of sleep and wake-associated microbehaviors at baseline, following administration of the sleep-inducing drug gaboxadol, and with dorsal fan-shaped body drivers. We identify a microbehavior ("haltere switch") exclusively seen during quiescence that indicates a deeper sleep stage. These results enable the rigorous analysis of sleep in Drosophila and set the stage for computational analyses of microbehaviors in quiescent animals.
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Affiliation(s)
- Mehmet F. Keleş
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Ali Osman Berk Sapci
- Department of Computer Science, Sabanci University, Tuzla, Istanbul 34956, Turkey
| | - Casey Brody
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Isabelle Palmer
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Anuradha Mehta
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Shahin Ahmadi
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Christin Le
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Öznur Taştan
- Department of Computer Science, Sabanci University, Tuzla, Istanbul 34956, Turkey
| | - Sündüz Keleş
- Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Mark N. Wu
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
- Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21287, USA
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Han C, Zhang Z, Lin Y, Huang S, Mao J, Xiang W, Wang F, Liang Y, Chen W, Zhao X. Monitoring Sleep Quality Through Low α-Band Activity in the Prefrontal Cortex Using a Portable Electroencephalogram Device: Longitudinal Study. J Med Internet Res 2025; 27:e67188. [PMID: 40063935 PMCID: PMC11933759 DOI: 10.2196/67188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2024] [Revised: 12/20/2024] [Accepted: 02/04/2025] [Indexed: 03/28/2025] Open
Abstract
BACKGROUND The pursuit of sleep quality has become an important aspect of people's global quest for overall health. However, the objective neurobiological features corresponding to subjective perceptions of sleep quality remain poorly understood. Although previous studies have investigated the relationship between electroencephalogram (EEG) and sleep, the lack of longitudinal follow-up studies raises doubts about the reproducibility of their findings. OBJECTIVE Currently, there is a gap in research regarding the stable associations between EEG data and sleep quality assessed through multiple data collection sessions, which could help identify potential neurobiological targets related to sleep quality. METHODS In this study, we used a portable EEG device to collect resting-state prefrontal cortex EEG data over a 3-month follow-up period from 42 participants (27 in the first month, 25 in the second month, and 40 in the third month). Each month, participants' sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) to estimate their recent sleep quality. RESULTS We found that there is a significant and consistent positive correlation between low α band activity in the prefrontal cortex and PSQI scores (r=0.45, P<.001). More importantly, this correlation remained consistent across all 3-month follow-up recordings (P<.05), regardless of whether we considered the same cohort or expanded the sample size. Furthermore, we discovered that the periodic component of the low α band primarily contributed to this significant association with PSQI. CONCLUSIONS These findings represent the first identification of a stable and reliable neurobiological target related to sleep quality through multiple follow-up sessions. Our results provide a solid foundation for future applications of portable EEG devices in monitoring sleep quality and screening for sleep disorders in a broad population.
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Affiliation(s)
- Chuanliang Han
- School of Biomedical Sciences and Gerald Choa Neuroscience Institute, The Chinese University of Hong Kong, Hong Kong, China (Hong Kong)
| | - Zhizhen Zhang
- Department of Mathematics and Statistics, University of Massachusetts at Amherst, Amherst, MA, United States
| | - Yuchen Lin
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Shaojia Huang
- Shenzhen Shuimu AI Technology Co., Ltd, Shenzhen, China
| | - Jidong Mao
- Shenzhen Shuimu AI Technology Co., Ltd, Shenzhen, China
| | - Weiwen Xiang
- Shenzhen Shuimu AI Technology Co., Ltd, Shenzhen, China
| | - Fang Wang
- Shenzhen Shuimu AI Technology Co., Ltd, Shenzhen, China
| | - Yuping Liang
- Shenzhen Shuimu AI Technology Co., Ltd, Shenzhen, China
| | - Wufang Chen
- Shenzhen Shuimu AI Technology Co., Ltd, Shenzhen, China
| | - Xixi Zhao
- National Clinical Research Center for Mental Disorders & National Center for Mental Disorders, Beijing Key Laboratory of Mental Disorders, Beijing Anding Hospital, Capital Medical University, Beijing, China
- Advanced Innovation Center for Human Brain Protection and Laboratory for Clinical Medicine,, Capital Medical University, Beijing, China
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Jones JD, Holder BL, Montgomery AC, McAdams CV, He E, Burns AE, Eiken KR, Vogt A, Velarde AI, Elder AJ, McEllin JA, Dissel S. The dorsal fan-shaped body is a neurochemically heterogeneous sleep-regulating center in Drosophila. PLoS Biol 2025; 23:e3003014. [PMID: 40138668 DOI: 10.1371/journal.pbio.3003014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 04/03/2025] [Accepted: 01/13/2025] [Indexed: 03/29/2025] Open
Abstract
Sleep is a behavior that is conserved throughout the animal kingdom. Yet, despite extensive studies in humans and animal models, the exact function or functions of sleep remain(s) unknown. A complicating factor in trying to elucidate the function of sleep is the complexity and multiplicity of neuronal circuits that are involved in sleep regulation. It is conceivable that distinct sleep-regulating circuits are only involved in specific aspects of sleep and may underlie different sleep functions. Thus, it would be beneficial to assess the contribution of individual circuits in sleep's putative functions. The intricacy of the mammalian brain makes this task extremely difficult. However, the fruit fly Drosophila melanogaster, with its simpler brain organization, available connectomics, and unparalleled genetics, offers the opportunity to interrogate individual sleep-regulating centers. In Drosophila, neurons projecting to the dorsal fan-shaped body (dFB) have been proposed to be key regulators of sleep, particularly sleep homeostasis. We recently demonstrated that the most widely used genetic tool to manipulate dFB neurons, the 23E10-GAL4 driver, expresses in 2 sleep-regulating neurons (VNC-SP neurons) located in the ventral nerve cord (VNC), the fly analog of the vertebrate spinal cord. Since most data supporting a role for the dFB in sleep regulation have been obtained using 23E10-GAL4, it is unclear whether the sleep phenotypes reported in these studies are caused by dFB neurons or VNC-SP cells. A recent publication replicated our finding that 23E10-GAL4 contains sleep-promoting neurons in the VNC. However, it also proposed that the dFB is not involved in sleep regulation at all, but this suggestion was made using genetic tools that are not dFB-specific and a very mild sleep deprivation protocol. In this study, using a newly created dFB-specific genetic driver line, we demonstrate that optogenetic activation of the majority of 23E10-GAL4 dFB neurons promotes sleep and that these neurons are involved in sleep homeostasis. We also show that dFB neurons require stronger stimulation than VNC-SP cells to promote sleep. In addition, we demonstrate that dFB-induced sleep can consolidate short-term memory (STM) into long-term memory (LTM), suggesting that the benefit of sleep on memory is not circuit-specific. Finally, we show that dFB neurons are neurochemically heterogeneous and can be divided in 3 populations. Most dFB neurons express both glutamate and acetylcholine, while a minority of cells expresses only one of these 2 neurotransmitters. Importantly, dFB neurons do not express GABA, as previously suggested. Using neurotransmitter-specific dFB tools, our data also points at cholinergic dFB neurons as particularly potent at regulating sleep and sleep homeostasis.
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Affiliation(s)
- Joseph D Jones
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - Brandon L Holder
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - Andrew C Montgomery
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - Chloe V McAdams
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - Emily He
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - Anna E Burns
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - Kiran R Eiken
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - Alex Vogt
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - Adriana I Velarde
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - Alexandra J Elder
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - Jennifer A McEllin
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - Stephane Dissel
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
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Juusola M, Takalo J, Kemppainen J, Haghighi KR, Scales B, McManus J, Bridges A, MaBouDi H, Chittka L. Theory of morphodynamic information processing: Linking sensing to behaviour. Vision Res 2025; 227:108537. [PMID: 39755072 DOI: 10.1016/j.visres.2024.108537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 11/27/2024] [Accepted: 12/10/2024] [Indexed: 01/06/2025]
Abstract
The traditional understanding of brain function has predominantly focused on chemical and electrical processes. However, new research in fruit fly (Drosophila) binocular vision reveals ultrafast photomechanical photoreceptor movements significantly enhance information processing, thereby impacting a fly's perception of its environment and behaviour. The coding advantages resulting from these mechanical processes suggest that similar physical motion-based coding strategies may affect neural communication ubiquitously. The theory of neural morphodynamics proposes that rapid biomechanical movements and microstructural changes at the level of neurons and synapses enhance the speed and efficiency of sensory information processing, intrinsic thoughts, and actions by regulating neural information in a phasic manner. We propose that morphodynamic information processing evolved to drive predictive coding, synchronising cognitive processes across neural networks to match the behavioural demands at hand effectively.
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Affiliation(s)
- Mikko Juusola
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK.
| | - Jouni Takalo
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK
| | - Joni Kemppainen
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK
| | | | - Ben Scales
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK
| | - James McManus
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK
| | - Alice Bridges
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK
| | - HaDi MaBouDi
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK
| | - Lars Chittka
- Centre for Brain and Behaviour, School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, UK
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Dai X, Le JQ, Ma D, Rosbash M. Four SpsP neurons are an integrating sleep regulation hub in Drosophila. SCIENCE ADVANCES 2024; 10:eads0652. [PMID: 39576867 PMCID: PMC11584021 DOI: 10.1126/sciadv.ads0652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2024] [Accepted: 10/23/2024] [Indexed: 11/24/2024]
Abstract
Sleep is essential and highly conserved, yet its regulatory mechanisms remain largely unknown. To identify sleep drive neurons, we imaged Drosophila brains with calcium-modulated photoactivatable ratiometric integrator (CaMPARI). The results indicate that the activity of the protocerebral bridge (PB) correlates with sleep drive. We further identified a key three-layer PB circuit, EPG-SpsP-PEcG, in which the four SpsP neurons in the PB respond to ellipsoid body (EB) signals from EPG neurons and send signals back to the EB through PEcG neurons. This circuit is strengthened by sleep deprivation, indicating a plasticity response to sleep drive. SpsP neurons also receive inputs from the sensorimotor brain region, suggesting that they may encode sleep drive by integrating sensorimotor and navigation cues. Together, our experiments show that the four SpsP neurons and their sleep regulatory circuit play an important and dynamic role in sleep regulation.
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Affiliation(s)
- Xihuimin Dai
- Howard Hughes Medical Institute, Brandeis University, Waltham MA 02454, USA
| | - Jasmine Quynh Le
- Howard Hughes Medical Institute, Brandeis University, Waltham MA 02454, USA
| | - Dingbang Ma
- Howard Hughes Medical Institute, Brandeis University, Waltham MA 02454, USA
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, China
| | - Michael Rosbash
- Howard Hughes Medical Institute, Brandeis University, Waltham MA 02454, USA
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Sitaraman D, Vecsey CG, Koochagian C. Activity Monitoring for Analysis of Sleep in Drosophila melanogaster. Cold Spring Harb Protoc 2024; 2024:pdb.top108095. [PMID: 38336390 PMCID: PMC11827337 DOI: 10.1101/pdb.top108095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2024]
Abstract
Sleep is important for survival, and the need for sleep is conserved across species. In the past two decades, the fruit fly Drosophila melanogaster has emerged as a promising system in which to study the genetic, neural, and physiological bases of sleep. Through significant advances in our understanding of the regulation of sleep in flies, the field is poised to address several open questions about sleep, such as how the need for sleep is encoded, how molecular regulators of sleep are situated within brain networks, and what the functions of sleep are. Here, we describe key findings, open questions, and commonly used methods that have been used to inform existing theories and develop new ways of thinking about the function, regulation, and adaptability of sleep behavior.
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Affiliation(s)
- Divya Sitaraman
- Department of Psychology, College of Science, California State University, Hayward, California 94542, USA
| | | | - Casey Koochagian
- Neuroscience Program, Skidmore College, Saratoga Springs, New York 12866, USA
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8
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Van De Poll M, van Swinderen B. Whole-Brain Electrophysiology in Drosophila during Sleep and Wake. Cold Spring Harb Protoc 2024; 2024:pdb.prot108418. [PMID: 38148166 DOI: 10.1101/pdb.prot108418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2023]
Abstract
Sleep studies in Drosophila melanogaster rely mostly on behavioral read-outs to support molecular or circuit-level investigations in this model. Electrophysiology can provide an additional level of understanding in these studies to, for example, investigate changes in brain activity associated with sleep manipulations. In this protocol, we describe a procedure for performing multichannel local field potential (LFP) recordings in the fruit fly, with a flexible system that can be adapted to different experimental paradigms and situations. The approach uses electrodes containing multiple recording sites (16), allowing the acquisition of large amounts of neuronal activity data from a transect through the brain while flies are still able to sleep. The approach starts by tethering the fly, followed by positioning it on an air-supported ball. A multichannel silicon probe is then inserted laterally into the fly brain via one eye, allowing for recording of electrical signals from the retina through to the central brain. These recordings can be acquired under spontaneous conditions or in the presence of visual stimuli, and the minimal surgery promotes long-term recordings (e.g., overnight). Sleep and wake can be tracked using infrared cameras, which allow for the measurement of locomotive activity as well as microbehaviors such as proboscis extensions during sleep. The protocol has been optimized to promote subject survivability, which is an important factor when performing long-term (∼16-h) recordings. The approach described here uses specific recording probes, data acquisition devices, and analysis tools. Although it is expected that some of these items might need to be adapted to the equipment available in different laboratories, the overall aim is to provide an overview on how to record electrical activity across the brain of behaving (and sleeping) flies using this kind of approach and technology.
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Affiliation(s)
- Matthew Van De Poll
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Bruno van Swinderen
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
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9
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Van De Poll M, Tainton-Heap L, Troup M, van Swinderen B. Whole-Brain Electrophysiology and Calcium Imaging in Drosophila during Sleep and Wake. Cold Spring Harb Protoc 2024; 2024:pdb.top108394. [PMID: 38148172 DOI: 10.1101/pdb.top108394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2023]
Abstract
Sleep is likely a whole-brain phenomenon, with most of the brain probably benefiting from this state of decreased arousal. Recent advances in our understanding of some potential sleep functions, such as metabolite clearance and synaptic homeostasis, make it evident why the whole brain is likely impacted by sleep: All neurons have synapses, and all neurons produce waste metabolites. Sleep experiments in the fly Drosophila melanogaster suggest that diverse sleep functions appear to be conserved across all animals. Studies of brain activity during sleep in humans typically involve multidimensional data sets, such as those acquired by electroencephalograms (EEGs) or functional magnetic resonance imaging (fMRI), and these whole-brain read-outs often reveal important qualities of different sleep stages, such as changes in frequency dynamics or connectivity. Recently, various techniques have been developed that allow for the recording of neural activity simultaneously across multiple regions of the fly brain. These whole-brain-recording approaches will be important for better understanding sleep physiology and function, as they provide a more comprehensive view of neural dynamics during sleep and wake in a relevant model system. Here, we present a brief summary of some of the findings derived from sleep activity recording studies in sleeping Drosophila flies and discuss the value of electrophysiological versus calcium imaging techniques. Although these involve very different preparations, they both highlight the value of multidimensional data for studying sleep in this model system, like the use of both EEG and fMRI in humans.
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Affiliation(s)
- Matthew Van De Poll
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Lucy Tainton-Heap
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Michael Troup
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Bruno van Swinderen
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
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10
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Tainton-Heap L, Troup M, Van De Poll M, van Swinderen B. Whole-Brain Calcium Imaging in Drosophila during Sleep and Wake. Cold Spring Harb Protoc 2024; 2024:pdb.prot108419. [PMID: 38148168 DOI: 10.1101/pdb.prot108419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2023]
Abstract
Genetically encoded calcium indicators (GECIs) allow for the noninvasive evaluation of neuronal activity in vivo, and imaging GECIs in Drosophila has become commonplace for understanding neural functions and connectivity in this system. GECIs can also be used as read-outs for studying sleep in this model organism. Here, we describe a methodology for tracking the activity of neurons in the fly brain using a two-photon (2p) microscopy system. This method can be adapted to perform functional studies of neural activity in Drosophila under both spontaneous and evoked conditions, as well as during spontaneous or induced sleep. We first describe a tethering and surgical procedure that allows survival under the microscopy conditions required for long-term recordings. We then outline the steps and reagents required for optogenetic activation of sleep-promoting neurons while simultaneously recording neural activity from the fly brain. We also describe the procedure for recording from two different locations-namely, the top of the head (e.g., to record mushroom body calyx activity) or the back of the head (e.g., to record central complex activity). We also provide different strategies for recording from GECIs confined to the cell body versus the entire neuron. Finally, we describe the steps required for analyzing the multidimensional data that can be acquired. In all, this protocol shows how to perform calcium imaging experiments in tethered flies, with a focus on acquiring spontaneous and induced sleep data.
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Affiliation(s)
- Lucy Tainton-Heap
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Michael Troup
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Matthew Van De Poll
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Bruno van Swinderen
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
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11
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Keleş MF, Sapci AOB, Brody C, Palmer I, Le C, Taştan Ö, Keleş S, Wu MN. FlyVISTA, an Integrated Machine Learning Platform for Deep Phenotyping of Sleep in Drosophila. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.30.564733. [PMID: 37961473 PMCID: PMC10635029 DOI: 10.1101/2023.10.30.564733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Animal behavior depends on internal state. While subtle movements can signify significant changes in internal state, computational methods for analyzing these "microbehaviors" are lacking. Here, we present FlyVISTA, a machine-learning platform to characterize microbehaviors in freely-moving flies, which we use to perform deep phenotyping of sleep. This platform comprises a high-resolution closed-loop video imaging system, coupled with a deep-learning network to annotate 35 body parts, and a computational pipeline to extract behaviors from high-dimensional data. FlyVISTA reveals the distinct spatiotemporal dynamics of sleep-associated microbehaviors in flies. We further show that stimulation of dorsal fan-shaped body neurons induces micromovements, not sleep, whereas activating R5 ring neurons triggers rhythmic proboscis extension followed by persistent sleep. Importantly, we identify a novel microbehavior ("haltere switch") exclusively seen during quiescence that indicates a deeper sleep stage. These findings enable the rigorous analysis of sleep in Drosophila and set the stage for computational analyses of microbehaviors.
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Affiliation(s)
- Mehmet F. Keleş
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Ali Osman Berk Sapci
- Department of Computer Science, Sabanci University, Tuzla, Istanbul, 34956, Turkey
| | - Casey Brody
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Isabelle Palmer
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Christin Le
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Öznur Taştan
- Department of Computer Science, Sabanci University, Tuzla, Istanbul, 34956, Turkey
| | - Sündüz Keleş
- Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Mark N. Wu
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
- Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21287, USA
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12
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Omond SET, Lesku JA. Why study sleep in flatworms? J Comp Physiol B 2024; 194:233-239. [PMID: 36899149 PMCID: PMC11233290 DOI: 10.1007/s00360-023-01480-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 01/31/2023] [Accepted: 02/23/2023] [Indexed: 03/12/2023]
Abstract
The behaviors that characterize sleep have been observed across a broad range of different species. While much attention has been placed on vertebrates (mostly mammals and birds), the grand diversity of invertebrates has gone largely unexplored. Here, we introduce the intrigue and special value in the study of sleeping platyhelminth flatworms. Flatworms are closely related to annelids and mollusks, and yet are comparatively simple. They lack a circulatory system, respiratory system, endocrine glands, a coelom, and an anus. They retain a central and peripheral nervous system, various sensory systems, and an ability to learn. Flatworms sleep, like other animals, a state which is regulated by prior sleep/wake history and by the neurotransmitter GABA. Furthermore, they possess a remarkable ability to regenerate from a mere fragment of the original animal. The regenerative capabilities of flatworms make them a unique bilaterally symmetric animal to study a link between sleep and neurodevelopment. Lastly, the recent applications of tools for probing the flatworm genome, metabolism, and brain activity make their entrance into the field of sleep research all the more timely.
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Affiliation(s)
- Shauni E T Omond
- School of Agriculture, Biomedicine & Environment, La Trobe University, Melbourne, Australia.
| | - John A Lesku
- School of Agriculture, Biomedicine & Environment, La Trobe University, Melbourne, Australia.
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13
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Suárez-Grimalt R, Grunwald Kadow IC, Scheunemann L. An integrative sensor of body states: how the mushroom body modulates behavior depending on physiological context. Learn Mem 2024; 31:a053918. [PMID: 38876486 PMCID: PMC11199956 DOI: 10.1101/lm.053918.124] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 04/08/2024] [Indexed: 06/16/2024]
Abstract
The brain constantly compares past and present experiences to predict the future, thereby enabling instantaneous and future behavioral adjustments. Integration of external information with the animal's current internal needs and behavioral state represents a key challenge of the nervous system. Recent advancements in dissecting the function of the Drosophila mushroom body (MB) at the single-cell level have uncovered its three-layered logic and parallel systems conveying positive and negative values during associative learning. This review explores a lesser-known role of the MB in detecting and integrating body states such as hunger, thirst, and sleep, ultimately modulating motivation and sensory-driven decisions based on the physiological state of the fly. State-dependent signals predominantly affect the activity of modulatory MB input neurons (dopaminergic, serotoninergic, and octopaminergic), but also induce plastic changes directly at the level of the MB intrinsic and output neurons. Thus, the MB emerges as a tightly regulated relay station in the insect brain, orchestrating neuroadaptations due to current internal and behavioral states leading to short- but also long-lasting changes in behavior. While these adaptations are crucial to ensure fitness and survival, recent findings also underscore how circuit motifs in the MB may reflect fundamental design principles that contribute to maladaptive behaviors such as addiction or depression-like symptoms.
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Affiliation(s)
- Raquel Suárez-Grimalt
- Institute for Biology/Genetics, Freie Universität Berlin, 14195 Berlin, Germany
- Institut für Neurophysiologie and NeuroCure Cluster of Excellence, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany
| | | | - Lisa Scheunemann
- Institute for Biology/Genetics, Freie Universität Berlin, 14195 Berlin, Germany
- Institut für Neurophysiologie and NeuroCure Cluster of Excellence, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany
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14
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Draper IR, Roberts MA, Gailloud M, Jackson FR. Drosophila noktochor regulates night sleep via a local mushroom body circuit. iScience 2024; 27:109106. [PMID: 38380256 PMCID: PMC10877950 DOI: 10.1016/j.isci.2024.109106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 11/22/2023] [Accepted: 01/31/2024] [Indexed: 02/22/2024] Open
Abstract
We show that a sleep-regulating, Ig-domain protein (NKT) is secreted from Drosophila mushroom body (MB) α'/β' neurons to act locally on other MB cell types. Pan-neuronal or broad MB expression of membrane-tethered NKT (tNkt) protein reduced sleep, like that of an NKT null mutant, suggesting blockade of a receptor mediating endogenous NKT action. In contrast, expression in neurons requiring NKT (the MB α'/β' cells), or non-MB sleep-regulating centers, did not reduce night sleep, indicating the presence of a local MB sleep-regulating circuit consisting of communicating neural subtypes. We suggest that the leucocyte-antigen-related like (Lar) transmembrane receptor may mediate NKT action. Knockdown or overexpression of Lar in the MB increased or decreased sleep, respectively, indicating the receptor promotes wakefulness. Surprisingly, selective expression of tNkt or knockdown of Lar in MB wake-promoting cells increased rather than decreased sleep, suggesting that NKT acts on wake- as well as sleep-promoting cell types to regulate sleep.
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Affiliation(s)
- Isabelle R Draper
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
- Department of Medicine, Molecular Cardiology Research Institute, Tufts Medical Center, 800 Washington Street, Boston, MA 02111, USA
| | - Mary A Roberts
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Matthew Gailloud
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - F Rob Jackson
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
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15
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Jiang-Xie LF, Drieu A, Bhasiin K, Quintero D, Smirnov I, Kipnis J. Neuronal dynamics direct cerebrospinal fluid perfusion and brain clearance. Nature 2024; 627:157-164. [PMID: 38418877 PMCID: PMC12054998 DOI: 10.1038/s41586-024-07108-6] [Citation(s) in RCA: 47] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 01/23/2024] [Indexed: 03/02/2024]
Abstract
The accumulation of metabolic waste is a leading cause of numerous neurological disorders, yet we still have only limited knowledge of how the brain performs self-cleansing. Here we demonstrate that neural networks synchronize individual action potentials to create large-amplitude, rhythmic and self-perpetuating ionic waves in the interstitial fluid of the brain. These waves are a plausible mechanism to explain the correlated potentiation of the glymphatic flow1,2 through the brain parenchyma. Chemogenetic flattening of these high-energy ionic waves largely impeded cerebrospinal fluid infiltration into and clearance of molecules from the brain parenchyma. Notably, synthesized waves generated through transcranial optogenetic stimulation substantially potentiated cerebrospinal fluid-to-interstitial fluid perfusion. Our study demonstrates that neurons serve as master organizers for brain clearance. This fundamental principle introduces a new theoretical framework for the functioning of macroscopic brain waves.
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Affiliation(s)
- Li-Feng Jiang-Xie
- Brain Immunology and Glia (BIG) Center, Washington University in St Louis, St Louis, MO, USA.
- Department of Pathology and Immunology, School of Medicine, Washington University in St Louis, St Louis, MO, USA.
| | - Antoine Drieu
- Brain Immunology and Glia (BIG) Center, Washington University in St Louis, St Louis, MO, USA
- Department of Pathology and Immunology, School of Medicine, Washington University in St Louis, St Louis, MO, USA
| | - Kesshni Bhasiin
- Brain Immunology and Glia (BIG) Center, Washington University in St Louis, St Louis, MO, USA
- Department of Pathology and Immunology, School of Medicine, Washington University in St Louis, St Louis, MO, USA
| | - Daniel Quintero
- Brain Immunology and Glia (BIG) Center, Washington University in St Louis, St Louis, MO, USA
- Department of Pathology and Immunology, School of Medicine, Washington University in St Louis, St Louis, MO, USA
| | - Igor Smirnov
- Brain Immunology and Glia (BIG) Center, Washington University in St Louis, St Louis, MO, USA
- Department of Pathology and Immunology, School of Medicine, Washington University in St Louis, St Louis, MO, USA
| | - Jonathan Kipnis
- Brain Immunology and Glia (BIG) Center, Washington University in St Louis, St Louis, MO, USA.
- Department of Pathology and Immunology, School of Medicine, Washington University in St Louis, St Louis, MO, USA.
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16
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Jagannathan SR, Jeans T, Van De Poll MN, van Swinderen B. Multivariate classification of multichannel long-term electrophysiology data identifies different sleep stages in fruit flies. SCIENCE ADVANCES 2024; 10:eadj4399. [PMID: 38381836 PMCID: PMC10881036 DOI: 10.1126/sciadv.adj4399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 01/18/2024] [Indexed: 02/23/2024]
Abstract
Identifying different sleep stages in humans and other mammals has traditionally relied on electroencephalograms. Such an approach is not feasible in certain animals such as invertebrates, although these animals could also be sleeping in stages. Here, we perform long-term multichannel local field potential recordings in the brains of behaving flies undergoing spontaneous sleep bouts. We acquired consistent spatial recordings of local field potentials across multiple flies, allowing us to compare brain activity across awake and sleep periods. Using machine learning, we uncover distinct temporal stages of sleep and explore the associated spatial and spectral features across the fly brain. Further, we analyze the electrophysiological correlates of microbehaviors associated with certain sleep stages. We confirm the existence of a distinct sleep stage associated with rhythmic proboscis extensions and show that spectral features of this sleep-related behavior differ significantly from those associated with the same behavior during wakefulness, indicating a dissociation between behavior and the brain states wherein these behaviors reside.
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Affiliation(s)
- Sridhar R. Jagannathan
- Department of Psychology, University of Cambridge, Cambridge, UK
- Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Travis Jeans
- Queensland Brain Institute, The University of Queensland, St Lucia, QLD Australia
| | | | - Bruno van Swinderen
- Queensland Brain Institute, The University of Queensland, St Lucia, QLD Australia
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17
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Abhilash L, Shafer OT. A two-process model of Drosophila sleep reveals an inter-dependence between circadian clock speed and the rate of sleep pressure decay. Sleep 2024; 47:zsad277. [PMID: 37930351 PMCID: PMC11275470 DOI: 10.1093/sleep/zsad277] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 10/18/2023] [Indexed: 11/07/2023] Open
Abstract
Sleep is controlled by two processes-a circadian clock that regulates its timing and a homeostat that regulates the drive to sleep. Drosophila has been an insightful model for understanding both processes. For four decades, Borbély and Daan's two-process model has provided a powerful framework for understanding sleep regulation. However, the field of fly sleep has not employed such a model as a framework for the investigation of sleep. To this end, we have adapted the two-process model to the fly and established its utility by showing that it can provide empirically testable predictions regarding the circadian and homeostatic control of fly sleep. We show that the ultradian rhythms previously reported for loss-of-function clock mutants in the fly are robustly detectable and a predictable consequence of a functional sleep homeostat in the absence of a functioning circadian system. We find that a model in which the circadian clock speed and homeostatic rates act without influencing each other provides imprecise predictions regarding how clock speed influences the strength of sleep rhythms and the amount of daily sleep. We also find that quantitatively good fits between empirical values and model predictions were achieved only when clock speeds were positively correlated with rates of decay of sleep pressure. Our results indicate that longer sleep bouts better reflect the homeostatic process than the current definition of sleep as any inactivity lasting 5 minutes or more. This two-process model represents a powerful framework for work on the molecular and physiological regulation of fly sleep.
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Affiliation(s)
- Lakshman Abhilash
- The Advanced Science Research Center, The City University of New York, New York, NY, USA
| | - Orie Thomas Shafer
- The Advanced Science Research Center, The City University of New York, New York, NY, USA
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18
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Anthoney N, Tainton-Heap L, Luong H, Notaras E, Kewin AB, Zhao Q, Perry T, Batterham P, Shaw PJ, van Swinderen B. Experimentally induced active and quiet sleep engage non-overlapping transcriptional programs in Drosophila. eLife 2023; 12:RP88198. [PMID: 37910019 PMCID: PMC10619980 DOI: 10.7554/elife.88198] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023] Open
Abstract
Sleep in mammals can be broadly classified into two different physiological categories: rapid eye movement (REM) sleep and slow-wave sleep (SWS), and accordingly REM and SWS are thought to achieve a different set of functions. The fruit fly Drosophila melanogaster is increasingly being used as a model to understand sleep functions, although it remains unclear if the fly brain also engages in different kinds of sleep as well. Here, we compare two commonly used approaches for studying sleep experimentally in Drosophila: optogenetic activation of sleep-promoting neurons and provision of a sleep-promoting drug, gaboxadol. We find that these different sleep-induction methods have similar effects on increasing sleep duration, but divergent effects on brain activity. Transcriptomic analysis reveals that drug-induced deep sleep ('quiet' sleep) mostly downregulates metabolism genes, whereas optogenetic 'active' sleep upregulates a wide range of genes relevant to normal waking functions. This suggests that optogenetics and pharmacological induction of sleep in Drosophila promote different features of sleep, which engage different sets of genes to achieve their respective functions.
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Affiliation(s)
- Niki Anthoney
- Queensland Brain Institute, The University of QueenslandBrisbaneAustralia
| | - Lucy Tainton-Heap
- Queensland Brain Institute, The University of QueenslandBrisbaneAustralia
| | - Hang Luong
- School of BioSciences, The University of MelbourneMelbourneAustralia
| | - Eleni Notaras
- Queensland Brain Institute, The University of QueenslandBrisbaneAustralia
| | - Amber B Kewin
- Queensland Brain Institute, The University of QueenslandBrisbaneAustralia
| | - Qiongyi Zhao
- Queensland Brain Institute, The University of QueenslandBrisbaneAustralia
| | - Trent Perry
- School of BioSciences, The University of MelbourneMelbourneAustralia
| | - Philip Batterham
- School of BioSciences, The University of MelbourneMelbourneAustralia
| | - Paul J Shaw
- Department of Neuroscience, School of Medicine, Washington University in St. LouisSt LouisUnited States
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19
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Anthoney N, Tainton-Heap LA, Luong H, Notaras E, Kewin AB, Zhao Q, Perry T, Batterham P, Shaw PJ, van Swinderen B. Experimentally induced active and quiet sleep engage non-overlapping transcriptional programs in Drosophila. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.03.535331. [PMID: 37066182 PMCID: PMC10103959 DOI: 10.1101/2023.04.03.535331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Sleep in mammals can be broadly classified into two different physiological categories: rapid eye movement (REM) sleep and slow wave sleep (SWS), and accordingly REM and SWS are thought to achieve a different set of functions. The fruit fly Drosophila melanogaster is increasingly being used as a model to understand sleep functions, although it remains unclear if the fly brain also engages in different kinds of sleep as well. Here, we compare two commonly used approaches for studying sleep experimentally in Drosophila: optogenetic activation of sleep-promoting neurons and provision of a sleep-promoting drug, Gaboxadol. We find that these different sleep-induction methods have similar effects on increasing sleep duration, but divergent effects on brain activity. Transcriptomic analysis reveals that drug-induced deep sleep ('quiet' sleep) mostly downregulates metabolism genes, whereas optogenetic 'active' sleep upregulates a wide range of genes relevant to normal waking functions. This suggests that optogenetics and pharmacological induction of sleep in Drosophila promote different features of sleep, which engage different sets of genes to achieve their respective functions.
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Affiliation(s)
- Niki Anthoney
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072 Australia
| | | | - Hang Luong
- School of BioSciences, The University of Melbourne, Melbourne, VIC 3052 Australia
| | - Eleni Notaras
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072 Australia
| | - Amber B. Kewin
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072 Australia
| | - Qiongyi Zhao
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072 Australia
| | - Trent Perry
- School of BioSciences, The University of Melbourne, Melbourne, VIC 3052 Australia
| | - Philip Batterham
- School of BioSciences, The University of Melbourne, Melbourne, VIC 3052 Australia
| | - Paul J. Shaw
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO USA
| | - Bruno van Swinderen
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072 Australia
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20
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Roland PE. How far neuroscience is from understanding brains. Front Syst Neurosci 2023; 17:1147896. [PMID: 37867627 PMCID: PMC10585277 DOI: 10.3389/fnsys.2023.1147896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 07/31/2023] [Indexed: 10/24/2023] Open
Abstract
The cellular biology of brains is relatively well-understood, but neuroscientists have not yet generated a theory explaining how brains work. Explanations of how neurons collectively operate to produce what brains can do are tentative and incomplete. Without prior assumptions about the brain mechanisms, I attempt here to identify major obstacles to progress in neuroscientific understanding of brains and central nervous systems. Most of the obstacles to our understanding are conceptual. Neuroscience lacks concepts and models rooted in experimental results explaining how neurons interact at all scales. The cerebral cortex is thought to control awake activities, which contrasts with recent experimental results. There is ambiguity distinguishing task-related brain activities from spontaneous activities and organized intrinsic activities. Brains are regarded as driven by external and internal stimuli in contrast to their considerable autonomy. Experimental results are explained by sensory inputs, behavior, and psychological concepts. Time and space are regarded as mutually independent variables for spiking, post-synaptic events, and other measured variables, in contrast to experimental results. Dynamical systems theory and models describing evolution of variables with time as the independent variable are insufficient to account for central nervous system activities. Spatial dynamics may be a practical solution. The general hypothesis that measurements of changes in fundamental brain variables, action potentials, transmitter releases, post-synaptic transmembrane currents, etc., propagating in central nervous systems reveal how they work, carries no additional assumptions. Combinations of current techniques could reveal many aspects of spatial dynamics of spiking, post-synaptic processing, and plasticity in insects and rodents to start with. But problems defining baseline and reference conditions hinder interpretations of the results. Furthermore, the facts that pooling and averaging of data destroy their underlying dynamics imply that single-trial designs and statistics are necessary.
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Affiliation(s)
- Per E. Roland
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
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21
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Cuddapah VA, Hsu CT, Li Y, Shah HM, Saul C, Killiany S, Shon J, Yue Z, Gionet G, Putt ME, Sehgal A. Sleepiness, not total sleep amount, increases seizure risk. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.30.560325. [PMID: 37873373 PMCID: PMC10592838 DOI: 10.1101/2023.09.30.560325] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Sleep loss has been associated with increased seizure risk since antiquity. Despite this observation standing the test of time, how poor sleep drives susceptibility to seizures remains unclear. To identify underlying mechanisms, we restricted sleep in Drosophila epilepsy models and developed a method to identify spontaneous seizures using quantitative video tracking. Here we find that sleep loss exacerbates seizures but only when flies experience increased sleep need, or sleepiness , and not necessarily with reduced sleep quantity. This is supported by the paradoxical finding that acute activation of sleep-promoting circuits worsens seizures, because it increases sleep need without changing sleep amount. Sleep-promoting circuits become hyperactive after sleep loss and are associated with increased whole-brain activity. During sleep restriction, optogenetic inhibition of sleep-promoting circuits to reduce sleepiness protects against seizures. Downregulation of the 5HT1A serotonin receptor in sleep-promoting cells mediates the effect of sleep need on seizures, and we identify an FDA-approved 5HT1A agonist to mitigate seizures. Our findings demonstrate that while homeostatic sleep is needed to recoup lost sleep, it comes at the cost of increasing seizure susceptibility. We provide an unexpected perspective on interactions between sleep and seizures, and surprisingly implicate sleep- promoting circuits as a therapeutic target for seizure control.
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22
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Li H, Aboudhiaf S, Parrot S, Scote-Blachon C, Benetollo C, Lin JS, Seugnet L. Pallidin function in Drosophila surface glia regulates sleep and is dependent on amino acid availability. Cell Rep 2023; 42:113025. [PMID: 37682712 DOI: 10.1016/j.celrep.2023.113025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 06/16/2023] [Accepted: 08/09/2023] [Indexed: 09/10/2023] Open
Abstract
The Pallidin protein is a central subunit of a multimeric complex called biogenesis of lysosome-related organelles complex 1 (BLOC1) that regulates specific endosomal functions and has been linked to schizophrenia. We show here that downregulation of Pallidin and other members of BLOC1 in the surface glia, the Drosophila equivalent of the blood-brain barrier, reduces and delays nighttime sleep in a circadian-clock-dependent manner. In agreement with BLOC1 involvement in amino acid transport, downregulation of the large neutral amino acid transporter 1 (LAT1)-like transporters JhI-21 and mnd, as well as of TOR (target of rapamycin) amino acid signaling, phenocopy Pallidin knockdown. Furthermore, supplementing food with leucine normalizes the sleep/wake phenotypes of Pallidin downregulation, and we identify a role for Pallidin in the subcellular trafficking of JhI-21. Finally, we provide evidence that Pallidin in surface glia is required for GABAergic neuronal activity. These data identify a BLOC1 function linking essential amino acid availability and GABAergic sleep/wake regulation.
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Affiliation(s)
- Hui Li
- Centre de Recherche en Neurosciences de Lyon, Team WAKING, Université Claude Bernard Lyon 1, INSERM U1028, CNRS UMR 5292, 69675 Bron, France
| | - Sami Aboudhiaf
- Centre de Recherche en Neurosciences de Lyon, Team WAKING, Université Claude Bernard Lyon 1, INSERM U1028, CNRS UMR 5292, 69675 Bron, France
| | - Sandrine Parrot
- Centre de Recherche en Neurosciences de Lyon, NeuroDialyTics Facility, Université Claude Bernard Lyon 1, INSERM U1028, CNRS UMR 5292, 69675 Bron, France
| | - Céline Scote-Blachon
- Centre de Recherche en Neurosciences de Lyon, GenCyTi Facility, Université Claude Bernard Lyon 1, INSERM U1028, CNRS UMR 5292, 69675 Bron, France
| | - Claire Benetollo
- Centre de Recherche en Neurosciences de Lyon, GenCyTi Facility, Université Claude Bernard Lyon 1, INSERM U1028, CNRS UMR 5292, 69675 Bron, France
| | - Jian-Sheng Lin
- Centre de Recherche en Neurosciences de Lyon, Team WAKING, Université Claude Bernard Lyon 1, INSERM U1028, CNRS UMR 5292, 69675 Bron, France
| | - Laurent Seugnet
- Centre de Recherche en Neurosciences de Lyon, Team WAKING, Université Claude Bernard Lyon 1, INSERM U1028, CNRS UMR 5292, 69675 Bron, France.
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23
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De J, Wu M, Lambatan V, Hua Y, Joiner WJ. Re-examining the role of the dorsal fan-shaped body in promoting sleep in Drosophila. Curr Biol 2023; 33:3660-3668.e4. [PMID: 37552985 PMCID: PMC10573663 DOI: 10.1016/j.cub.2023.07.043] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 06/10/2023] [Accepted: 07/20/2023] [Indexed: 08/10/2023]
Abstract
The needs fulfilled by sleep are unknown, though the effects of insufficient sleep are manifold. To better understand how the need to sleep is sensed and discharged, much effort has gone into identifying the neural circuits involved in regulating arousal, especially those that promote sleep. In prevailing models, the dorsal fan-shaped body (dFB) plays a central role in this process in the fly brain. In the present study we manipulated various properties of the dFB including its electrical activity, synaptic output, and endogenous gene expression. In each of these experimental contexts we were unable to identify any effect on sleep that could be unambiguously mapped to the dFB. Furthermore, we found evidence that sleep phenotypes previously attributed to the dFB were caused by genetic manipulations that inadvertently targeted the ventral nerve cord. We also examined expression of two genes whose purported effects have been attributed to functions within a specific subpopulation of dFB neurons. In both cases we found little to no expression in the expected cells. Collectively, our results cast doubt on the prevailing hypothesis that the dFB plays a central role in promoting sleep.
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Affiliation(s)
- Joydeep De
- Department of Pharmacology, 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
| | - Vanessa Lambatan
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yue Hua
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - William J Joiner
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA; Center for Circadian Biology, University of California, San Diego, La Jolla, CA 92093, USA.
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24
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Duhart JM, Buchler JR, Inami S, Kennedy KJ, Jenny BP, Afonso DJS, Koh K. Modulation and neural correlates of postmating sleep plasticity in Drosophila females. Curr Biol 2023; 33:2702-2716.e3. [PMID: 37352854 PMCID: PMC10527417 DOI: 10.1016/j.cub.2023.05.054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 05/09/2023] [Accepted: 05/24/2023] [Indexed: 06/25/2023]
Abstract
Sleep is essential, but animals may forgo sleep to engage in other critical behaviors, such as feeding and reproduction. Previous studies have shown that female flies exhibit decreased sleep after mating, but our understanding of the process is limited. Here, we report that postmating nighttime sleep loss is modulated by diet and sleep deprivation, demonstrating a complex interaction among sleep, reproduction, and diet. We also find that female-specific pC1 neurons and sleep-promoting dorsal fan-shaped body (dFB) neurons are required for postmating sleep plasticity. Activating pC1 neurons leads to sleep suppression on standard fly culture media but has little sleep effect on sucrose-only food. Published connectome data suggest indirect, inhibitory connections among pC1 subtypes. Using calcium imaging, we show that activating the pC1e subtype inhibits dFB neurons. We propose that pC1 and dFB neurons integrate the mating status, food context, and sleep drive to modulate postmating sleep plasticity.
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Affiliation(s)
- José M Duhart
- Department of Neuroscience, the Farber Institute for Neurosciences, and Synaptic Biology Center, Thomas Jefferson University, Philadelphia, PA 19107, USA; Laboratorio de Genética del Comportamiento, Fundación Instituto Leloir-IIBBA-CONICET, Buenos Aires C1405BWE, Argentina; Universidad Nacional de Quilmes, Quilmes B1876BXD, Argentina.
| | - Joseph R Buchler
- Department of Neuroscience, the Farber Institute for Neurosciences, and Synaptic Biology Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Sho Inami
- Department of Neuroscience, the Farber Institute for Neurosciences, and Synaptic Biology Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Kyle J Kennedy
- Department of Neuroscience, the Farber Institute for Neurosciences, and Synaptic Biology Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - B Peter Jenny
- Department of Neuroscience, the Farber Institute for Neurosciences, and Synaptic Biology Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Dinis J S Afonso
- Department of Neuroscience, the Farber Institute for Neurosciences, and Synaptic Biology Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Kyunghee Koh
- Department of Neuroscience, the Farber Institute for Neurosciences, and Synaptic Biology Center, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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25
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Jagannathan SR, Jeans R, Van De Poll MN, van Swinderen B. Multivariate classification of multichannel long-term electrophysiology data identifies different sleep stages in fruit flies. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.12.544704. [PMID: 37398087 PMCID: PMC10312633 DOI: 10.1101/2023.06.12.544704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Sleep is observed in most animals, which suggests it subserves a fundamental process associated with adaptive biological functions. However, the evidence to directly associate sleep with a specific function is lacking, in part because sleep is not a single process in many animals. In humans and other mammals, different sleep stages have traditionally been identified using electroencephalograms (EEGs), but such an approach is not feasible in different animals such as insects. Here, we perform long-term multichannel local field potential (LFP) recordings in the brains of behaving flies undergoing spontaneous sleep bouts. We developed protocols to allow for consistent spatial recordings of LFPs across multiple flies, allowing us to compare the LFP activity across awake and sleep periods and further compare the same to induced sleep. Using machine learning, we uncover the existence of distinct temporal stages of sleep and explore the associated spatial and spectral features across the fly brain. Further, we analyze the electrophysiological correlates of micro-behaviours associated with certain sleep stages. We confirm the existence of a distinct sleep stage associated with rhythmic proboscis extensions and show that spectral features of this sleep-related behavior differ significantly from those associated with the same behavior during wakefulness, indicating a dissociation between behavior and the brain states wherein these behaviors reside.
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Affiliation(s)
- Sridhar R. Jagannathan
- Department of Psychology, University of Cambridge, Cambridge, United Kingdom
- Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Rhiannon Jeans
- Queensland Brain Institute, The University of Queensland, St Lucia, Australia
| | | | - Bruno van Swinderen
- Queensland Brain Institute, The University of Queensland, St Lucia, Australia
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Troup M, Tainton-Heap LAL, van Swinderen B. Neural Ensemble Fragmentation in the Anesthetized Drosophila Brain. J Neurosci 2023; 43:2537-2551. [PMID: 36868857 PMCID: PMC10082453 DOI: 10.1523/jneurosci.1657-22.2023] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 02/15/2023] [Accepted: 02/22/2023] [Indexed: 03/05/2023] Open
Abstract
General anesthetics cause a profound loss of behavioral responsiveness in all animals. In mammals, general anesthesia is induced in part by the potentiation of endogenous sleep-promoting circuits, although "deep" anesthesia is understood to be more similar to coma (Brown et al., 2011). Surgically relevant concentrations of anesthetics, such as isoflurane and propofol, have been shown to impair neural connectivity across the mammalian brain (Mashour and Hudetz, 2017; Yang et al., 2021), which presents one explanation why animals become largely unresponsive when exposed to these drugs. It remains unclear whether general anesthetics affect brain dynamics similarly in all animal brains, or whether simpler animals, such as insects, even display levels of neural connectivity that could be disrupted by these drugs. Here, we used whole-brain calcium imaging in behaving female Drosophila flies to investigate whether isoflurane anesthesia induction activates sleep-promoting neurons, and then inquired how all other neurons across the fly brain behave under sustained anesthesia. We were able to track the activity of hundreds of neurons simultaneously during waking and anesthetized states, for spontaneous conditions as well as in response to visual and mechanical stimuli. We compared whole-brain dynamics and connectivity under isoflurane exposure to optogenetically induced sleep. Neurons in the Drosophila brain remain active during general anesthesia as well as induced sleep, although flies become behaviorally inert under both treatments. We identified surprisingly dynamic neural correlation patterns in the waking fly brain, suggesting ensemble-like behavior. These become more fragmented and less diverse under anesthesia but remain wake-like during induced sleep.SIGNIFICANCE STATEMENT When humans are rendered immobile and unresponsive by sleep or general anesthetics, their brains do not shut off - they just change how they operate. We tracked the activity of hundreds of neurons simultaneously in the brains of fruit flies that were anesthetized by isoflurane or genetically put to sleep, to investigate whether these behaviorally inert states shared similar brain dynamics. We uncovered dynamic patterns of neural activity in the waking fly brain, with stimulus-responsive neurons constantly changing through time. Wake-like neural dynamics persisted during induced sleep but became more fragmented under isoflurane anesthesia. This suggests that, like larger brains, the fly brain might also display ensemble-like behavior, which becomes degraded rather than silenced under general anesthesia.
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Affiliation(s)
- Michael Troup
- Queensland Brain Institute, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Lucy A L Tainton-Heap
- Queensland Brain Institute, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Bruno van Swinderen
- Queensland Brain Institute, The University of Queensland, St. Lucia, Queensland 4072, Australia
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27
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Zhang Z, Li K, Hu X. Mapping nonlinear brain dynamics by phase space embedding with fMRI data. Biomed Signal Process Control 2023. [DOI: 10.1016/j.bspc.2022.104521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Jones JD, Holder BL, Eiken KR, Vogt A, Velarde AI, Elder AJ, McEllin JA, Dissel S. Regulation of sleep by cholinergic neurons located outside the central brain in Drosophila. PLoS Biol 2023; 21:e3002012. [PMID: 36862736 PMCID: PMC10013921 DOI: 10.1371/journal.pbio.3002012] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 03/14/2023] [Accepted: 01/25/2023] [Indexed: 03/03/2023] Open
Abstract
Sleep is a complex and plastic behavior regulated by multiple brain regions and influenced by numerous internal and external stimuli. Thus, to fully uncover the function(s) of sleep, cellular resolution of sleep-regulating neurons needs to be achieved. Doing so will help to unequivocally assign a role or function to a given neuron or group of neurons in sleep behavior. In the Drosophila brain, neurons projecting to the dorsal fan-shaped body (dFB) have emerged as a key sleep-regulating area. To dissect the contribution of individual dFB neurons to sleep, we undertook an intersectional Split-GAL4 genetic screen focusing on cells contained within the 23E10-GAL4 driver, the most widely used tool to manipulate dFB neurons. In this study, we demonstrate that 23E10-GAL4 expresses in neurons outside the dFB and in the fly equivalent of the spinal cord, the ventral nerve cord (VNC). Furthermore, we show that 2 VNC cholinergic neurons strongly contribute to the sleep-promoting capacity of the 23E10-GAL4 driver under baseline conditions. However, in contrast to other 23E10-GAL4 neurons, silencing these VNC cells does not block sleep homeostasis. Thus, our data demonstrate that the 23E10-GAL4 driver contains at least 2 different types of sleep-regulating neurons controlling distinct aspects of sleep behavior.
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Affiliation(s)
- Joseph D. Jones
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - Brandon L. Holder
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - Kiran R. Eiken
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - Alex Vogt
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - Adriana I. Velarde
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - Alexandra J. Elder
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - Jennifer A. McEllin
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - Stephane Dissel
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
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Rattenborg NC, Ungurean G. The evolution and diversification of sleep. Trends Ecol Evol 2023; 38:156-170. [PMID: 36411158 DOI: 10.1016/j.tree.2022.10.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 10/17/2022] [Accepted: 10/24/2022] [Indexed: 11/19/2022]
Abstract
The evolutionary origins of sleep and its sub-states, rapid eye movement (REM) and non-REM (NREM) sleep, found in mammals and birds, remain a mystery. Although the discovery of a single type of sleep in jellyfish suggests that sleep evolved much earlier than previously thought, it is unclear when and why sleep diversified into multiple types of sleep. Intriguingly, multiple types of sleep have recently been found in animals ranging from non-avian reptiles to arthropods to cephalopods. Although there are similarities between these states and those found in mammals and birds, notable differences also exist. The diversity in the way sleep is expressed confounds attempts to trace the evolution of sleep states, but also serves as a rich resource for exploring the functions of sleep.
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Affiliation(s)
- Niels C Rattenborg
- Max Planck Institute for Biological Intelligence (in foundation), Seewiesen, Germany.
| | - Gianina Ungurean
- Max Planck Institute for Biological Intelligence (in foundation), Seewiesen, Germany
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Huang S, Piao C, Beuschel CB, Zhao Z, Sigrist SJ. A brain-wide form of presynaptic active zone plasticity orchestrates resilience to brain aging in Drosophila. PLoS Biol 2022; 20:e3001730. [PMID: 36469518 PMCID: PMC9721493 DOI: 10.1371/journal.pbio.3001730] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 11/07/2022] [Indexed: 12/10/2022] Open
Abstract
The brain as a central regulator of stress integration determines what is threatening, stores memories, and regulates physiological adaptations across the aging trajectory. While sleep homeostasis seems to be linked to brain resilience, how age-associated changes intersect to adapt brain resilience to life history remains enigmatic. We here provide evidence that a brain-wide form of presynaptic active zone plasticity ("PreScale"), characterized by increases of active zone scaffold proteins and synaptic vesicle release factors, integrates resilience by coupling sleep, longevity, and memory during early aging of Drosophila. PreScale increased over the brain until mid-age, to then decreased again, and promoted the age-typical adaption of sleep patterns as well as extended longevity, while at the same time it reduced the ability of forming new memories. Genetic induction of PreScale also mimicked early aging-associated adaption of sleep patterns and the neuronal activity/excitability of sleep control neurons. Spermidine supplementation, previously shown to suppress early aging-associated PreScale, also attenuated the age-typical sleep pattern changes. Pharmacological induction of sleep for 2 days in mid-age flies also reset PreScale, restored memory formation, and rejuvenated sleep patterns. Our data suggest that early along the aging trajectory, PreScale acts as an acute, brain-wide form of presynaptic plasticity to steer trade-offs between longevity, sleep, and memory formation in a still plastic phase of early brain aging.
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Affiliation(s)
- Sheng Huang
- Institute for Biology/Genetics, Freie Universität Berlin, Berlin, Germany
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin, Berlin, Germany
| | - Chengji Piao
- Institute for Biology/Genetics, Freie Universität Berlin, Berlin, Germany
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin, Berlin, Germany
| | - Christine B. Beuschel
- Institute for Biology/Genetics, Freie Universität Berlin, Berlin, Germany
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin, Berlin, Germany
| | - Zhiying Zhao
- Institute for Biology/Genetics, Freie Universität Berlin, Berlin, Germany
| | - Stephan J. Sigrist
- Institute for Biology/Genetics, Freie Universität Berlin, Berlin, Germany
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin, Berlin, Germany
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31
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Qiu S, Sun K, Di Z. Long-range connections are crucial for synchronization transition in a computational model of Drosophila brain dynamics. Sci Rep 2022; 12:20104. [PMID: 36418353 PMCID: PMC9684149 DOI: 10.1038/s41598-022-17544-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 07/27/2022] [Indexed: 11/24/2022] Open
Abstract
The synchronization transition type has been the focus of attention in recent years because it is associated with many functional characteristics of the brain. In this paper, the synchronization transition in neural networks with sleep-related biological drives in Drosophila is investigated. An electrical synaptic neural network is established to research the difference between the synchronization transition of the network during sleep and wake, in which neurons regularly spike during sleep and chaotically spike during wake. The synchronization transition curves are calculated mainly using the global instantaneous order parameters S. The underlying mechanisms and types of synchronization transition during sleep are different from those during wake. During sleep, regardless of the network structure, a frustrated (discontinuous) transition can be observed. Moreover, the phenomenon of quasi periodic partial synchronization is observed in ring-shaped regular network with and without random long-range connections. As the network becomes dense, the synchronization of the network only needs to slightly increase the coupling strength g. While during wake, the synchronization transition of the neural network is very dependent on the network structure, and three mechanisms of synchronization transition have emerged: discontinuous synchronization (explosive synchronization and frustrated synchronization), and continuous synchronization. The random long-range connections is the main topological factor that plays an important role in the resulting synchronization transition. Furthermore, similarities and differences are found by comparing synchronization transition research for the Hodgkin-Huxley neural network in the beta-band and gammma-band, which can further improve the synchronization phase transition research of biologically motivated neural networks. A complete research framework can also be used to study coupled nervous systems, which can be extended to general coupled dynamic systems.
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Affiliation(s)
- Shuihan Qiu
- grid.20513.350000 0004 1789 9964International Academic Center of Complex Systems, Beijing Normal University, Zhuhai, 519087 China ,grid.20513.350000 0004 1789 9964School of Systems Science, Beijing Normal University, Beijing, 100875 China
| | - Kaijia Sun
- grid.20513.350000 0004 1789 9964School of Systems Science, Beijing Normal University, Beijing, 100875 China
| | - Zengru Di
- grid.20513.350000 0004 1789 9964International Academic Center of Complex Systems, Beijing Normal University, Zhuhai, 519087 China ,grid.20513.350000 0004 1789 9964School of Systems Science, Beijing Normal University, Beijing, 100875 China
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Gong NN, Luong HNB, Dang AH, Mainwaring B, Shields E, Schmeckpeper K, Bonasio R, Kayser MS. Intrinsic maturation of sleep output neurons regulates sleep ontogeny in Drosophila. Curr Biol 2022; 32:4025-4039.e3. [PMID: 35985328 PMCID: PMC9529826 DOI: 10.1016/j.cub.2022.07.054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 06/06/2022] [Accepted: 07/21/2022] [Indexed: 11/19/2022]
Abstract
The maturation of sleep behavior across a lifespan (sleep ontogeny) is an evolutionarily conserved phenomenon. Mammalian studies have shown that in addition to increased sleep duration, early life sleep exhibits stark differences compared with mature sleep with regard to sleep states. How the intrinsic maturation of sleep output circuits contributes to sleep ontogeny is poorly understood. The fruit fly Drosophila melanogaster exhibits multifaceted changes to sleep from juvenile to mature adulthood. Here, we use a non-invasive probabilistic approach to investigate the changes in sleep architecture in juvenile and mature flies. Increased sleep in juvenile flies is driven primarily by a decreased probability of transitioning to wake and characterized by more time in deeper sleep states. Functional manipulations of sleep-promoting neurons in the dorsal fan-shaped body (dFB) suggest that these neurons differentially regulate sleep in juvenile and mature flies. Transcriptomic analysis of dFB neurons at different ages and a subsequent RNAi screen implicate the genes involved in dFB sleep circuit maturation. These results reveal that the dynamic transcriptional states of sleep output neurons contribute to the changes in sleep across the lifespan.
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Affiliation(s)
- Naihua N Gong
- Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hang Ngoc Bao Luong
- Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - An H Dang
- Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Benjamin Mainwaring
- Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Emily Shields
- Department of Urology and Institute of Neuropathology, Medical Center-University of Freiburg, 79106 Freiburg, Germany; Epigenetics Institute and Department of Cell and Developmental Biology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Karl Schmeckpeper
- Department of Computer Science, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Roberto Bonasio
- Epigenetics Institute and Department of Cell and Developmental Biology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Matthew S Kayser
- Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Chronobiology and Sleep Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.
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33
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Omond SET, Hale MW, Lesku JA. Neurotransmitters of sleep and wakefulness in flatworms. Sleep 2022; 45:zsac053. [PMID: 35554581 PMCID: PMC9216492 DOI: 10.1093/sleep/zsac053] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 02/27/2022] [Indexed: 12/02/2022] Open
Abstract
STUDY OBJECTIVES Sleep is a prominent behavioral and biochemical state observed in all animals studied, including platyhelminth flatworms. Investigations into the biochemical mechanisms associated with sleep-and wakefulness-are important for understanding how these states are regulated and how that regulation changed with the evolution of new types of animals. Unfortunately, beyond a handful of vertebrates, such studies on invertebrates are rare. METHODS We investigated the effect of seven neurotransmitters, and one pharmacological compound, that modulate either sleep or wakefulness in mammals, on flatworms (Girardia tigrina). Flatworms were exposed via ingestion and diffusion to four neurotransmitters that promote wakefulness in vertebrates (acetylcholine, dopamine, glutamate, histamine), and three that induce sleep (adenosine, GABA, serotonin) along with the H1 histamine receptor antagonist pyrilamine. Compounds were administered over concentrations spanning three to five orders of magnitude. Flatworms were then transferred to fresh water and video recorded for analysis. RESULTS Dopamine and histamine decreased the time spent inactive and increased distance traveled, consistent with their wake-promoting effect in vertebrates and fruit flies; pyrilamine increased restfulness and GABA showed a nonsignificant trend towards promoting restfulness in a dose-dependent manner, in agreement with their sleep-inducing effect in vertebrates, fruit flies, and Hydra. Similar to Hydra, acetylcholine, glutamate, and serotonin, but also adenosine, had no apparent effect on flatworm behavior. CONCLUSIONS These data demonstrate the potential of neurotransmitters to regulate sleep and wakefulness in flatworms and highlight the conserved action of some neurotransmitters across species.
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Affiliation(s)
- Shauni E T Omond
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Australia
| | - Matthew W Hale
- School of Psychology and Public Health, La Trobe University, Melbourne, Australia
| | - John A Lesku
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Australia
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Weiss JT, Donlea JM. Roles for Sleep in Neural and Behavioral Plasticity: Reviewing Variation in the Consequences of Sleep Loss. Front Behav Neurosci 2022; 15:777799. [PMID: 35126067 PMCID: PMC8810646 DOI: 10.3389/fnbeh.2021.777799] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 12/16/2021] [Indexed: 12/13/2022] Open
Abstract
Sleep is a vital physiological state that has been broadly conserved across the evolution of animal species. While the precise functions of sleep remain poorly understood, a large body of research has examined the negative consequences of sleep loss on neural and behavioral plasticity. While sleep disruption generally results in degraded neural plasticity and cognitive function, the impact of sleep loss can vary widely with age, between individuals, and across physiological contexts. Additionally, several recent studies indicate that sleep loss differentially impacts distinct neuronal populations within memory-encoding circuitry. These findings indicate that the negative consequences of sleep loss are not universally shared, and that identifying conditions that influence the resilience of an organism (or neuron type) to sleep loss might open future opportunities to examine sleep's core functions in the brain. Here, we discuss the functional roles for sleep in adaptive plasticity and review factors that can contribute to individual variations in sleep behavior and responses to sleep loss.
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Affiliation(s)
- Jacqueline T. Weiss
- Department of Neurobiology, David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, CA, United States
- Neuroscience Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA, United States
| | - Jeffrey M. Donlea
- Department of Neurobiology, David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, CA, United States
- *Correspondence: Jeffrey M. Donlea
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35
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Jaggard JB, Wang GX, Mourrain P. Non-REM and REM/paradoxical sleep dynamics across phylogeny. Curr Opin Neurobiol 2021; 71:44-51. [PMID: 34583217 PMCID: PMC8719594 DOI: 10.1016/j.conb.2021.08.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/24/2021] [Accepted: 08/26/2021] [Indexed: 12/14/2022]
Abstract
All animals carefully studied sleep, suggesting that sleep as a behavioral state exists in all animal life. Such evolutionary maintenance of an otherwise vulnerable period of environmental detachment suggests that sleep must be integral in fundamental biological needs. Despite over a century of research, the knowledge of what sleep does at the tissue, cellular or molecular levels remain cursory. Currently, sleep is defined based on behavioral criteria and physiological measures rather than at the cellular or molecular level. Physiologically, sleep has been described as two main states, non-rapid eye moment (NREM) and REM/paradoxical sleep (PS), which are defined in the neocortex by synchronous oscillations and paradoxical wake-like activity, respectively. For decades, these two sleep states were believed to be defining characteristics of only mammalian and avian sleep. Recent work has revealed slow oscillation, silencing, and paradoxical/REM-like activities in reptiles, fish, flies, worms, and cephalopods suggesting that these sleep dynamics and associated physiological states may have emerged early in animal evolution. Here, we discuss these recent developments supporting the conservation of neural dynamics (silencing, oscillation, paradoxical activity) of sleep states across phylogeny.
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Affiliation(s)
- James B Jaggard
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
| | - Gordon X Wang
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA; Wu Tsai Neuroscience Institute, Stanford University, Stanford, CA, USA
| | - Philippe Mourrain
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA; INSERM 1024, Ecole Normale Supérieure, Paris, France.
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Hugin + neurons provide a link between sleep homeostat and circadian clock neurons. Proc Natl Acad Sci U S A 2021; 118:2111183118. [PMID: 34782479 DOI: 10.1073/pnas.2111183118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/13/2021] [Indexed: 11/18/2022] Open
Abstract
Sleep is controlled by homeostatic mechanisms, which drive sleep after wakefulness, and a circadian clock, which confers the 24-h rhythm of sleep. These processes interact with each other to control the timing of sleep in a daily cycle as well as following sleep deprivation. However, the mechanisms by which they interact are poorly understood. We show here that hugin + neurons, previously identified as neurons that function downstream of the clock to regulate rhythms of locomotor activity, are also targets of the sleep homeostat. Sleep deprivation decreases activity of hugin + neurons, likely to suppress circadian-driven activity during recovery sleep, and ablation of hugin + neurons promotes sleep increases generated by activation of the homeostatic sleep locus, the dorsal fan-shaped body (dFB). Also, mutations in peptides produced by the hugin + locus increase recovery sleep following deprivation. Transsynaptic mapping reveals that hugin + neurons feed back onto central clock neurons, which also show decreased activity upon sleep loss, in a Hugin peptide-dependent fashion. We propose that hugin + neurons integrate circadian and sleep signals to modulate circadian circuitry and regulate the timing of sleep.
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37
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Van De Poll MN, van Swinderen B. Balancing Prediction and Surprise: A Role for Active Sleep at the Dawn of Consciousness? Front Syst Neurosci 2021; 15:768762. [PMID: 34803618 PMCID: PMC8602873 DOI: 10.3389/fnsys.2021.768762] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 10/08/2021] [Indexed: 11/14/2022] Open
Abstract
The brain is a prediction machine. Yet the world is never entirely predictable, for any animal. Unexpected events are surprising, and this typically evokes prediction error signatures in mammalian brains. In humans such mismatched expectations are often associated with an emotional response as well, and emotional dysregulation can lead to cognitive disorders such as depression or schizophrenia. Emotional responses are understood to be important for memory consolidation, suggesting that positive or negative 'valence' cues more generally constitute an ancient mechanism designed to potently refine and generalize internal models of the world and thereby minimize prediction errors. On the other hand, abolishing error detection and surprise entirely (as could happen by generalization or habituation) is probably maladaptive, as this might undermine the very mechanism that brains use to become better prediction machines. This paradoxical view of brain function as an ongoing balance between prediction and surprise suggests a compelling approach to study and understand the evolution of consciousness in animals. In particular, this view may provide insight into the function and evolution of 'active' sleep. Here, we propose that active sleep - when animals are behaviorally asleep but their brain seems awake - is widespread beyond mammals and birds, and may have evolved as a mechanism for optimizing predictive processing in motile creatures confronted with constantly changing environments. To explore our hypothesis, we progress from humans to invertebrates, investigating how a potential role for rapid eye movement (REM) sleep in emotional regulation in humans could be re-examined as a conserved sleep function that co-evolved alongside selective attention to maintain an adaptive balance between prediction and surprise. This view of active sleep has some interesting implications for the evolution of subjective awareness and consciousness in animals.
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Affiliation(s)
| | - Bruno van Swinderen
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
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38
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Hulse BK, Haberkern H, Franconville R, Turner-Evans D, Takemura SY, Wolff T, Noorman M, Dreher M, Dan C, Parekh R, Hermundstad AM, Rubin GM, Jayaraman V. A connectome of the Drosophila central complex reveals network motifs suitable for flexible navigation and context-dependent action selection. eLife 2021; 10:e66039. [PMID: 34696823 PMCID: PMC9477501 DOI: 10.7554/elife.66039] [Citation(s) in RCA: 171] [Impact Index Per Article: 42.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 09/07/2021] [Indexed: 11/13/2022] Open
Abstract
Flexible behaviors over long timescales are thought to engage recurrent neural networks in deep brain regions, which are experimentally challenging to study. In insects, recurrent circuit dynamics in a brain region called the central complex (CX) enable directed locomotion, sleep, and context- and experience-dependent spatial navigation. We describe the first complete electron microscopy-based connectome of the Drosophila CX, including all its neurons and circuits at synaptic resolution. We identified new CX neuron types, novel sensory and motor pathways, and network motifs that likely enable the CX to extract the fly's head direction, maintain it with attractor dynamics, and combine it with other sensorimotor information to perform vector-based navigational computations. We also identified numerous pathways that may facilitate the selection of CX-driven behavioral patterns by context and internal state. The CX connectome provides a comprehensive blueprint necessary for a detailed understanding of network dynamics underlying sleep, flexible navigation, and state-dependent action selection.
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Affiliation(s)
- Brad K Hulse
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Hannah Haberkern
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Romain Franconville
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Daniel Turner-Evans
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Shin-ya Takemura
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Tanya Wolff
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Marcella Noorman
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Marisa Dreher
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Chuntao Dan
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Ruchi Parekh
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Ann M Hermundstad
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Gerald M Rubin
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Vivek Jayaraman
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
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Malinowski JE, Scheel D, McCloskey M. Do animals dream? Conscious Cogn 2021; 95:103214. [PMID: 34653784 DOI: 10.1016/j.concog.2021.103214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 07/22/2021] [Accepted: 09/21/2021] [Indexed: 10/20/2022]
Abstract
The understanding of biological functions of sleep has improved recently, including an understanding of the deep evolutionary roots of sleep among animals. However, dreaming as an element of sleep may be particularly difficult to address in non-human animals because in humans dreaming involves a non-wakeful form of awareness typically identified through verbal report. Here, we argue that parallels that exist between the phenomenology, physiology, and sleep behaviors during human dreaming provide an avenue to investigate dreaming in non-human animals. We review three alternative measurements of human dreaming - neural correlates of dreaming, 'replay' of newly-acquired memories, and dream-enacting behaviors - and consider how these may be applied to non-human animal models. We suggest that while animals close in brain structure to humans (such as mammals and birds) may be optimal models for the first two of these measurements, cephalopods, especially octopuses, may be particularly good candidates for the third.
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Affiliation(s)
- J E Malinowski
- School of Psychology, University of East London, Stratford, UK.
| | - D Scheel
- Institute of Culture & Environment, Alaska Pacific University, Anchorage, AK, USA.
| | - M McCloskey
- Institute of Culture & Environment, Alaska Pacific University, Anchorage, AK, USA.
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40
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Huang H, Possidente DR, Vecsey CG. Optogenetic activation of SIFamide (SIFa) neurons induces a complex sleep-promoting effect in the fruit fly Drosophila melanogaster. Physiol Behav 2021; 239:113507. [PMID: 34175361 DOI: 10.1016/j.physbeh.2021.113507] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 05/20/2021] [Accepted: 06/22/2021] [Indexed: 10/21/2022]
Abstract
Sleep is a universal and extremely complicated function. Sleep is regulated by two systems-sleep homeostasis and circadian rhythms. In a wide range of species, neuropeptides have been found to play a crucial role in the communication and synchronization between different components of both systems. In the fruit fly Drosophila melanogaster, SIFamide (SIFa) is a neuropeptide that has been reported to be expressed in 4 neurons in the pars intercerebralis (PI) area of the brain. Previous work has shown that transgenic ablation of SIFa neurons, mutation of SIFa itself, or knockdown of SIFa receptors reduces sleep, suggesting that SIFa is sleep-promoting. However, those were all constitutive manipulations that could have affected development or resulted in compensation, so the role of SIFa signaling in sleep regulation during adulthood remains unclear. In the current study, we examined the sleep-promoting effect of SIFa through an optogenetic approach, which allowed for neuronal activation with high temporal resolution, while leaving development unaffected. We found that activation of the red-light sensor Chrimson in SIFa neurons promoted sleep in flies in a sexually dimorphic manner, where the magnitude of the sleep effect was greater in females than in males. Because neuropeptidergic neurons often also release other transmitters, we used RNA interference to knock down SIFa while also optogenetically activating SIFa neurons. SIFa knockdown only partially reduced the magnitude of the sleep effect, suggesting that release of other transmitters may contribute to the sleep induction when SIFa neurons are activated. Video-based analysis showed that activation of SIFa neurons for as brief a period as 1 second was able to decrease walking behavior for minutes after the stimulus. Future studies should aim to identify the transmitters that are utilized by SIFa neurons and characterize their upstream activators and downstream targets. It would also be of interest to determine how acute optogenetic activation of SIFa neurons alters other behaviors that have been linked to SIFa, such as mating and feeding.
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Affiliation(s)
- Haoyang Huang
- Neuroscience Program, Skidmore College, 815 N. Broadway, Saratoga Springs, NY 12866
| | - Debra R Possidente
- Neuroscience Program, Skidmore College, 815 N. Broadway, Saratoga Springs, NY 12866
| | - Christopher G Vecsey
- Neuroscience Program, Skidmore College, 815 N. Broadway, Saratoga Springs, NY 12866.
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41
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Gutierrez BC, Pita Almenar MR, Martínez LJ, Siñeriz Louis M, Albarracín VH, Cantero MDR, Cantiello HF. Honeybee Brain Oscillations Are Generated by Microtubules. The Concept of a Brain Central Oscillator. Front Mol Neurosci 2021; 14:727025. [PMID: 34658784 PMCID: PMC8511451 DOI: 10.3389/fnmol.2021.727025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 09/06/2021] [Indexed: 12/30/2022] Open
Abstract
Microtubules (MTs) are important structures of the cytoskeleton in neurons. Mammalian brain MTs act as biomolecular transistors that generate highly synchronous electrical oscillations. However, their role in brain function is largely unknown. To gain insight into the MT electrical oscillatory activity of the brain, we turned to the honeybee (Apis mellifera) as a useful model to isolate brains and MTs. The patch clamp technique was applied to MT sheets of purified honeybee brain MTs. High resistance seal patches showed electrical oscillations that linearly depended on the holding potential between ± 200 mV and had an average conductance in the order of ~9 nS. To place these oscillations in the context of the brain, we also explored local field potential (LFP) recordings from the Triton X-permeabilized whole honeybee brain unmasking spontaneous oscillations after but not before tissue permeabilization. Frequency domain spectral analysis of time records indicated at least two major peaks at approximately ~38 Hz and ~93 Hz in both preparations. The present data provide evidence that MT electrical oscillations are a novel signaling mechanism implicated in brain wave activity observed in the insect brain.
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Affiliation(s)
- Brenda C. Gutierrez
- Laboratorio de Canales Iónicos, Instituto Multidisciplinario de Salud, Tecnología y Desarrollo (IMSaTeD, CONICET-UNSE), Santiago del Estero, Argentina
| | - Marcelo R. Pita Almenar
- Laboratorio de Canales Iónicos, Instituto Multidisciplinario de Salud, Tecnología y Desarrollo (IMSaTeD, CONICET-UNSE), Santiago del Estero, Argentina
| | - Luciano J. Martínez
- Centro Integral de Microscopía Electrónica (CIME-CONICET-UNT), Tucumán, Argentina
| | - Manuel Siñeriz Louis
- Centro Integral de Microscopía Electrónica (CIME-CONICET-UNT), Tucumán, Argentina
| | | | - María del Rocío Cantero
- Laboratorio de Canales Iónicos, Instituto Multidisciplinario de Salud, Tecnología y Desarrollo (IMSaTeD, CONICET-UNSE), Santiago del Estero, Argentina
| | - Horacio F. Cantiello
- Laboratorio de Canales Iónicos, Instituto Multidisciplinario de Salud, Tecnología y Desarrollo (IMSaTeD, CONICET-UNSE), Santiago del Estero, Argentina
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42
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Abstract
Hypersynchronous neural activity is a characteristic feature of seizures. Although many Drosophila mutants of epilepsy-related genes display clear behavioral spasms and motor unit hyperexcitability, field potential measurements of aberrant hypersynchronous activity across brain regions during seizures have yet to be described. Here, we report a straightforward method to observe local field potentials (LFPs) from the Drosophila brain to monitor ensemble neural activity during seizures in behaving tethered flies. High frequency stimulation across the brain reliably triggers a stereotypic sequence of electroconvulsive seizure (ECS) spike discharges readily detectable in the dorsal longitudinal muscle (DLM) and coupled with behavioral spasms. During seizure episodes, the LFP signal displayed characteristic large-amplitude oscillations with a stereotypic temporal correlation to DLM flight muscle spiking. ECS-related LFP events were clearly distinct from rest- and flight-associated LFP patterns. We further characterized the LFP activity during different types of seizures originating from genetic and pharmacological manipulations. In the 'bang-sensitive' sodium channel mutant bangsenseless (bss), the LFP pattern was prolonged, and the temporal correlation between LFP oscillations and DLM discharges was altered. Following administration of the pro-convulsant GABAA blocker picrotoxin, we uncovered a qualitatively different LFP activity pattern, which consisted of a slow (1-Hz), repetitive, waveform, closely coupled with DLM bursting and behavioral spasms. Our approach to record brain LFPs presents an initial framework for electrophysiological analysis of the complex brain-wide activity patterns in the large collection of Drosophila excitability mutants.
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Affiliation(s)
- Atulya Iyengar
- Department of Biology, and Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, USA
| | - Chun-Fang Wu
- Department of Biology, and Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, USA
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43
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Dai X, Zhou E, Yang W, Mao R, Zhang W, Rao Y. Molecular resolution of a behavioral paradox: sleep and arousal are regulated by distinct acetylcholine receptors in different neuronal types in Drosophila. Sleep 2021; 44:6119684. [PMID: 33493349 DOI: 10.1093/sleep/zsab017] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 12/21/2020] [Indexed: 02/02/2023] Open
Abstract
Sleep and arousal are both important for animals. The neurotransmitter acetylcholine (ACh) has long been found to promote both sleep and arousal in mammals, an apparent paradox which has also been found to exist in flies, causing much confusion in understanding sleep and arousal. Here, we have systematically studied all 13 ACh receptors (AChRs) in Drosophila to understand mechanisms underlying ACh function in sleep and arousal. We found that exogenous stimuli-induced arousal was decreased in nAChRα3 mutants, whereas sleep was decreased in nAChRα2 and nAChRβ2 mutants. nAChRα3 functions in dopaminergic neurons to promote exogenous stimuli-induced arousal, whereas nAChRα2 and β2 function in octopaminergic neurons to promote sleep. Our studies have revealed that a single transmitter can promote endogenous sleep and exogenous stimuli-induced arousal through distinct receptors in different types of downstream neurons.
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Affiliation(s)
- Xihuimin Dai
- PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, Beijing Advanced Innovation Center for Genomics, Peking University School of Life Sciences, Beijing, China.,Chinese Institute for Brain Research, Beijing, China.,Howard Hughes Medical Institute, Department of Biology, Brandeis University, Waltham, MA
| | - Enxing Zhou
- PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, Beijing Advanced Innovation Center for Genomics, Peking University School of Life Sciences, Beijing, China
| | - Wei Yang
- PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, Beijing Advanced Innovation Center for Genomics, Peking University School of Life Sciences, Beijing, China.,Chinese Institute for Brain Research, Beijing, China
| | - Renbo Mao
- Graduate School of Peking Union Medical College, Beijing, China.,National Institute of Biological Sciences, Beijing, China
| | - Wenxia Zhang
- PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, Beijing Advanced Innovation Center for Genomics, Peking University School of Life Sciences, Beijing, China
| | - Yi Rao
- PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, Beijing Advanced Innovation Center for Genomics, Peking University School of Life Sciences, Beijing, China.,Chinese Institute for Brain Research, Beijing, China
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44
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Qiu S, Sun K, Di Z. Collective Dynamics of Neural Networks With Sleep-Related Biological Drives in Drosophila. Front Comput Neurosci 2021; 15:616193. [PMID: 34012388 PMCID: PMC8126628 DOI: 10.3389/fncom.2021.616193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Accepted: 03/29/2021] [Indexed: 11/18/2022] Open
Abstract
The collective electrophysiological dynamics of the brain as a result of sleep-related biological drives in Drosophila are investigated in this paper. Based on the Huber-Braun thermoreceptor model, the conductance-based neurons model is extended to a coupled neural network to analyze the local field potential (LFP). The LFP is calculated by using two different metrics: the mean value and the distance-dependent LFP. The distribution of neurons around the electrodes is assumed to have a circular or grid distribution on a two-dimensional plane. Regardless of which method is used, qualitatively similar results are obtained that are roughly consistent with the experimental data. During wake, the LFP has an irregular or a regular spike. However, the LFP becomes regular bursting during sleep. To further analyze the results, wavelet analysis and raster plots are used to examine how the LFP frequencies changed. The synchronization of neurons under different network structures is also studied. The results demonstrate that there are obvious oscillations at approximately 8 Hz during sleep that are absent during wake. Different time series of the LFP can be obtained under different network structures and the density of the network will also affect the magnitude of the potential. As the number of coupled neurons increases, the neural network becomes easier to synchronize, but the sleep and wake time described by the LFP spectrogram do not change. Moreover, the parameters that affect the durations of sleep and wake are analyzed.
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Affiliation(s)
- Shuihan Qiu
- International Academic Center of Complex Systems, Beijing Normal University at Zhuhai, Beijing, China.,School of Systems Science, Beijing Normal University, Beijing, China
| | - Kaijia Sun
- School of Systems Science, Beijing Normal University, Beijing, China
| | - Zengru Di
- International Academic Center of Complex Systems, Beijing Normal University at Zhuhai, Beijing, China.,School of Systems Science, Beijing Normal University, Beijing, China
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45
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Hanson A. Spontaneous electrical low-frequency oscillations: a possible role in Hydra and all living systems. Philos Trans R Soc Lond B Biol Sci 2021; 376:20190763. [PMID: 33487108 PMCID: PMC7934974 DOI: 10.1098/rstb.2019.0763] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/17/2020] [Indexed: 12/20/2022] Open
Abstract
As one of the first model systems in biology, the basal metazoan Hydra has been revealing fundamental features of living systems since it was first discovered by Antonie van Leeuwenhoek in the early eighteenth century. While it has become well-established within cell and developmental biology, this tiny freshwater polyp is only now being re-introduced to modern neuroscience where it has already produced a curious finding: the presence of low-frequency spontaneous neural oscillations at the same frequency as those found in the default mode network in the human brain. Surprisingly, increasing evidence suggests such spontaneous electrical low-frequency oscillations (SELFOs) are found across the wide diversity of life on Earth, from bacteria to humans. This paper reviews the evidence for SELFOs in diverse phyla, beginning with the importance of their discovery in Hydra, and hypothesizes a potential role as electrical organism organizers, which supports a growing literature on the role of bioelectricity as a 'template' for developmental memory in organism regeneration. This article is part of the theme issue 'Basal cognition: conceptual tools and the view from the single cell'.
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Affiliation(s)
- Alison Hanson
- Neurotechnology Center, Department of Biological Sciences, Columbia University, New York, NY, USA
- Department of Psychiatry, New York State Psychiatric Institute, Columbia University, New York, NY, USA
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46
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Frank MG. Challenging sleep homeostasis. Neurobiol Sleep Circadian Rhythms 2021; 10:100060. [PMID: 33604491 PMCID: PMC7872964 DOI: 10.1016/j.nbscr.2021.100060] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 11/22/2022] Open
Abstract
In this commentary, I play the Devil’s advocate and assume the title of High Contrarian. I intend to be provocative to challenge long-standing ideas about sleep. I blame all on Professor Craig Heller, who taught me to think this way as a graduate student in his laboratory. Scientists should fearlessly jump into the foaming edge of what we know, but also consider how safe are their intellectual harbors. There are many ideas we accept as ‘known’: that sleep is ubiquitous in the animal kingdom, that it serves vital functions, that it plays an essential role in brain plasticity. All of this could be wrong. As one example, I reexamine the idea that sleep is regulated by a mysterious ‘homeostat’ that determines sleep need based on prior wake time.
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Affiliation(s)
- Marcos G Frank
- Washington State University Spokane, Elson S. Floyd College of Medicine, Pharmaceutical and Biomedical Science Building 213, 412 E. Spokane Falls Blvd, Spokane, WA, 99202, USA
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47
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Abstract
Sleep is critical for diverse aspects of brain function in animals ranging from invertebrates to humans. Powerful genetic tools in the fruit fly Drosophila melanogaster have identified - at an unprecedented level of detail - genes and neural circuits that regulate sleep. This research has revealed that the functions and neural principles of sleep regulation are largely conserved from flies to mammals. Further, genetic approaches to studying sleep have uncovered mechanisms underlying the integration of sleep and many different biological processes, including circadian timekeeping, metabolism, social interactions, and aging. These findings show that in flies, as in mammals, sleep is not a single state, but instead consists of multiple physiological and behavioral states that change in response to the environment, and is shaped by life history. Here, we review advances in the study of sleep in Drosophila, discuss their implications for understanding the fundamental functions of sleep that are likely to be conserved among animal species, and identify important unanswered questions in the field.
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Affiliation(s)
- Orie T Shafer
- The Advanced Science Research Center, City University of New York, New York, NY 10031, USA.
| | - Alex C Keene
- Department of Biological Science, Florida Atlantic University, Jupiter, FL 33458, USA.
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48
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van Alphen B, Semenza ER, Yap M, van Swinderen B, Allada R. A deep sleep stage in Drosophila with a functional role in waste clearance. SCIENCE ADVANCES 2021; 7:7/4/eabc2999. [PMID: 33523916 PMCID: PMC7817094 DOI: 10.1126/sciadv.abc2999] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 12/02/2020] [Indexed: 06/12/2023]
Abstract
Sleep is a highly conserved state, suggesting that sleep's benefits outweigh the increased vulnerability it brings. Yet, little is known about how sleep fulfills its functions. Here, we used video tracking in tethered flies to identify a discrete deep sleep stage in Drosophila, termed proboscis extension sleep, that is defined by repeated stereotyped proboscis extensions and retractions. Proboscis extension sleep is accompanied by highly elevated arousal thresholds and decreased brain activity, indicative of a deep sleep state. Preventing proboscis extensions increases injury-related mortality and reduces waste clearance. Sleep deprivation reduces waste clearance and during subsequent rebound sleep, sleep, proboscis extensions, and waste clearance are increased. Together, these results provide evidence of a discrete deep sleep stage that is linked to a specific function and suggest that waste clearance is a core and ancient function of deep sleep.
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Affiliation(s)
- Bart van Alphen
- The Department of Neurobiology, Northwestern University, 2205 Tech Drive, Hogan 2-160, Evanston, Illinois 60208, USA.
| | - Evan R Semenza
- The Department of Neurobiology, Northwestern University, 2205 Tech Drive, Hogan 2-160, Evanston, Illinois 60208, USA
| | - Melvyn Yap
- The Queensland Brain Institute, QBI Building, 79, The University of Queensland, St. Lucia QLD 4072, Australia
| | - Bruno van Swinderen
- The Queensland Brain Institute, QBI Building, 79, The University of Queensland, St. Lucia QLD 4072, Australia
| | - Ravi Allada
- The Department of Neurobiology, Northwestern University, 2205 Tech Drive, Hogan 2-160, Evanston, Illinois 60208, USA.
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49
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Öztürk-Çolak A, Inami S, Buchler JR, McClanahan PD, Cruz A, Fang-Yen C, Koh K. Sleep Induction by Mechanosensory Stimulation in Drosophila. Cell Rep 2020; 33:108462. [PMID: 33264620 PMCID: PMC7735403 DOI: 10.1016/j.celrep.2020.108462] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 09/11/2020] [Accepted: 11/10/2020] [Indexed: 12/11/2022] Open
Abstract
People tend to fall asleep when gently rocked or vibrated. Experimental studies have shown that rocking promotes sleep in humans and mice. However, the mechanisms underlying the phenomenon are not well understood. A habituation model proposes that habituation, a form of non-associative learning, mediates sleep induction by monotonous stimulation. Here, we show that gentle vibration promotes sleep in Drosophila in part through habituation. Vibration-induced sleep (VIS) leads to increased homeostatic sleep credit and reduced arousability, and can be suppressed by heightened arousal or reduced GABA signaling. Multiple mechanosensory organs mediate VIS, and the magnitude of VIS depends on vibration frequency and genetic background. Sleep induction improves over successive blocks of vibration. Furthermore, training with continuous vibration does not generalize to intermittent vibration, demonstrating stimulus specificity, a characteristic of habituation. Our findings suggest that habituation plays a significant role in sleep induction by vibration. Öztürk-Çolak et al. demonstrate that gentle vibration induces sleep in Drosophila. The authors show that sleep induction improves over multiple vibration sessions, which suggests that habituation, a form of simple learning, plays a significant role in vibration-induced sleep.
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Affiliation(s)
- Arzu Öztürk-Çolak
- Department of Neuroscience, Jefferson Center for Synaptic Biology, and the Farber Institute for Neurosciences, Thomas Jefferson University, Philadelphia, PA 19106, USA
| | - Sho Inami
- Department of Neuroscience, Jefferson Center for Synaptic Biology, and the Farber Institute for Neurosciences, Thomas Jefferson University, Philadelphia, PA 19106, USA
| | - Joseph R Buchler
- Department of Neuroscience, Jefferson Center for Synaptic Biology, and the Farber Institute for Neurosciences, Thomas Jefferson University, Philadelphia, PA 19106, USA
| | - Patrick D McClanahan
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Andri Cruz
- Department of Neuroscience, Jefferson Center for Synaptic Biology, and the Farber Institute for Neurosciences, Thomas Jefferson University, Philadelphia, PA 19106, USA
| | - Christopher Fang-Yen
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kyunghee Koh
- Department of Neuroscience, Jefferson Center for Synaptic Biology, and the Farber Institute for Neurosciences, Thomas Jefferson University, Philadelphia, PA 19106, USA.
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50
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Tainton-Heap LAL, Kirszenblat LC, Notaras ET, Grabowska MJ, Jeans R, Feng K, Shaw PJ, van Swinderen B. A Paradoxical Kind of Sleep in Drosophila melanogaster. Curr Biol 2020; 31:578-590.e6. [PMID: 33238155 DOI: 10.1016/j.cub.2020.10.081] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 09/14/2020] [Accepted: 10/27/2020] [Indexed: 01/01/2023]
Abstract
The dynamic nature of sleep in many animals suggests distinct stages that serve different functions. Genetic sleep induction methods in animal models provide a powerful way to disambiguate these stages and functions, although behavioral methods alone are insufficient to accurately identify what kind of sleep is being engaged. In Drosophila, activation of the dorsal fan-shaped body (dFB) promotes sleep, but it remains unclear what kind of sleep this is, how the rest of the fly brain is behaving, or if any specific sleep functions are being achieved. Here, we developed a method to record calcium activity from thousands of neurons across a volume of the fly brain during spontaneous sleep and compared this to dFB-induced sleep. We found that spontaneous sleep typically transitions from an active "wake-like" stage to a less active stage. In contrast, optogenetic activation of the dFB promotes sustained wake-like levels of neural activity even though flies become unresponsive to mechanical stimuli. When we probed flies with salient visual stimuli, we found that the activity of visually responsive neurons in the central brain was blocked by transient dFB activation, confirming an acute disconnect from the external environment. Prolonged optogenetic dFB activation nevertheless achieved a key sleep function by correcting visual attention defects brought on by sleep deprivation. These results suggest that dFB activation promotes a distinct form of sleep in Drosophila, where brain activity appears similar to wakefulness, but responsiveness to external sensory stimuli is profoundly suppressed.
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Affiliation(s)
- Lucy A L Tainton-Heap
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Leonie C Kirszenblat
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia; RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Eleni T Notaras
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Martyna J Grabowska
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Rhiannon Jeans
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Kai Feng
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Paul J Shaw
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Bruno van Swinderen
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia.
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