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Luppi PH, Malcey J, Chancel A, Duval B, Cabrera S, Fort P. Neuronal network controlling REM sleep. J Sleep Res 2024:e14266. [PMID: 38972672 DOI: 10.1111/jsr.14266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2024] [Accepted: 05/27/2024] [Indexed: 07/09/2024]
Abstract
Rapid eye movement sleep is a state characterized by concomitant occurrence of rapid eye movements, electroencephalographic activation and muscle atonia. In this review, we provide up to date knowledge on the neuronal network controlling its onset and maintenance. It is now accepted that muscle atonia during rapid eye movement sleep is due to activation of glutamatergic neurons localized in the pontine sublaterodorsal tegmental nucleus. These neurons directly project and excite glycinergic/γ-aminobutyric acid-ergic pre-motoneurons localized in the ventromedial medulla. The sublaterodorsal tegmental nucleus rapid eye movement-on neurons are inactivated during wakefulness and non-rapid eye movement by rapid eye movement-off γ-aminobutyric acid-ergic neurons localized in the ventrolateral periaqueductal grey and the adjacent dorsal deep mesencephalic reticular nucleus. Melanin-concentrating hormone and γ-aminobutyric acid-ergic rapid eye movement sleep-on neurons localized in the lateral hypothalamus would inhibit these rapid eye movement sleep-off neurons initiating the state. Finally, the activation of a few limbic cortical structures during rapid eye movement sleep by the claustrum and the supramammillary nucleus as well as that of the basolateral amygdala would be involved in the function(s) of rapid eye movement sleep. In summary, rapid eye movement sleep is generated by a brainstem generator controlled by forebrain structures involved in autonomic control.
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Affiliation(s)
- Pierre-Hervé Luppi
- INSERM, U1028; CNRS, UMR5292, Lyon Neuroscience Research Center, Team "Physiopathologie des réseaux neuronaux responsables du cycle veille-sommeil", Lyon, France
- University Lyon 1, Lyon, France
| | - Justin Malcey
- INSERM, U1028; CNRS, UMR5292, Lyon Neuroscience Research Center, Team "Physiopathologie des réseaux neuronaux responsables du cycle veille-sommeil", Lyon, France
- University Lyon 1, Lyon, France
| | - Amarine Chancel
- INSERM, U1028; CNRS, UMR5292, Lyon Neuroscience Research Center, Team "Physiopathologie des réseaux neuronaux responsables du cycle veille-sommeil", Lyon, France
- University Lyon 1, Lyon, France
| | - Blandine Duval
- INSERM, U1028; CNRS, UMR5292, Lyon Neuroscience Research Center, Team "Physiopathologie des réseaux neuronaux responsables du cycle veille-sommeil", Lyon, France
| | - Sébastien Cabrera
- INSERM, U1028; CNRS, UMR5292, Lyon Neuroscience Research Center, Team "Physiopathologie des réseaux neuronaux responsables du cycle veille-sommeil", Lyon, France
- University Lyon 1, Lyon, France
| | - Patrice Fort
- INSERM, U1028; CNRS, UMR5292, Lyon Neuroscience Research Center, Team "Physiopathologie des réseaux neuronaux responsables du cycle veille-sommeil", Lyon, France
- University Lyon 1, Lyon, France
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Luppi PH, Chancel A, Malcey J, Cabrera S, Fort P, Maciel RM. Which structure generates paradoxical (REM) sleep: The brainstem, the hypothalamus, the amygdala or the cortex? Sleep Med Rev 2024; 74:101907. [PMID: 38422648 DOI: 10.1016/j.smrv.2024.101907] [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: 09/18/2023] [Revised: 12/31/2023] [Accepted: 01/19/2024] [Indexed: 03/02/2024]
Abstract
Paradoxical or Rapid eye movement (REM) sleep (PS) is a state characterized by REMs, EEG activation and muscle atonia. In this review, we discuss the contribution of brainstem, hypothalamic, amygdalar and cortical structures in PS genesis. We propose that muscle atonia during PS is due to activation of glutamatergic neurons localized in the pontine sublaterodorsal tegmental nucleus (SLD) projecting to glycinergic/GABAergic pre-motoneurons localized in the ventro-medial medulla (vmM). The SLD PS-on neurons are inactivated during wakefulness and slow-wave sleep by PS-off GABAergic neurons localized in the ventrolateral periaqueductal gray (vPAG) and the adjacent deep mesencephalic reticular nucleus. Melanin concentrating hormone (MCH) and GABAergic PS-on neurons localized in the posterior hypothalamus would inhibit these PS-off neurons to initiate the state. Finally, the activation of a few limbic cortical structures during PS by the claustrum and the supramammillary nucleus as well as that of the basolateral amygdala would also contribute to PS expression. Accumulating evidence indicates that the activation of these limbic structures plays a role in memory consolidation and would communicate to the PS-generating structures the need for PS to process memory. In summary, PS generation is controlled by structures distributed from the cortex to the medullary level of the brain.
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Affiliation(s)
- Pierre-Hervé Luppi
- INSERM, U1028, CNRS, UMR5292, Lyon Neuroscience Research Center, SLEEP Team "Physiopathologie des réseaux neuronaux responsables du cycle veille-sommeil", Lyon, France; University Claude Bernard, Lyon 1, Lyon, France.
| | - Amarine Chancel
- INSERM, U1028, CNRS, UMR5292, Lyon Neuroscience Research Center, SLEEP Team "Physiopathologie des réseaux neuronaux responsables du cycle veille-sommeil", Lyon, France; University Claude Bernard, Lyon 1, Lyon, France
| | - Justin Malcey
- INSERM, U1028, CNRS, UMR5292, Lyon Neuroscience Research Center, SLEEP Team "Physiopathologie des réseaux neuronaux responsables du cycle veille-sommeil", Lyon, France; University Claude Bernard, Lyon 1, Lyon, France
| | - Sébastien Cabrera
- INSERM, U1028, CNRS, UMR5292, Lyon Neuroscience Research Center, SLEEP Team "Physiopathologie des réseaux neuronaux responsables du cycle veille-sommeil", Lyon, France; University Claude Bernard, Lyon 1, Lyon, France
| | - Patrice Fort
- INSERM, U1028, CNRS, UMR5292, Lyon Neuroscience Research Center, SLEEP Team "Physiopathologie des réseaux neuronaux responsables du cycle veille-sommeil", Lyon, France; University Claude Bernard, Lyon 1, Lyon, France
| | - Renato M Maciel
- INSERM, U1028, CNRS, UMR5292, Lyon Neuroscience Research Center, SLEEP Team "Physiopathologie des réseaux neuronaux responsables du cycle veille-sommeil", Lyon, France; University Claude Bernard, Lyon 1, Lyon, France
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3
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Schott AL, Baik J, Chung S, Weber F. A medullary hub for controlling REM sleep and pontine waves. Nat Commun 2023; 14:3922. [PMID: 37400467 DOI: 10.1038/s41467-023-39496-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 06/07/2023] [Indexed: 07/05/2023] Open
Abstract
Rapid-eye-movement (REM) sleep is a distinct behavioral state associated with vivid dreaming and memory processing. Phasic bursts of electrical activity, measurable as spike-like pontine (P)-waves, are a hallmark of REM sleep implicated in memory consolidation. However, the brainstem circuits regulating P-waves, and their interactions with circuits generating REM sleep, remain largely unknown. Here, we show that an excitatory population of dorsomedial medulla (dmM) neurons expressing corticotropin-releasing-hormone (CRH) regulates both REM sleep and P-waves in mice. Calcium imaging showed that dmM CRH neurons are selectively activated during REM sleep and recruited during P-waves, and opto- and chemogenetic experiments revealed that this population promotes REM sleep. Chemogenetic manipulation also induced prolonged changes in P-wave frequency, while brief optogenetic activation reliably triggered P-waves along with transiently accelerated theta oscillations in the electroencephalogram (EEG). Together, these findings anatomically and functionally delineate a common medullary hub for the regulation of both REM sleep and P-waves.
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Affiliation(s)
- Amanda L Schott
- Department of Neuroscience, Perelman School of Medicine, Chronobiology and Sleep Institute, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Justin Baik
- Department of Neuroscience, Perelman School of Medicine, Chronobiology and Sleep Institute, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Shinjae Chung
- Department of Neuroscience, Perelman School of Medicine, Chronobiology and Sleep Institute, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Franz Weber
- Department of Neuroscience, Perelman School of Medicine, Chronobiology and Sleep Institute, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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Sulaman BA, Wang S, Tyan J, Eban-Rothschild A. Neuro-orchestration of sleep and wakefulness. Nat Neurosci 2023; 26:196-212. [PMID: 36581730 DOI: 10.1038/s41593-022-01236-w] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 11/16/2022] [Indexed: 12/31/2022]
Abstract
Although considered an inactive state for centuries, sleep entails many active processes occurring at the cellular, circuit and organismal levels. Over the last decade, several key technological advances, including calcium imaging and optogenetic and chemogenetic manipulations, have facilitated a detailed understanding of the functions of different neuronal populations and circuits in sleep-wake regulation. Here, we present recent progress and summarize our current understanding of the circuitry underlying the initiation, maintenance and coordination of wakefulness, rapid eye movement sleep (REMS) and non-REMS (NREMS). We propose a de-arousal model for sleep initiation, in which the neuromodulatory milieu necessary for sleep initiation is achieved by engaging in repetitive pre-sleep behaviors that gradually reduce vigilance to the external environment and wake-promoting neuromodulatory tone. We also discuss how brain processes related to thermoregulation, hunger and fear intersect with sleep-wake circuits to control arousal. Lastly, we discuss controversies and lingering questions in the sleep field.
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Affiliation(s)
- Bibi A Sulaman
- Department of Psychology, University of Michigan, Ann Arbor, MI, USA
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA
| | - Su Wang
- Department of Psychology, University of Michigan, Ann Arbor, MI, USA
| | - Jean Tyan
- Department of Psychology, University of Michigan, Ann Arbor, MI, USA
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
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Nollet M, Franks NP, Wisden W. Understanding Sleep Regulation in Normal and Pathological Conditions, and Why It Matters. J Huntingtons Dis 2023; 12:105-119. [PMID: 37302038 PMCID: PMC10473105 DOI: 10.3233/jhd-230564] [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] [Accepted: 05/22/2023] [Indexed: 06/12/2023]
Abstract
Sleep occupies a peculiar place in our lives and in science, being both eminently familiar and profoundly enigmatic. Historically, philosophers, scientists and artists questioned the meaning and purpose of sleep. If Shakespeare's verses from MacBeth depicting "Sleep that soothes away all our worries" and "relieves the weary laborer and heals hurt minds" perfectly epitomize the alleviating benefits of sleep, it is only during the last two decades that the growing understanding of the sophisticated sleep regulatory mechanisms allows us to glimpse putative biological functions of sleep. Sleep control brings into play various brain-wide processes occurring at the molecular, cellular, circuit, and system levels, some of them overlapping with a number of disease-signaling pathways. Pathogenic processes, including mood disorders (e.g., major depression) and neurodegenerative illnesses such Huntington's or Alzheimer's diseases, can therefore affect sleep-modulating networks which disrupt the sleep-wake architecture, whereas sleep disturbances may also trigger various brain disorders. In this review, we describe the mechanisms underlying sleep regulation and the main hypotheses drawn about its functions. Comprehending sleep physiological orchestration and functions could ultimately help deliver better treatments for people living with neurodegenerative diseases.
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Affiliation(s)
- Mathieu Nollet
- UK Dementia Research Institute and Department of Life Sciences, Imperial College London, London, UK
| | - Nicholas P. Franks
- UK Dementia Research Institute and Department of Life Sciences, Imperial College London, London, UK
| | - William Wisden
- UK Dementia Research Institute and Department of Life Sciences, Imperial College London, London, UK
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Functional roles of REM sleep. Neurosci Res 2022; 189:44-53. [PMID: 36572254 DOI: 10.1016/j.neures.2022.12.009] [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: 12/14/2022] [Revised: 12/01/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022]
Abstract
Rapid eye movement (REM) sleep is an enigmatic and intriguing sleep state. REM sleep differs from non-REM sleep by its characteristic brain activity and from wakefulness by a reduced anti-gravity muscle tone. In addition to these key traits, diverse physiological phenomena appear across the whole body during REM sleep. However, it remains unclear whether these phenomena are the causes or the consequences of REM sleep. Experimental approaches using humans and animal models have gradually revealed the functional roles of REM sleep. Extensive efforts have been made to interpret the characteristic brain activity in the context of memory functions. Numerous physical and psychological functions of REM sleep have also been proposed. Moreover, REM sleep has been implicated in aspects of brain development. Here, we review the variety of functional roles of REM sleep, mainly as revealed by animal models. In addition, we discuss controversies regarding the functional roles of REM sleep.
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Time to reconsider REM density in sleep research. Clin Neurophysiol 2022; 137:63-65. [DOI: 10.1016/j.clinph.2022.02.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 01/25/2022] [Accepted: 02/17/2022] [Indexed: 11/19/2022]
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Stucynski JA, Schott AL, Baik J, Chung S, Weber F. Regulation of REM sleep by inhibitory neurons in the dorsomedial medulla. Curr Biol 2022; 32:37-50.e6. [PMID: 34735794 PMCID: PMC8752505 DOI: 10.1016/j.cub.2021.10.030] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 07/20/2021] [Accepted: 10/12/2021] [Indexed: 01/12/2023]
Abstract
The two major stages of mammalian sleep-rapid eye movement sleep (REMs) and non-REM sleep (NREMs)-are characterized by distinct brain rhythms ranging from millisecond to minute-long (infraslow) oscillations. The mechanisms controlling transitions between sleep stages and how they are synchronized with infraslow rhythms remain poorly understood. Using opto- and chemogenetic manipulation in mice, we show that GABAergic neurons in the dorsomedial medulla (dmM) promote the initiation and maintenance of REMs, in part through their projections to the dorsal and median raphe nuclei. Fiber photometry revealed that their activity is strongly increased during REMs and fluctuates during NREMs in close synchrony with infraslow oscillations in the sleep spindle band of the electroencephalogram. The phase of this rhythm influenced the latency and probability with which dmM activation induced REMs. Thus, dmM inhibitory neurons strongly promote REMs, and their slow activity fluctuations may coordinate the timing of REMs episodes with infraslow brain rhythms.
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Affiliation(s)
- Joseph A. Stucynski
- Department of Neuroscience, Perelman School of Medicine, Chronobiology and Sleep Institute, University of Pennsylvania, 3400 Civic Center Blvd, Philadelphia, PA 19104, USA
| | - Amanda L. Schott
- Department of Neuroscience, Perelman School of Medicine, Chronobiology and Sleep Institute, University of Pennsylvania, 3400 Civic Center Blvd, Philadelphia, PA 19104, USA
| | - Justin Baik
- Department of Neuroscience, Perelman School of Medicine, Chronobiology and Sleep Institute, University of Pennsylvania, 3400 Civic Center Blvd, Philadelphia, PA 19104, USA,Present address: Inscopix, 2462 Embarcadero Way, Palo Alto, CA 94303, USA
| | - Shinjae Chung
- Department of Neuroscience, Perelman School of Medicine, Chronobiology and Sleep Institute, University of Pennsylvania, 3400 Civic Center Blvd, Philadelphia, PA 19104, USA
| | - Franz Weber
- Department of Neuroscience, Perelman School of Medicine, Chronobiology and Sleep Institute, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, PA 19104, USA.
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Oesch LT, Adamantidis AR. How REM sleep shapes hypothalamic computations for feeding behavior. Trends Neurosci 2021; 44:990-1003. [PMID: 34663506 DOI: 10.1016/j.tins.2021.09.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 09/06/2021] [Accepted: 09/22/2021] [Indexed: 10/20/2022]
Abstract
The electrical activity of diverse brain cells is modulated across states of vigilance, namely wakefulness, non-rapid eye movement (NREM) sleep, and rapid eye movement (REM) sleep. Enhanced activity of neuronal circuits during NREM sleep impacts on subsequent awake behaviors, yet the significance of their activation, or lack thereof, during REM sleep remains unclear. This review focuses on feeding-promoting cells in the lateral hypothalamus (LH) that express the vesicular GABA and glycine transporter (vgat) as a model to further understand the impact of REM sleep on neural encoding of goal-directed behavior. It emphasizes both spatial and temporal aspects of hypothalamic cell dynamics across awake behaviors and REM sleep, and discusses a role for REM sleep in brain plasticity underlying energy homeostasis and behavioral optimization.
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Affiliation(s)
- Lukas T Oesch
- Zentrum für Experimentelle Neurologie, Department of Neurology, Inselspital University Hospital Bern, Bern, Switzerland; Department of Biomedical Research, University of Bern, Bern, Switzerland; Department of Neurobiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Antoine R Adamantidis
- Zentrum für Experimentelle Neurologie, Department of Neurology, Inselspital University Hospital Bern, Bern, Switzerland; Department of Biomedical Research, University of Bern, Bern, Switzerland.
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Meng Q, Tan X, Jiang C, Xiong Y, Yan B, Zhang J. Tracking Eye Movements During Sleep in Mice. Front Neurosci 2021; 15:616760. [PMID: 33716648 PMCID: PMC7947631 DOI: 10.3389/fnins.2021.616760] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 02/04/2021] [Indexed: 12/02/2022] Open
Abstract
Eye movement is not only for adjusting the visual field and maintaining the stability of visual information on the retina, but also provides an external manifestation of the cognitive status of the brain. Recent studies showed similarity in eye movement patterns between wakefulness and rapid eye movement (REM) sleep, indicating that the brain status of REM sleep likely resembles that of awake status. REM sleep in humans could be divided into phasic REM and tonic REM sleep according to the difference in eye movement frequencies. Mice are the most commonly used animal model for studying neuronal and molecular mechanisms underlying sleep. However, there was a lack of details for eye movement patterns during REM sleep, hence it remains unknown whether REM sleep can be further divided into different stages in mice. Here we developed a device combining electroencephalogram (EEG), electromyogram (EMG) as well as eye movements recording in mice to study the eye movement patterns during sleep. We implanted a magnet beneath the conjunctiva of eye and tracked eye movements using a magnetic sensor. The magnetic signals showed strong correlation with video-oculography in head-fixed mice, indicating that the magnetic signals reflect the direction and magnitude of eye movement. We also found that the magnet implanted beneath the conjunctiva exhibited good biocompatibility. Finally, we examined eye movement in sleep–wake cycle, and discriminated tonic REM and phasic REM according to the frequency of eye movements, finding that compared to tonic REM, phasic REM exhibited higher oscillation power at 0.50 Hz, and lower oscillation power at 1.50–7.25 Hz and 9.50–12.00 Hz. Our device allowed to simultaneously record EEG, EMG, and eye movements during sleep and wakefulness, providing a convenient and high temporal-spatial resolution tool for studying eye movements in sleep and other researches in mice.
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Affiliation(s)
- Qingshuo Meng
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Department of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Xinrong Tan
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Department of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Chengyong Jiang
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Department of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yanyu Xiong
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Department of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Biao Yan
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Department of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Jiayi Zhang
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Department of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, China
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A Discrete Glycinergic Neuronal Population in the Ventromedial Medulla That Induces Muscle Atonia during REM Sleep and Cataplexy in Mice. J Neurosci 2021; 41:1582-1596. [PMID: 33372061 DOI: 10.1523/jneurosci.0688-20.2020] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 12/13/2020] [Accepted: 12/15/2020] [Indexed: 12/20/2022] Open
Abstract
During rapid eye movement (REM) sleep, anti-gravity muscle tone and bodily movements are mostly absent, because somatic motoneurons are inhibited by descending inhibitory pathways. Recent studies showed that glycine/GABA neurons in the ventromedial medulla (VMM; GlyVMM neurons) play an important role in generating muscle atonia during REM sleep (REM-atonia). However, how these REM-atonia-inducing neurons interconnect with other neuronal populations has been unknown. In the present study, we first identified a specific subpopulation of GlyVMM neurons that play an important role in induction of REM-atonia by virus vector-mediated tracing in male mice in which glycinergic neurons expressed Cre recombinase. We found these neurons receive direct synaptic input from neurons in several brain stem regions, including glutamatergic neurons in the sublaterodorsal tegmental nucleus (SLD; GluSLD neurons). Silencing this circuit by specifically expressing tetanus toxin light chain (TeTNLC) resulted in REM sleep without atonia. This manipulation also caused a marked decrease in time spent in cataplexy-like episodes (CLEs) when applied to narcoleptic orexin-ataxin-3 mice. We also showed that GlyVMM neurons play an important role in maintenance of sleep. This present study identified a population of glycinergic neurons in the VMM that are commonly involved in REM-atonia and cataplexy.SIGNIFICANCE STATEMENT We identified a population of glycinergic neurons in the ventral medulla that plays an important role in inducing muscle atonia during rapid eye movement (REM) sleep. It sends axonal projections almost exclusively to motoneurons in the spinal cord and brain stem except to those that innervate extraocular muscles, while other glycinergic neurons in the same region also send projections to other regions including monoaminergic nuclei. Furthermore, these neurons receive direct inputs from several brainstem regions including glutamatergic neurons in the sublaterodorsal tegmental nucleus (SLD). Genetic silencing of this pathway resulted in REM sleep without atonia and a decrease of cataplexy when applied to narcoleptic mice. This work identified a neural population involved in generating muscle atonia during REM sleep and cataplexy.
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Girard F, von Siebenthal M, Davis FP, Celio MR. Gene expression analysis in the mouse brainstem identifies Cart and Nesfatin as neuropeptides coexpressed in the Calbindin-positive neurons of the Nucleus papilio. Sleep 2020; 43:5826369. [PMID: 32343818 PMCID: PMC7658639 DOI: 10.1093/sleep/zsaa085] [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: 12/11/2019] [Revised: 04/08/2020] [Indexed: 11/17/2022] Open
Abstract
Study Objectives: The brainstem contains several neuronal populations, heterogeneous in terms of neurotransmitter/neuropeptide content, which are important for controlling various aspects of the rapid eye movement (REM) phase of sleep. Among these populations are the Calbindin (Calb)-immunoreactive NPCalb neurons, located in the Nucleus papilio, within the dorsal paragigantocellular nucleus (DPGi), and recently shown to control eye movement during the REM phase of sleep. Methods: We performed in-depth data mining of the in situ hybridization data collected at the Allen Brain Atlas, in order to identify potentially interesting genes expressed in this brainstem nucleus. Our attention focused on genes encoding neuropeptides, including Cart (Cocaine and Amphetamine Regulated Transcripts) and Nesfatin 1. Results: While nesfatin 1 appeared ubiquitously expressed in this Calb-positive neuronal population, Cart was coexpressed in only a subset of these glutamatergic NPCalb neurons. Furthermore, an REM sleep deprivation and rebound assay performed with mice revealed that the Cart-positive neuronal population within the DPGi was activated during REM sleep (as measured by c-fos immunoreactivity), suggesting a role of this neuropeptide in regulating some aspects of REM sleep. Conclusions: The assembled information could afford functional clues to investigators, conducive to further experimental pursuits.
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Affiliation(s)
- Franck Girard
- Department of Medicine, Faculty of Science, University of Fribourg, Fribourg, Switzerland
| | | | - Fred P Davis
- Janelia-Farm Research Campus, Howard Hughes Medical Institute, Ashburn, VA
| | - Marco R Celio
- Department of Medicine, Faculty of Science, University of Fribourg, Fribourg, Switzerland
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Park SH, Weber F. Neural and Homeostatic Regulation of REM Sleep. Front Psychol 2020; 11:1662. [PMID: 32793050 PMCID: PMC7385183 DOI: 10.3389/fpsyg.2020.01662] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Accepted: 06/18/2020] [Indexed: 12/11/2022] Open
Abstract
Rapid eye movement (REM) sleep is a distinct, homeostatically controlled brain state characterized by an activated electroencephalogram (EEG) in combination with paralysis of skeletal muscles and is associated with vivid dreaming. Understanding how REM sleep is controlled requires identification of the neural circuits underlying its initiation and maintenance, and delineation of the homeostatic processes regulating its expression on multiple timescales. Soon after its discovery in humans in 1953, the pons was demonstrated to be necessary and sufficient for the generation of REM sleep. But, especially within the last decade, researchers have identified further neural populations in the hypothalamus, midbrain, and medulla that regulate REM sleep by either promoting or suppressing this brain state. The discovery of these populations was greatly facilitated by the availability of novel technologies for the dissection of neural circuits. Recent quantitative models integrate findings about the activity and connectivity of key neurons and knowledge about homeostatic mechanisms to explain the dynamics underlying the recurrence of REM sleep. For the future, combining quantitative with experimental approaches to directly test model predictions and to refine existing models will greatly advance our understanding of the neural and homeostatic processes governing the regulation of REM sleep.
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Affiliation(s)
| | - Franz Weber
- Department of Neuroscience, Perelman School of Medicine, Chronobiology and Sleep Institute, University of Pennsylvania, Philadelphia, PA, United States
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