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Kaller MS, Lazari A, Feng Y, van der Toorn A, Rühling S, Thomas CW, Shimizu T, Bannerman D, Vyazovskiy V, Richardson WD, Sampaio-Baptista C, Johansen-Berg H. Ablation of oligodendrogenesis in adult mice alters brain microstructure and activity independently of behavioral deficits. Glia 2024. [PMID: 38982743 DOI: 10.1002/glia.24576] [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: 10/13/2023] [Revised: 05/16/2024] [Accepted: 05/21/2024] [Indexed: 07/11/2024]
Abstract
Oligodendrocytes continue to differentiate from their precursor cells even in adulthood, a process that can be modulated by neuronal activity and experience. Previous work has indicated that conditional ablation of oligodendrogenesis in adult mice leads to learning and memory deficits in a range of behavioral tasks. The current study replicated and re-evaluated evidence for a role of oligodendrogenesis in motor learning, using a complex running wheel task. Further, we found that ablating oligodendrogenesis alters brain microstructure (ex vivo MRI) and brain activity (in vivo EEG) independent of experience with the task. This suggests a role for adult oligodendrocyte formation in the maintenance of brain function and indicates that task-independent changes due to oligodendrogenesis ablation need to be considered when interpreting learning and memory deficits in this model.
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Affiliation(s)
- Malte S Kaller
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Alberto Lazari
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Yingshi Feng
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Annette van der Toorn
- Biomedical MR Imaging and Spectroscopy Group, Center for Image Sciences, University Medical Center Utrecht & Utrecht University, Utrecht, The Netherlands
| | - Sebastian Rühling
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- Department of Diagnostic and Interventional Neuroradiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Christopher W Thomas
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Takahiro Shimizu
- The Wolfson Institute for Biomedical Research, University College London, London, UK
| | - David Bannerman
- Department of Experimental Psychology, University of Oxford, Oxford, UK
| | - Vladyslav Vyazovskiy
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
- Sir Jules Thorn Sleep and Circadian Neuroscience Institute, University of Oxford, Oxford, UK
- The Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford, UK
| | - William D Richardson
- The Wolfson Institute for Biomedical Research, University College London, London, UK
| | - Cassandra Sampaio-Baptista
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- School of Psychology and Neuroscience, University of Glasgow, Glasgow, UK
| | - Heidi Johansen-Berg
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
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2
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Benoit E, Lyons DG, Rihel J. Noradrenergic tone is not required for neuronal activity-induced rebound sleep in zebrafish. J Comp Physiol B 2024; 194:279-298. [PMID: 37480493 PMCID: PMC11233345 DOI: 10.1007/s00360-023-01504-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 07/03/2023] [Indexed: 07/24/2023]
Abstract
Sleep pressure builds during wakefulness, but the mechanisms underlying this homeostatic process are poorly understood. One zebrafish model suggests that sleep pressure increases as a function of global neuronal activity, such as during sleep deprivation or acute exposure to drugs that induce widespread brain activation. Given that the arousal-promoting noradrenergic system is important for maintaining heightened neuronal activity during wakefulness, we hypothesised that genetic and pharmacological reduction of noradrenergic tone during drug-induced neuronal activation would dampen subsequent rebound sleep in zebrafish larvae. During stimulant drug treatment, dampening noradrenergic tone with the α2-adrenoceptor agonist clonidine unexpectedly enhanced subsequent rebound sleep, whereas enhancing noradrenergic signalling with a cocktail of α1- and β-adrenoceptor agonists did not enhance rebound sleep. Similarly, CRISPR/Cas9-mediated elimination of the dopamine β-hydroxylase (dbh) gene, which encodes an enzyme required for noradrenalin synthesis, enhanced baseline sleep in larvae but did not prevent additional rebound sleep following acute induction of neuronal activity. Across all drug conditions, c-fos expression immediately after drug exposure correlated strongly with the amount of induced rebound sleep, but was inversely related to the strength of noradrenergic modulatory tone. These results are consistent with a model in which increases in neuronal activity, as reflected by brain-wide levels of c-fos induction, drive a sleep pressure signal that promotes rebound sleep independently of noradrenergic tone.
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Affiliation(s)
- Eleanor Benoit
- Department of Cell and Developmental Biology, University College London, London, WC1E 6BT, UK
| | - Declan G Lyons
- Department of Cell and Developmental Biology, University College London, London, WC1E 6BT, UK
| | - Jason Rihel
- Department of Cell and Developmental Biology, University College London, London, WC1E 6BT, UK.
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3
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Chang H, Esteves IM, Neumann AR, Mohajerani MH, McNaughton BL. Cortical reactivation of spatial and non-spatial features coordinates with hippocampus to form a memory dialogue. Nat Commun 2023; 14:7748. [PMID: 38012135 PMCID: PMC10682454 DOI: 10.1038/s41467-023-43254-7] [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: 02/16/2023] [Accepted: 11/03/2023] [Indexed: 11/29/2023] Open
Abstract
Episodic memories comprise diverse attributes of experience distributed across neocortical areas. The hippocampus is integral to rapidly binding these diffuse representations, as they occur, to be later reinstated. However, the nature of the information exchanged during this hippocampal-cortical dialogue remains poorly understood. A recent study has shown that the secondary motor cortex carries two types of representations: place cell-like activity, which were impaired by hippocampal lesions, and responses tied to visuo-tactile cues, which became more pronounced following hippocampal lesions. Using two-photon Ca2+ imaging to record neuronal activities in the secondary motor cortex of male Thy1-GCaMP6s mice, we assessed the cortical retrieval of spatial and non-spatial attributes from previous explorations in a virtual environment. We show that, following navigation, spontaneous resting state reactivations convey varying degrees of spatial (trajectory sequences) and non-spatial (visuo-tactile attributes) information, while reactivations of non-spatial attributes tend to precede reactivations of spatial representations surrounding hippocampal sharp-wave ripples.
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Affiliation(s)
- HaoRan Chang
- Canadian Centre for Behavioural Neuroscience, Department of Neuroscience, University of Lethbridge, 4401 University Drive, Lethbridge, T1K 3M4, AB, Canada.
| | - Ingrid M Esteves
- Canadian Centre for Behavioural Neuroscience, Department of Neuroscience, University of Lethbridge, 4401 University Drive, Lethbridge, T1K 3M4, AB, Canada
| | - Adam R Neumann
- Canadian Centre for Behavioural Neuroscience, Department of Neuroscience, University of Lethbridge, 4401 University Drive, Lethbridge, T1K 3M4, AB, Canada
| | - Majid H Mohajerani
- Canadian Centre for Behavioural Neuroscience, Department of Neuroscience, University of Lethbridge, 4401 University Drive, Lethbridge, T1K 3M4, AB, Canada
- Department of Psychiatry, Douglas Hospital Research Centre, McGill University, 6875 Boulevard LaSalle, Verdun, QC, H4H 1R3, Canada
| | - Bruce L McNaughton
- Canadian Centre for Behavioural Neuroscience, Department of Neuroscience, University of Lethbridge, 4401 University Drive, Lethbridge, T1K 3M4, AB, Canada
- Department of Neurobiology and Behavior, University of California, 2205 McGaugh Hall, Irvine, 92697, CA, USA
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4
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Marmelshtein A, Eckerling A, Hadad B, Ben-Eliyahu S, Nir Y. Sleep-like changes in neural processing emerge during sleep deprivation in early auditory cortex. Curr Biol 2023:S0960-9822(23)00773-X. [PMID: 37385257 DOI: 10.1016/j.cub.2023.06.022] [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: 04/05/2022] [Revised: 03/30/2023] [Accepted: 06/07/2023] [Indexed: 07/01/2023]
Abstract
Insufficient sleep is commonplace in modern lifestyle and can lead to grave outcomes, yet the changes in neuronal activity accumulating over hours of extended wakefulness remain poorly understood. Specifically, which aspects of cortical processing are affected by sleep deprivation (SD), and whether they also affect early sensory regions, remain unclear. Here, we recorded spiking activity in the rat auditory cortex along with polysomnography while presenting sounds during SD followed by recovery sleep. We found that frequency tuning, onset responses, and spontaneous firing rates were largely unaffected by SD. By contrast, SD decreased entrainment to rapid (≥20 Hz) click trains, increased population synchrony, and increased the prevalence of sleep-like stimulus-induced silent periods, even when ongoing activity was similar. Recovery NREM sleep was associated with similar effects as SD with even greater magnitude, while auditory processing during REM sleep was similar to vigilant wakefulness. Our results show that processes akin to those in NREM sleep invade the activity of cortical circuits during SD, even in the early sensory cortex.
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Affiliation(s)
- Amit Marmelshtein
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel; Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Anabel Eckerling
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel; School of Psychological Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Barak Hadad
- School of Electrical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Shamgar Ben-Eliyahu
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel; School of Psychological Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Yuval Nir
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel; Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel; Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 6997801, Israel; The Sieratzki-Sagol Center for Sleep Medicine, Tel Aviv Sourasky Medical Center, Tel Aviv 6423906, Israel.
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5
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Traut J, Mengual JP, Meijer EJ, McKillop LE, Alfonsa H, Hoerder-Suabedissen A, Song SH, Fehér KD, Riemann D, Molnar Z, Akerman CJ, Vyazovskiy VV, Krone LB. Effects of clozapine-N-oxide and compound 21 on sleep in laboratory mice. eLife 2023; 12:e84740. [PMID: 36892930 PMCID: PMC9998087 DOI: 10.7554/elife.84740] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 01/03/2023] [Indexed: 03/10/2023] Open
Abstract
Designer receptors exclusively activated by designer drugs (DREADDs) are chemogenetic tools for remote control of targeted cell populations using chemical actuators that bind to modified receptors. Despite the popularity of DREADDs in neuroscience and sleep research, potential effects of the DREADD actuator clozapine-N-oxide (CNO) on sleep have never been systematically tested. Here, we show that intraperitoneal injections of commonly used CNO doses (1, 5, and 10 mg/kg) alter sleep in wild-type male laboratory mice. Using electroencephalography (EEG) and electromyography (EMG) to analyse sleep, we found a dose-dependent suppression of rapid eye movement (REM) sleep, changes in EEG spectral power during non-REM (NREM) sleep, and altered sleep architecture in a pattern previously reported for clozapine. Effects of CNO on sleep could arise from back-metabolism to clozapine or binding to endogenous neurotransmitter receptors. Interestingly, we found that the novel DREADD actuator, compound 21 (C21, 3 mg/kg), similarly modulates sleep despite a lack of back-metabolism to clozapine. Our results demonstrate that both CNO and C21 can modulate sleep of mice not expressing DREADD receptors. This implies that back-metabolism to clozapine is not the sole mechanism underlying side effects of chemogenetic actuators. Therefore, any chemogenetic experiment should include a DREADD-free control group injected with the same CNO, C21, or newly developed actuator. We suggest that electrophysiological sleep assessment could serve as a sensitive tool to test the biological inertness of novel chemogenetic actuators.
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Affiliation(s)
- Janine Traut
- Department of Psychiatry and Psychotherapy, Medical Center - University of Freiburg, Faculty of Medicine, University of FreiburgFreiburgGermany
- Department of Physiology, Anatomy and Genetics, University of OxfordOxfordUnited Kingdom
- Sir Jules Thorn Sleep and Circadian Neuroscience Institute, University of OxfordOxfordUnited Kingdom
| | - Jose Prius Mengual
- Department of Physiology, Anatomy and Genetics, University of OxfordOxfordUnited Kingdom
- Sir Jules Thorn Sleep and Circadian Neuroscience Institute, University of OxfordOxfordUnited Kingdom
- The Kavli Institute for Nanoscience DiscoveryOxfordUnited Kingdom
| | - Elise J Meijer
- Department of Physiology, Anatomy and Genetics, University of OxfordOxfordUnited Kingdom
- Sir Jules Thorn Sleep and Circadian Neuroscience Institute, University of OxfordOxfordUnited Kingdom
- The Kavli Institute for Nanoscience DiscoveryOxfordUnited Kingdom
| | - Laura E McKillop
- Department of Physiology, Anatomy and Genetics, University of OxfordOxfordUnited Kingdom
- Sir Jules Thorn Sleep and Circadian Neuroscience Institute, University of OxfordOxfordUnited Kingdom
| | - Hannah Alfonsa
- Department of Pharmacology, University of OxfordOxfordUnited Kingdom
| | | | - Seo Ho Song
- Department of Psychiatry, Beth Israel Deaconess Medical Center, Harvard Medical SchoolBostonUnited States
| | - Kristoffer D Fehér
- Geneva University Hospitals (HUG), Division of Psychiatric SpecialtiesGenevaSwitzerland
- University Hospital of Psychiatry and Psychotherapy, University of BernBernSwitzerland
| | - Dieter Riemann
- Department of Psychiatry and Psychotherapy, Medical Center - University of Freiburg, Faculty of Medicine, University of FreiburgFreiburgGermany
- Sir Jules Thorn Sleep and Circadian Neuroscience Institute, University of OxfordOxfordUnited Kingdom
| | - Zoltan Molnar
- Department of Physiology, Anatomy and Genetics, University of OxfordOxfordUnited Kingdom
| | - Colin J Akerman
- Department of Pharmacology, University of OxfordOxfordUnited Kingdom
| | - Vladyslav V Vyazovskiy
- Department of Physiology, Anatomy and Genetics, University of OxfordOxfordUnited Kingdom
- Sir Jules Thorn Sleep and Circadian Neuroscience Institute, University of OxfordOxfordUnited Kingdom
- The Kavli Institute for Nanoscience DiscoveryOxfordUnited Kingdom
| | - Lukas B Krone
- Department of Physiology, Anatomy and Genetics, University of OxfordOxfordUnited Kingdom
- Sir Jules Thorn Sleep and Circadian Neuroscience Institute, University of OxfordOxfordUnited Kingdom
- The Kavli Institute for Nanoscience DiscoveryOxfordUnited Kingdom
- University Hospital of Psychiatry and Psychotherapy, University of BernBernSwitzerland
- Centre for Experimental Neurology, University of BernBernSwitzerland
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6
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Detection of neuronal OFF periods as low amplitude neural activity segments. BMC Neurosci 2023; 24:13. [PMID: 36809980 PMCID: PMC9942432 DOI: 10.1186/s12868-023-00780-w] [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: 11/30/2022] [Accepted: 01/27/2023] [Indexed: 02/23/2023] Open
Abstract
BACKGROUND During non-rapid eye movement sleep (NREM), alternating periods of synchronised high (ON period) and low (OFF period) neuronal activity are associated with high amplitude delta band (0.5-4 Hz) oscillations in neocortical electrophysiological signals termed slow waves. As this oscillation is dependent crucially on hyperpolarisation of cortical cells, there is an interest in understanding how neuronal silencing during OFF periods leads to the generation of slow waves and whether this relationship changes between cortical layers. A formal, widely adopted definition of OFF periods is absent, complicating their detection. Here, we grouped segments of high frequency neural activity containing spikes, recorded as multiunit activity from the neocortex of freely behaving mice, on the basis of amplitude and asked whether the population of low amplitude (LA) segments displayed the expected characteristics of OFF periods. RESULTS Average LA segment length was comparable to previous reports for OFF periods but varied considerably, from as short as 8 ms to > 1 s. LA segments were longer and occurred more frequently in NREM but shorter LA segments also occurred in half of rapid eye movement sleep (REM) epochs and occasionally during wakefulness. LA segments in all states were associated with a local field potential (LFP) slow wave that increased in amplitude with LA segment duration. We found that LA segments > 50 ms displayed a homeostatic rebound in incidence following sleep deprivation whereas short LA segments (< 50 ms) did not. The temporal organisation of LA segments was more coherent between channels located at a similar cortical depth. CONCLUSION We corroborate previous studies showing neural activity signals contain uniquely identifiable periods of low amplitude with distinct characteristics from the surrounding signal known as OFF periods and attribute the new characteristics of vigilance-state-dependent duration and duration-dependent homeostatic response to this phenomenon. This suggests that ON/OFF periods are currently underdefined and that their appearance is less binary than previously considered, instead representing a continuum.
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7
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Kahn M, Krone LB, Blanco‐Duque C, Guillaumin MCC, Mann EO, Vyazovskiy VV. Neuronal-spiking-based closed-loop stimulation during cortical ON- and OFF-states in freely moving mice. J Sleep Res 2022; 31:e13603. [PMID: 35665551 PMCID: PMC9786831 DOI: 10.1111/jsr.13603] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 02/20/2022] [Accepted: 03/22/2022] [Indexed: 12/30/2022]
Abstract
The slow oscillation is a central neuronal dynamic during sleep, and is generated by alternating periods of high and low neuronal activity (ON- and OFF-states). Mounting evidence causally links the slow oscillation to sleep's functions, and it has recently become possible to manipulate the slow oscillation non-invasively and phase-specifically. These developments represent promising clinical avenues, but they also highlight the importance of improving our understanding of how ON/OFF-states affect incoming stimuli and what role they play in neuronal plasticity. Most studies using closed-loop stimulation rely on the electroencephalogram and local field potential signals, which reflect neuronal ON- and OFF-states only indirectly. Here we develop an online detection algorithm based on spiking activity recorded from laminar arrays in mouse motor cortex. We find that online detection of ON- and OFF-states reflects specific phases of spontaneous local field potential slow oscillation. Our neuronal-spiking-based closed-loop procedure offers a novel opportunity for testing the functional role of slow oscillation in sleep-related restorative processes and neural plasticity.
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Affiliation(s)
- Martin Kahn
- Department of PhysiologyAnatomy and Genetics, University of OxfordOxfordUK,Sleep and Circadian Neuroscience InstituteUniversity of OxfordOxfordUK
| | - Lukas B. Krone
- Department of PhysiologyAnatomy and Genetics, University of OxfordOxfordUK,Sleep and Circadian Neuroscience InstituteUniversity of OxfordOxfordUK,University Hospital of Psychiatry and PsychotherapyUniversity of BernBernSwitzerland,Centre for Experimental NeurologyUniversity of BernBernSwitzerland
| | - Cristina Blanco‐Duque
- Department of PhysiologyAnatomy and Genetics, University of OxfordOxfordUK,Sleep and Circadian Neuroscience InstituteUniversity of OxfordOxfordUK
| | - Mathilde C. C. Guillaumin
- Sleep and Circadian Neuroscience InstituteUniversity of OxfordOxfordUK,Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUK,Department of Health Sciences and TechnologyInstitute for NeuroscienceETH, ZurichSwitzerland
| | - Edward O. Mann
- Department of PhysiologyAnatomy and Genetics, University of OxfordOxfordUK
| | - Vladyslav V. Vyazovskiy
- Department of PhysiologyAnatomy and Genetics, University of OxfordOxfordUK,Sleep and Circadian Neuroscience InstituteUniversity of OxfordOxfordUK
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8
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Dastgheib M, Kulanayagam A, Dringenberg HC. Is the role of sleep in memory consolidation overrated? Neurosci Biobehav Rev 2022; 140:104799. [PMID: 35905801 DOI: 10.1016/j.neubiorev.2022.104799] [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: 03/11/2022] [Revised: 06/13/2022] [Accepted: 07/25/2022] [Indexed: 11/18/2022]
Abstract
Substantial empirical evidence suggests that sleep benefits the consolidation and reorganization of learned information. Consequently, the concept of "sleep-dependent memory consolidation" is now widely accepted by the scientific community, in addition to influencing public perceptions regarding the functions of sleep. There are, however, numerous studies that have presented findings inconsistent with the sleep-memory hypothesis. Here, we challenge the notion of "sleep-dependency" by summarizing evidence for effective memory consolidation independent of sleep. Plasticity mechanisms thought to mediate or facilitate consolidation during sleep (e.g., neuronal replay, reactivation, slow oscillations, neurochemical milieu) also operate during non-sleep states, particularly quiet wakefulness, thus allowing for the stabilization of new memories. We propose that it is not sleep per se, but the engagement of plasticity mechanisms, active during both sleep and (at least some) waking states, that constitutes the critical factor determining memory formation. Thus, rather than playing a "critical" role, sleep falls along a continuum of behavioral states that vary in their effectiveness to support memory consolidation at the neural and behavioral level.
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Affiliation(s)
| | | | - Hans C Dringenberg
- Department of Psychology, Queen's University, Kingston, Ontario, Canada.
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9
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Christensen AJ, Pillow JW. Reduced neural activity but improved coding in rodent higher-order visual cortex during locomotion. Nat Commun 2022; 13:1676. [PMID: 35354804 PMCID: PMC8967903 DOI: 10.1038/s41467-022-29200-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 03/04/2022] [Indexed: 11/19/2022] Open
Abstract
Running profoundly alters stimulus-response properties in mouse primary visual cortex (V1), but its effect in higher-order visual cortex is under-explored. Here we systematically investigate how visual responses vary with locomotive state across six visual areas and three cortical layers using a massive dataset from the Allen Brain Institute. Although previous work has shown running speed to be positively correlated with neural activity in V1, here we show that the sign of correlations between speed and neural activity varies across extra-striate cortex, and is even negative in anterior extra-striate cortex. Nevertheless, across all visual cortices, neural responses can be decoded more accurately during running than during stationary periods. We show that this effect is not attributable to changes in population activity structure, and propose that it instead arises from an increase in reliability of single-neuron responses during locomotion. The authors analyze the Allen Institute Brain Observatory Ca2+ imaging data, focusing on mouse visual cortex during locomotive and quiescent states. They find that locomotion increases neural coding fidelity, regardless of whether population activity increases or decreases in response to the population’s preferred stimuli.
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Affiliation(s)
| | - Jonathan W Pillow
- Princeton Neuroscience Institute & Department of Psychology, Princeton University, Princeton, NJ, USA
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10
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Thomas CW, Blanco-Duque C, Bréant BJ, Goodwin GM, Sharp T, Bannerman DM, Vyazovskiy VV. Psilocin acutely alters sleep-wake architecture and cortical brain activity in laboratory mice. Transl Psychiatry 2022; 12:77. [PMID: 35197453 PMCID: PMC8866416 DOI: 10.1038/s41398-022-01846-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 02/02/2022] [Accepted: 02/03/2022] [Indexed: 01/03/2023] Open
Abstract
Serotonergic psychedelic drugs, such as psilocin (4-hydroxy-N,N-dimethyltryptamine), profoundly alter the quality of consciousness through mechanisms which are incompletely understood. Growing evidence suggests that a single psychedelic experience can positively impact long-term psychological well-being, with relevance for the treatment of psychiatric disorders, including depression. A prominent factor associated with psychiatric disorders is disturbed sleep, and the sleep-wake cycle is implicated in the homeostatic regulation of neuronal activity and synaptic plasticity. However, it remains largely unknown to what extent psychedelic agents directly affect sleep, in terms of both acute arousal and homeostatic sleep regulation. Here, chronic electrophysiological recordings were obtained in mice to track sleep-wake architecture and cortical activity after psilocin injection. Administration of psilocin led to delayed REM sleep onset and reduced NREM sleep maintenance for up to approximately 3 h after dosing, and the acute EEG response was associated primarily with an enhanced oscillation around 4 Hz. No long-term changes in sleep-wake quantity were found. When combined with sleep deprivation, psilocin did not alter the dynamics of homeostatic sleep rebound during the subsequent recovery period, as reflected in both sleep amount and EEG slow-wave activity. However, psilocin decreased the recovery rate of sleep slow-wave activity following sleep deprivation in the local field potentials of electrodes targeting the medial prefrontal and surrounding cortex. It is concluded that psilocin affects both global vigilance state control and local sleep homeostasis, an effect which may be relevant for its antidepressant efficacy.
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Affiliation(s)
- Christopher W. Thomas
- grid.4991.50000 0004 1936 8948Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Cristina Blanco-Duque
- grid.4991.50000 0004 1936 8948Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Benjamin J. Bréant
- grid.4991.50000 0004 1936 8948Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Guy M. Goodwin
- grid.4991.50000 0004 1936 8948Department of Psychiatry, University of Oxford, Oxford, UK
| | - Trevor Sharp
- grid.4991.50000 0004 1936 8948Department of Pharmacology, University of Oxford, Oxford, UK
| | - David M. Bannerman
- grid.4991.50000 0004 1936 8948Department of Experimental Psychology, University of Oxford, Oxford, UK
| | - Vladyslav V. Vyazovskiy
- grid.4991.50000 0004 1936 8948Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
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11
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Input rate encoding and gain control in dendrites of neocortical pyramidal neurons. Cell Rep 2022; 38:110382. [PMID: 35172157 PMCID: PMC8967317 DOI: 10.1016/j.celrep.2022.110382] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 11/15/2021] [Accepted: 01/23/2022] [Indexed: 01/06/2023] Open
Abstract
Elucidating how neurons encode network activity is essential to understanding how the brain processes information. Neocortical pyramidal cells receive excitatory input onto spines distributed along dendritic branches. Local dendritic branch nonlinearities can boost the response to spatially clustered and synchronous input, but how this translates into the integration of patterns of ongoing activity remains unclear. To examine dendritic integration under naturalistic stimulus regimes, we use two-photon glutamate uncaging to repeatedly activate multiple dendritic spines at random intervals. In the proximal dendrites of two populations of layer 5 pyramidal neurons in the mouse motor cortex, spatially restricted synchrony is not a prerequisite for dendritic boosting. Branches encode afferent inputs with distinct rate sensitivities depending upon cell and branch type. Thus, inputs distributed along a dendritic branch can recruit supralinear boosting and the window of this nonlinearity may provide a mechanism by which dendrites can preferentially amplify slow-frequency network oscillations.
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12
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Béland-Millar A, Messier C. Voluntary Behavior and Training Conditions Modulate in vivo Extracellular Glucose and Lactate in the Mouse Primary Motor Cortex. Front Neurosci 2022; 15:732242. [PMID: 35058739 PMCID: PMC8764159 DOI: 10.3389/fnins.2021.732242] [Citation(s) in RCA: 1] [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: 06/28/2021] [Accepted: 11/10/2021] [Indexed: 11/13/2022] Open
Abstract
Learning or performing new behaviors requires significant neuronal signaling and is metabolically demanding. The metabolic cost of performing a behavior is mitigated by exposure and practice which result in diminished signaling and metabolic requirements. We examined the impact of novel and habituated wheel running, as well as effortful behaviors on the modulation of extracellular glucose and lactate using biosensors inserted in the primary motor cortex of mice. We found that motor behaviors produce increases in extracellular lactate and decreases in extracellular glucose in the primary motor cortex. These effects were modulated by experience, novelty and intensity of the behavior. The increase in extracellular lactate appears to be strongly associated with novelty of a behavior as well as the difficulty of performing a behavior. Our observations are consistent with the view that a main function of aerobic glycolysis is not to fuel the current neuronal activity but to sustain new bio-infrastructure as learning changes neural networks, chiefly through the shuttling of glucose derived carbons into the pentose phosphate pathway for the biosynthesis of nucleotides.
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Affiliation(s)
| | - Claude Messier
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
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13
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Yamagata T, Kahn MC, Prius-Mengual J, Meijer E, Šabanović M, Guillaumin MCC, van der Vinne V, Huang YG, McKillop LE, Jagannath A, Peirson SN, Mann EO, Foster RG, Vyazovskiy VV. The hypothalamic link between arousal and sleep homeostasis in mice. Proc Natl Acad Sci U S A 2021; 118:e2101580118. [PMID: 34903646 PMCID: PMC8713782 DOI: 10.1073/pnas.2101580118] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/21/2021] [Indexed: 02/05/2023] Open
Abstract
Sleep and wakefulness are not simple, homogenous all-or-none states but represent a spectrum of substates, distinguished by behavior, levels of arousal, and brain activity at the local and global levels. Until now, the role of the hypothalamic circuitry in sleep-wake control was studied primarily with respect to its contribution to rapid state transitions. In contrast, whether the hypothalamus modulates within-state dynamics (state "quality") and the functional significance thereof remains unexplored. Here, we show that photoactivation of inhibitory neurons in the lateral preoptic area (LPO) of the hypothalamus of adult male and female laboratory mice does not merely trigger awakening from sleep, but the resulting awake state is also characterized by an activated electroencephalogram (EEG) pattern, suggesting increased levels of arousal. This was associated with a faster build-up of sleep pressure, as reflected in higher EEG slow-wave activity (SWA) during subsequent sleep. In contrast, photoinhibition of inhibitory LPO neurons did not result in changes in vigilance states but was associated with persistently increased EEG SWA during spontaneous sleep. These findings suggest a role of the LPO in regulating arousal levels, which we propose as a key variable shaping the daily architecture of sleep-wake states.
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Affiliation(s)
- Tomoko Yamagata
- Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX1 3RE, United Kingdom
| | - Martin C Kahn
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - José Prius-Mengual
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - Elise Meijer
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - Merima Šabanović
- Department of Experimental Psychology, University of Oxford, Oxford OX2 6GG, United Kingdom
| | - Mathilde C C Guillaumin
- Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX1 3RE, United Kingdom
| | - Vincent van der Vinne
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - Yi-Ge Huang
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - Laura E McKillop
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - Aarti Jagannath
- Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX1 3RE, United Kingdom
| | - Stuart N Peirson
- Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX1 3RE, United Kingdom
| | - Edward O Mann
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - Russell G Foster
- Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX1 3RE, United Kingdom;
| | - Vladyslav V Vyazovskiy
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom;
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14
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Huang YG, Flaherty SJ, Pothecary CA, Foster RG, Peirson SN, Vyazovskiy VV. The relationship between fasting-induced torpor, sleep, and wakefulness in laboratory mice. Sleep 2021; 44:zsab093. [PMID: 33838033 PMCID: PMC8436144 DOI: 10.1093/sleep/zsab093] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 04/03/2021] [Indexed: 11/30/2022] Open
Abstract
STUDY OBJECTIVES Torpor is a regulated and reversible state of metabolic suppression used by many mammalian species to conserve energy. Whereas the relationship between torpor and sleep has been well-studied in seasonal hibernators, less is known about the effects of fasting-induced torpor on states of vigilance and brain activity in laboratory mice. METHODS Continuous monitoring of electroencephalogram (EEG), electromyogram (EMG), and surface body temperature was undertaken in adult, male C57BL/6 mice over consecutive days of scheduled restricted feeding. RESULTS All animals showed bouts of hypothermia that became progressively deeper and longer as fasting progressed. EEG and EMG were markedly affected by hypothermia, although the typical electrophysiological signatures of non-rapid eye movement (NREM) sleep, rapid eye movement (REM) sleep, and wakefulness enabled us to perform vigilance-state classification in all cases. Consistent with previous studies, hypothermic bouts were initiated from a state indistinguishable from NREM sleep, with EEG power decreasing gradually in parallel with decreasing surface body temperature. During deep hypothermia, REM sleep was largely abolished, and we observed shivering-associated intense bursts of muscle activity. CONCLUSIONS Our study highlights important similarities between EEG signatures of fasting-induced torpor in mice, daily torpor in Djungarian hamsters and hibernation in seasonally hibernating species. Future studies are necessary to clarify the effects on fasting-induced torpor on subsequent sleep.
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Affiliation(s)
- Yi-Ge Huang
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT,UK
| | - Sarah J Flaherty
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT,UK
| | - Carina A Pothecary
- Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neurosciences, Oxford Molecular Pathology Institute, Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE,UK
| | - Russell G Foster
- Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neurosciences, Oxford Molecular Pathology Institute, Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE,UK
| | - Stuart N Peirson
- Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neurosciences, Oxford Molecular Pathology Institute, Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE,UK
| | - Vladyslav V Vyazovskiy
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT,UK
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15
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Abstract
Understanding of the evolved biological function of sleep has advanced considerably in the past decade. However, no equivalent understanding of dreams has emerged. Contemporary neuroscientific theories often view dreams as epiphenomena, and many of the proposals for their biological function are contradicted by the phenomenology of dreams themselves. Now, the recent advent of deep neural networks (DNNs) has finally provided the novel conceptual framework within which to understand the evolved function of dreams. Notably, all DNNs face the issue of overfitting as they learn, which is when performance on one dataset increases but the network's performance fails to generalize (often measured by the divergence of performance on training versus testing datasets). This ubiquitous problem in DNNs is often solved by modelers via "noise injections" in the form of noisy or corrupted inputs. The goal of this paper is to argue that the brain faces a similar challenge of overfitting and that nightly dreams evolved to combat the brain's overfitting during its daily learning. That is, dreams are a biological mechanism for increasing generalizability via the creation of corrupted sensory inputs from stochastic activity across the hierarchy of neural structures. Sleep loss, specifically dream loss, leads to an overfitted brain that can still memorize and learn but fails to generalize appropriately. Herein this "overfitted brain hypothesis" is explicitly developed and then compared and contrasted with existing contemporary neuroscientific theories of dreams. Existing evidence for the hypothesis is surveyed within both neuroscience and deep learning, and a set of testable predictions is put forward that can be pursued both in vivo and in silico.
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Affiliation(s)
- Erik Hoel
- Allen Discovery Center, Tufts University, Medford, MA, USA
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16
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Milinski L, Fisher SP, Cui N, McKillop LE, Blanco-Duque C, Ang G, Yamagata T, Bannerman DM, Vyazovskiy VV. Waking experience modulates sleep need in mice. BMC Biol 2021; 19:65. [PMID: 33823872 PMCID: PMC8025572 DOI: 10.1186/s12915-021-00982-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 02/14/2021] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Homeostatic regulation of sleep is reflected in the maintenance of a daily balance between sleep and wakefulness. Although numerous internal and external factors can influence sleep, it is unclear whether and to what extent the process that keeps track of time spent awake is determined by the content of the waking experience. We hypothesised that alterations in environmental conditions may elicit different types of wakefulness, which will in turn influence both the capacity to sustain continuous wakefulness as well as the rates of accumulating sleep pressure. To address this, we compared the effects of repetitive behaviours such as voluntary wheel running or performing a simple touchscreen task, with wakefulness dominated by novel object exploration, on sleep timing and EEG slow-wave activity (SWA) during subsequent NREM sleep. RESULTS We find that voluntary wheel running is associated with higher wake EEG theta-frequency activity and results in longer wake episodes, as compared with exploratory behaviour; yet, it does not lead to higher levels of EEG SWA during subsequent NREM sleep in either the frontal or occipital derivation. Furthermore, engagement in a touchscreen task, motivated by food reward, results in lower SWA during subsequent NREM sleep in both derivations, as compared to exploratory wakefulness, even though the total duration of wakefulness is similar. CONCLUSION Overall, our study suggests that sleep-wake behaviour is highly flexible within an individual and that the homeostatic processes that keep track of time spent awake are sensitive to the nature of the waking experience. We therefore conclude that sleep dynamics are determined, to a large degree, by the interaction between the organism and the environment.
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Affiliation(s)
- Linus Milinski
- Department of Physiology, Anatomy and Genetics, University of Oxford/Sleep and Circadian Neuroscience Institute, Oxford, UK
| | - Simon P Fisher
- Department of Physiology, Anatomy and Genetics, University of Oxford/Sleep and Circadian Neuroscience Institute, Oxford, UK
| | - Nanyi Cui
- Department of Physiology, Anatomy and Genetics, University of Oxford/Sleep and Circadian Neuroscience Institute, Oxford, UK
| | - Laura E McKillop
- Department of Physiology, Anatomy and Genetics, University of Oxford/Sleep and Circadian Neuroscience Institute, Oxford, UK
| | - Cristina Blanco-Duque
- Department of Physiology, Anatomy and Genetics, University of Oxford/Sleep and Circadian Neuroscience Institute, Oxford, UK
| | - Gauri Ang
- Department of Experimental Psychology, University of Oxford, Oxford, UK
| | - Tomoko Yamagata
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - David M Bannerman
- Department of Experimental Psychology, University of Oxford, Oxford, UK
| | - Vladyslav V Vyazovskiy
- Department of Physiology, Anatomy and Genetics, University of Oxford/Sleep and Circadian Neuroscience Institute, Oxford, UK.
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17
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McKillop LE, Fisher SP, Milinski L, Krone LB, Vyazovskiy VV. Diazepam effects on local cortical neural activity during sleep in mice. Biochem Pharmacol 2021; 191:114515. [PMID: 33713641 PMCID: PMC8363939 DOI: 10.1016/j.bcp.2021.114515] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 03/03/2021] [Accepted: 03/04/2021] [Indexed: 12/20/2022]
Abstract
GABA-ergic neurotransmission plays a key role in sleep regulatory mechanisms and in brain oscillations during sleep. Benzodiazepines such as diazepam are known to induce sedation and promote sleep, however, EEG spectral power in slow frequencies is typically reduced after the administration of benzodiazepines or similar compounds. EEG slow waves arise from a synchronous alternation between periods of cortical network activity (ON) and silence (OFF), and represent a sensitive marker of preceding sleep-wake history. Yet it remains unclear how benzodiazepines act on cortical neural activity during sleep. To address this, we obtained chronic recordings of local field potentials and multiunit activity (MUA) from deep cortical layers of the primary motor cortex in freely behaving mice after diazepam injection. We found that the amplitude of individual LFP slow waves was significantly reduced after diazepam injection and was accompanied by a lower incidence and duration of the corresponding neuronal OFF periods. Further investigation suggested that this is due to a disruption in the synchronisation of cortical neurons. Our data suggest that the state of global sleep and local cortical synchrony can be dissociated, and that the brain state induced by benzodiazepines is qualitatively different from spontaneous physiological sleep.
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Affiliation(s)
- Laura E McKillop
- Department of Physiology, Anatomy and Genetics, University of Oxford/Sleep and Circadian Neuroscience Institute, United Kingdom
| | - Simon P Fisher
- Department of Physiology, Anatomy and Genetics, University of Oxford/Sleep and Circadian Neuroscience Institute, United Kingdom
| | - Linus Milinski
- Department of Physiology, Anatomy and Genetics, University of Oxford/Sleep and Circadian Neuroscience Institute, United Kingdom
| | - Lukas B Krone
- Department of Physiology, Anatomy and Genetics, University of Oxford/Sleep and Circadian Neuroscience Institute, United Kingdom
| | - Vladyslav V Vyazovskiy
- Department of Physiology, Anatomy and Genetics, University of Oxford/Sleep and Circadian Neuroscience Institute, United Kingdom.
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18
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Tuan LH, Tsao CY, Lee LJH, Lee LJ. Voluntary exercise ameliorates synaptic pruning deficits in sleep-deprived adolescent mice. Brain Behav Immun 2021; 93:96-110. [PMID: 33358980 DOI: 10.1016/j.bbi.2020.12.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 11/17/2020] [Accepted: 12/16/2020] [Indexed: 11/26/2022] Open
Abstract
Adolescence is a critical period for brain development and adequate sleep during this period is essential for physical function and mental health. Emerging evidence has detailed the neurological impacts of sleep insufficiency on adolescents, as was unveiled by our previous study, microglia, one of the crucial contributors to synaptic pruning, is functionally disrupted by lack of sleep. Here, we provided evidence featuring the protective effect and the underlying mechanisms of voluntary exercise (VE) on microglial functions in an adolescent 72 h sleep deprivation (SD) model. We identified that the aberrant hippocampal neuronal activity and impaired short-term memory performance in sleep-deprived mice were prevented by 11 days of VE. VE significantly normalized the SD-induced dendritic spine increment and maintained the microglial phagocytic ability in sleep-deprived mice. Moreover, we found that the amendment of the noradrenergic signal in the central nervous system may explain the preventative effects of VE on the abnormalities of microglial and neuronal functions caused by SD. These data suggested that VE may confer protection to the microglia-mediated synaptic pruning in the sleep-deprived adolescent brains. Therefore, physical exercise could be a beneficial health practice for the adolescents that copes the adverse influence of inevitable sleep insufficiency.
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Affiliation(s)
- Li-Heng Tuan
- Graduate Institute of Anatomy and Cell Biology, National Taiwan University, Taipei, Taiwan, ROC
| | - Chih-Yu Tsao
- Graduate Institute of Anatomy and Cell Biology, National Taiwan University, Taipei, Taiwan, ROC
| | - Lukas Jyuhn-Hsiarn Lee
- Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Miaoli, Taiwan, ROC
| | - Li-Jen Lee
- Graduate Institute of Anatomy and Cell Biology, National Taiwan University, Taipei, Taiwan, ROC; Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan, ROC; Institute of Brain and Mind Sciences, National Taiwan University, Taipei, Taiwan, ROC.
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19
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Thomas CW, Guillaumin MC, McKillop LE, Achermann P, Vyazovskiy VV. Global sleep homeostasis reflects temporally and spatially integrated local cortical neuronal activity. eLife 2020; 9:54148. [PMID: 32614324 PMCID: PMC7332296 DOI: 10.7554/elife.54148] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 06/19/2020] [Indexed: 12/16/2022] Open
Abstract
Sleep homeostasis manifests as a relative constancy of its daily amount and intensity. Theoretical descriptions define ‘Process S’, a variable with dynamics dependent on global sleep-wake history, and reflected in electroencephalogram (EEG) slow wave activity (SWA, 0.5–4 Hz) during sleep. The notion of sleep as a local, activity-dependent process suggests that activity history must be integrated to determine the dynamics of global Process S. Here, we developed novel mathematical models of Process S based on cortical activity recorded in freely behaving mice, describing local Process S as a function of the deviation of neuronal firing rates from a locally defined set-point, independent of global sleep-wake state. Averaging locally derived Processes S and their rate parameters yielded values resembling those obtained from EEG SWA and global vigilance states. We conclude that local Process S dynamics reflects neuronal activity integrated over time, and global Process S reflects local processes integrated over space.
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Affiliation(s)
- Christopher W Thomas
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Mathilde Cc Guillaumin
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Laura E McKillop
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Peter Achermann
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland.,The KEY Institute for Brain-Mind Research, Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital of Psychiatry, Zurich, Switzerland
| | - Vladyslav V Vyazovskiy
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
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20
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Das J, Singh R, Ladol S, Nayak SK, Sharma D. Fisetin prevents the aging-associated decline in relative spectral power of α, β and linked MUA in the cortex and behavioral alterations. Exp Gerontol 2020; 138:111006. [PMID: 32592831 DOI: 10.1016/j.exger.2020.111006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/15/2020] [Accepted: 06/15/2020] [Indexed: 12/22/2022]
Abstract
Mental health in old age is of great concern due to the increased incidence of neurological and psychiatric diseases. With age, probability of cognitive and behavioral deficits increase and the prognosis deteriorates. Although a few in vitro studies have reported that flavonoid fisetin is beneficial for healthy aging, its effect on deteriorating mental health with aging in vivo is very limited and poorly understood. The brain aging is physiologically characterized by electroencephalograph (EEG) wave frequency, power, and distribution. Brain oscillatory waves from neural tissue get altered by various sensory-cognitive inputs. Besides, the fast-wave α(8-12 Hz)- and β(12-28 Hz)-oscillations are associated with coordination and indeed deal with complex behavioral performances. Therefore, the effect of fisetin supplementation on age-associated EEG mean cortical spectral power in α- and β-oscillations, multi-unit activity (MUA) count were studied in vivo which was not addressed so far. Besides, age-associated cognitive and behavioral alterations were also studied. The relative spectral power of α and β declined along with the MUA count in aged rats compared to young. However, supplementing fisetin for four weeks has improved relative α-power, β-power, and MUA count in aged rats. Also, fisetin supplemented aged rats showed significantly improved cognitive and behavioral performances than aged controls. These findings demonstrated the relative cortical spectral power in α-, β-oscillations, and MUA count change in aged rats and that some of these changes and behavioral alterations may be partly as a result of oxidative stress, which was prevented significantly in fisetin supplemented aged rats. Thus, fisetin boosted mental health in the aged animals.
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Affiliation(s)
- Jharana Das
- Neurobiology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
| | - Rameshwar Singh
- Neurobiology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Stanzin Ladol
- Department of Zoology, Central University of Jammu, Jammu and Kashmir 181143, India.
| | - Sasmita Kumari Nayak
- Department of Instrumentation and Electronics, College of Engineering and Technology, Bhubaneswar 751003, India
| | - Deepak Sharma
- Neurobiology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
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21
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Northeast RC, Vyazovskiy VV, Bechtold DA. Eat, sleep, repeat: the role of the circadian system in balancing sleep-wake control with metabolic need. CURRENT OPINION IN PHYSIOLOGY 2020; 15:183-191. [PMID: 32617440 PMCID: PMC7323618 DOI: 10.1016/j.cophys.2020.02.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Feeding and sleep are behaviours fundamental to survival, and as such are subject to powerful homeostatic control. Of course, these are mutually exclusive behaviours, and therefore require coordinated temporal organisation to ensure that both energy demands and sleep need are met. Under optimal conditions, foraging/feeding and sleep can be simply partitioned to appropriate phases of the circadian cycle so that they are in suitable alignment with the external environment. However, under conditions of negative energy balance, increased foraging activity must be balanced against sleep requirements and energy conservation. In mammals and many other species, neural circuits that regulate sleep and energy balance are intimately and reciprocally linked. Here, we examine this circuitry, discuss how homeostatic regulation and temporal patterning of sleep are modulated by altered food availability, and describe the role of circadian system in adaptation to metabolic stress.
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Affiliation(s)
- Rebecca C Northeast
- Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
| | - Vladyslav V Vyazovskiy
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK
| | - David A Bechtold
- Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
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22
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Northeast RC, Huang Y, McKillop LE, Bechtold DA, Peirson SN, Piggins HD, Vyazovskiy VV. Sleep homeostasis during daytime food entrainment in mice. Sleep 2020; 42:5536856. [PMID: 31329251 PMCID: PMC6802571 DOI: 10.1093/sleep/zsz157] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 04/27/2019] [Indexed: 02/03/2023] Open
Abstract
Twenty-four hour rhythms of physiology and behavior are driven by the environment and an internal endogenous timing system. Daily restricted feeding (RF) in nocturnal rodents during their inactive phase initiates food anticipatory activity (FAA) and a reorganization of the typical 24-hour sleep-wake structure. Here, we investigate the effects of daytime feeding, where food access was restricted to 4 hours during the light period ZT4-8 (Zeitgeber time; ZT0 is lights on), on sleep-wake architecture and sleep homeostasis in mice. Following 10 days of RF, mice were returned to ad libitum feeding. To mimic the spontaneous wakefulness associated with FAA and daytime feeding, mice were then sleep deprived between ZT3-6. Although the amount of wake increased during FAA and subsequent feeding, total wake time over 24 hours remained stable as the loss of sleep in the light phase was compensated for by an increase in sleep in the dark phase. Interestingly, sleep that followed spontaneous wake episodes during the dark period and the extended period of wake associated with FAA, exhibited lower levels of slow-wave activity (SWA) when compared to baseline or after sleep deprivation, despite a similar duration of waking. This suggests an evolutionary mechanism of reducing sleep drive during negative energy balance to enable greater arousal for food-seeking behaviors. However, the total amount of sleep and SWA accumulated during the 24 hours was similar between baseline and RF. In summary, our study suggests that despite substantial changes in the daily distribution and quality of wake induced by RF, sleep homeostasis is maintained.
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Affiliation(s)
- Rebecca C Northeast
- Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford.,Faculty of Biology, Medicine, and Health, University of Manchester, Manchester
| | - Yige Huang
- Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford
| | - Laura E McKillop
- Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford
| | - David A Bechtold
- Faculty of Biology, Medicine, and Health, University of Manchester, Manchester
| | - Stuart N Peirson
- Sleep and Circadian Neuroscience Institute, Oxford Molecular Pathology Institute, Sir William Dunn School of Pathology, Oxford, United Kingdom
| | - Hugh D Piggins
- Faculty of Biology, Medicine, and Health, University of Manchester, Manchester
| | - Vladyslav V Vyazovskiy
- Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford.,Sleep and Circadian Neuroscience Institute, Oxford Molecular Pathology Institute, Sir William Dunn School of Pathology, Oxford, United Kingdom
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23
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Abstract
Sleep duration and lifespan vary greatly across Animalia. Human studies have demonstrated that ageing reduces the ability to obtain deep restorative sleep, and this may play a causative role in the development of age-related neurodegenerative disorders. Animal models are widely used in sleep and ageing studies. Importantly, in contrast to human studies, evidence from laboratory rodents suggests that sleep duration is increased with ageing, while evidence for reduced sleep intensity and consolidation is inconsistent. Here we discuss two possible explanations for these species differences. First, methodological differences between studies in humans and laboratory rodents may prevent straightforward comparison. Second, the role of ecological factors, which have a profound influence on both ageing and sleep, must be taken into account. We propose that the dynamics of sleep across the lifespan reflect both age-dependent changes in the neurobiological substrates of sleep as well as the capacity to adapt to the environment.
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24
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Timofeev I, Schoch SF, LeBourgeois MK, Huber R, Riedner BA, Kurth S. Spatio-temporal properties of sleep slow waves and implications for development. CURRENT OPINION IN PHYSIOLOGY 2020; 15:172-182. [PMID: 32455180 DOI: 10.1016/j.cophys.2020.01.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Objective sleep quality can be measured by electroencephalography (EEG), a non-invasive technique to quantify electrical activity generated by the brain. With EEG, sleep depth is measured by appearance and an increase in slow wave activity (scalp-SWA). EEG slow waves (scalp-SW) are the manifestation of underlying synchronous membrane potential transitions between silent (DOWN) and active (UP) states. This bistable periodic rhythm is defined as slow oscillation (SO). During its "silent state" cortical neurons are hyperpolarized and appear inactive, while during its "active state" cortical neurons are depolarized, fire spikes and exhibit continuous synaptic activity, excitatory and inhibitory. In adults, data from high-density EEG revealed that scalp-SW propagate across the cortical mantle in complex patterns. However, scalp-SW propagation undergoes modifications across development. We present novel data from children, indicating that scalp-SW originate centro-parietally, and emerge more frontally by adolescence. Based on the concept that SO and SW could actively modify neuronal connectivity, we discuss whether they fulfill a key purpose in brain development by actively conveying modifications of the maturing brain.
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Affiliation(s)
- Igor Timofeev
- CERVO Brain Research Centre, Québec, Canada.,Department of Psychiatry and Neuroscience, Université Laval, Québec, Canada
| | - Sarah F Schoch
- Department of Pulmonology, University Hospital Zurich, Zurich, CH
| | - Monique K LeBourgeois
- Sleep and Development Laboratory, Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
| | - Reto Huber
- Child Development Center, University Children's Hospital Zurich, Zurich, CH.,Department of Child and Adolescent Psychiatry and Psychotherapy, Psychiatric Hospital Zurich, Zurich, CH
| | - Brady A Riedner
- Wisconsin Institute for Sleep and Consciousness, Department of Psychiatry, University of Wisconsin-Madison, Madison, WI, USA
| | - Salome Kurth
- Department of Pulmonology, University Hospital Zurich, Zurich, CH.,Department of Psychology, University of Fribourg, Fribourg, CH
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25
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The Neuropeptide Galanin Is Required for Homeostatic Rebound Sleep following Increased Neuronal Activity. Neuron 2019; 104:370-384.e5. [PMID: 31537465 DOI: 10.1016/j.neuron.2019.08.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 06/04/2019] [Accepted: 08/03/2019] [Indexed: 01/19/2023]
Abstract
Sleep pressure increases during wake and dissipates during sleep, but the molecules and neurons that measure homeostatic sleep pressure remain poorly understood. We present a pharmacological assay in larval zebrafish that generates short-term increases in wakefulness followed by sustained rebound sleep after washout. The intensity of global neuronal activity during drug-induced wakefulness predicted the amount of subsequent rebound sleep. Whole-brain mapping with the neuronal activity marker phosphorylated extracellular signal-regulated kinase (pERK) identified preoptic Galanin (Galn)-expressing neurons as selectively active during rebound sleep, and the relative induction of galn transcripts was predictive of total rebound sleep time. Galn is required for sleep homeostasis, as galn mutants almost completely lacked rebound sleep following both pharmacologically induced neuronal activity and physical sleep deprivation. These results suggest that Galn plays a key role in responding to sleep pressure signals derived from neuronal activity and functions as an output arm of the vertebrate sleep homeostat.
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Shimaoka D, Harris KD, Carandini M. Effects of Arousal on Mouse Sensory Cortex Depend on Modality. Cell Rep 2019; 22:3160-3167. [PMID: 29562173 PMCID: PMC5883328 DOI: 10.1016/j.celrep.2018.02.092] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 12/01/2017] [Accepted: 02/22/2018] [Indexed: 11/29/2022] Open
Abstract
Changes in arousal modulate the activity of mouse sensory cortex, but studies in different mice and different sensory areas disagree on whether this modulation enhances or suppresses activity. We measured this modulation simultaneously in multiple cortical areas by imaging mice expressing voltage-sensitive fluorescent proteins (VSFP). VSFP imaging estimates local membrane potential across large portions of cortex. We used temporal filters to predict local potential from running speed or from pupil dilation, two measures of arousal. The filters provided good fits and revealed that the effects of arousal depend on modality. In the primary visual cortex (V1) and auditory cortex (Au), arousal caused depolarization followed by hyperpolarization. In the barrel cortex (S1b) and a secondary visual area (LM), it caused only hyperpolarization. In all areas, nonetheless, arousal reduced the phasic responses to trains of sensory stimuli. These results demonstrate diverse effects of arousal across sensory cortex but similar effects on sensory responses. Voltage-sensitive fluorescent proteins reveal effects of arousal across the cortex In auditory and primary visual areas, arousal depolarizes then hyperpolarizes In somatosensory and secondary visual areas, arousal only hyperpolarizes In all areas, arousal reduces phasic responses to trains of sensory stimuli
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Affiliation(s)
- Daisuke Shimaoka
- UCL Institute of Ophthalmology, University College London, Gower Street, London WC1E 6AE, UK.
| | - Kenneth D Harris
- UCL Institute of Neurology, University College London, Gower Street, London WC1E 6AE, UK; Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6AE, UK
| | - Matteo Carandini
- UCL Institute of Ophthalmology, University College London, Gower Street, London WC1E 6AE, UK
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Guillaumin MCC, McKillop LE, Cui N, Fisher SP, Foster RG, de Vos M, Peirson SN, Achermann P, Vyazovskiy VV. Cortical region-specific sleep homeostasis in mice: effects of time of day and waking experience. Sleep 2019; 41:4985519. [PMID: 29697841 PMCID: PMC6047413 DOI: 10.1093/sleep/zsy079] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 02/19/2018] [Indexed: 12/21/2022] Open
Abstract
Sleep–wake history, wake behaviors, lighting conditions, and circadian time influence sleep, but neither their relative contribution nor the underlying mechanisms are fully understood. The dynamics of electroencephalogram (EEG) slow-wave activity (SWA) during sleep can be described using the two-process model, whereby the parameters of homeostatic Process S are estimated using empirical EEG SWA (0.5–4 Hz) in nonrapid eye movement sleep (NREMS), and the 24 hr distribution of vigilance states. We hypothesized that the influence of extrinsic factors on sleep homeostasis, such as the time of day or wake behavior, would manifest in systematic deviations between empirical SWA and model predictions. To test this hypothesis, we performed parameter estimation and tested model predictions using NREMS SWA derived from continuous EEG recordings from the frontal and occipital cortex in mice. The animals showed prolonged wake periods, followed by consolidated sleep, both during the dark and light phases, and wakefulness primarily consisted of voluntary wheel running, learning a new motor skill or novel object exploration. Simulated SWA matched empirical levels well across conditions, and neither waking experience nor time of day had a significant influence on the fit between data and simulation. However, we consistently observed that Process S declined during sleep significantly faster in the frontal than in the occipital area of the neocortex. The striking resilience of the model to specific wake behaviors, lighting conditions, and time of day suggests that intrinsic factors underpinning the dynamics of Process S are robust to extrinsic influences, despite their major role in shaping the overall amount and distribution of vigilance states across 24 hr.
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Affiliation(s)
| | - Laura E McKillop
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Nanyi Cui
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Simon P Fisher
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Russell G Foster
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Maarten de Vos
- Department of Engineering Science, University of Oxford, Headington, United Kingdom
| | - Stuart N Peirson
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Peter Achermann
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Vladyslav V Vyazovskiy
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
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28
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Panagiotou M, Meijer M, Meijer JH, Deboer T. Effects of chronic caffeine consumption on sleep and the sleep electroencephalogram in mice. J Psychopharmacol 2019; 33:122-131. [PMID: 30354930 PMCID: PMC6343423 DOI: 10.1177/0269881118806300] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND Caffeine is one of the most widely consumed psychostimulants, and it impacts sleep and circadian physiology. AIM Caffeine is generally used chronically on a daily basis. Therefore, in the current study, we investigated the chronic effect of caffeine on sleep in mice. METHODS We recorded the electroencephalogram and electromyogram on a control day, on the first day of caffeine consumption (acute), and following two weeks of continuous caffeine consumption (chronic). In the latter condition, a period of six-hour sleep deprivation was conducted during the light period. Control mice, which received normal drinking water, were also recorded and sleep deprived. RESULTS We found that caffeine induced differential effects following acute and chronic consumption. Over 24 h, waking increased following acute caffeine whereas no changes were found in the chronic condition. The daily amplitude of sleep-wake states increased in both acute and chronic conditions, with the highest amplitude in the chronic condition, showing an increase in sleep during the light and an increase in waking during the dark. Furthermore, electroencephalogram slow-wave-activity in non-rapid eye-movement sleep was increased, compared with both control conditions, during the first half of the light period in the chronic condition. It was particularly challenging to keep the animals awake during the sleep deprivation period under chronic caffeine. CONCLUSIONS Together the data suggest an increased sleep pressure under chronic caffeine. In contrast to the traditional conception on the impact on sleep, chronic caffeine intake seems to increase the daily sleep-wake cycle amplitude and increase sleep pressure in mice.
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Affiliation(s)
- Maria Panagiotou
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Mandy Meijer
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Johanna H Meijer
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Tom Deboer
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
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29
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30
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Effects of Aging on Cortical Neural Dynamics and Local Sleep Homeostasis in Mice. J Neurosci 2018; 38:3911-3928. [PMID: 29581380 PMCID: PMC5907054 DOI: 10.1523/jneurosci.2513-17.2018] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 02/21/2018] [Accepted: 02/22/2018] [Indexed: 01/13/2023] Open
Abstract
Healthy aging is associated with marked effects on sleep, including its daily amount and architecture, as well as the specific EEG oscillations. Neither the neurophysiological underpinnings nor the biological significance of these changes are understood, and crucially the question remains whether aging is associated with reduced sleep need or a diminished capacity to generate sufficient sleep. Here we tested the hypothesis that aging may affect local cortical networks, disrupting the capacity to generate and sustain sleep oscillations, and with it the local homeostatic response to sleep loss. We performed chronic recordings of cortical neural activity and local field potentials from the motor cortex in young and older male C57BL/6J mice, during spontaneous waking and sleep, as well as during sleep after sleep deprivation. In older animals, we observed an increase in the incidence of non-rapid eye movement sleep local field potential slow waves and their associated neuronal silent (OFF) periods, whereas the overall pattern of state-dependent cortical neuronal firing was generally similar between ages. Furthermore, we observed that the response to sleep deprivation at the level of local cortical network activity was not affected by aging. Our data thus suggest that the local cortical neural dynamics and local sleep homeostatic mechanisms, at least in the motor cortex, are not impaired during healthy senescence in mice. This indicates that powerful protective or compensatory mechanisms may exist to maintain neuronal function stable across the life span, counteracting global changes in sleep amount and architecture. SIGNIFICANCE STATEMENT The biological significance of age-dependent changes in sleep is unknown but may reflect either a diminished sleep need or a reduced capacity to generate deep sleep stages. As aging has been linked to profound disruptions in cortical sleep oscillations and because sleep need is reflected in specific patterns of cortical activity, we performed chronic electrophysiological recordings of cortical neural activity during waking, sleep, and after sleep deprivation from young and older mice. We found that all main hallmarks of cortical activity during spontaneous sleep and recovery sleep after sleep deprivation were largely intact in older mice, suggesting that the well-described age-related changes in global sleep are unlikely to arise from a disruption of local network dynamics within the neocortex.
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McKillop LE, Vyazovskiy VV. Sleep- and Wake-Like States in Small Networks In Vivo and In Vitro. Handb Exp Pharmacol 2018; 253:97-121. [PMID: 30443784 DOI: 10.1007/164_2018_174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Wakefulness and sleep are highly complex and heterogeneous processes, involving multiple neurotransmitter systems and a sophisticated interplay between global and local networks of neurons and non-neuronal cells. Macroscopic approaches applied at the level of the whole organism, view sleep as a global behaviour and allow for investigation into aspects such as the effects of insufficient or disrupted sleep on cognitive function, metabolism, thermoregulation and sensory processing. While significant progress has been achieved using such large-scale approaches, the inherent complexity of sleep-wake regulation has necessitated the development of methods which tackle specific aspects of sleep in isolation. One way this may be achieved is by investigating specific cellular or molecular phenomena in the whole organism in situ, either during spontaneous or induced sleep-wake states. This approach has greatly advanced our knowledge about the electrophysiology and pharmacology of ion channels, specific receptors, intracellular pathways and the small networks implicated in the control and regulation of the sleep-wake cycle. Importantly though, there are a variety of external and internal factors that influence global behavioural states which are difficult to control for using these approaches. For this reason, over the last few decades, ex vivo experimental models have become increasingly popular and have greatly advanced our understanding of many fundamental aspects of sleep, including the neuroanatomy and neurochemistry of sleep states, sleep regulation, the origin and dynamics of specific sleep oscillations, network homeostasis as well as the functional roles of sleep. This chapter will focus on the use of small neuronal networks as experimental models and will highlight the most significant and novel insights these approaches have provided.
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Affiliation(s)
- Laura E McKillop
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
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32
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Miyamoto D, Hirai D, Murayama M. The Roles of Cortical Slow Waves in Synaptic Plasticity and Memory Consolidation. Front Neural Circuits 2017; 11:92. [PMID: 29213231 PMCID: PMC5703076 DOI: 10.3389/fncir.2017.00092] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Accepted: 11/08/2017] [Indexed: 11/19/2022] Open
Abstract
Sleep plays important roles in sensory and motor memory consolidation. Sleep oscillations, reflecting neural population activity, involve the reactivation of learning-related neurons and regulate synaptic strength and, thereby affect memory consolidation. Among sleep oscillations, slow waves (0.5–4 Hz) are closely associated with memory consolidation. For example, slow-wave power is regulated in an experience-dependent manner and correlates with acquired memory. Furthermore, manipulating slow waves can enhance or impair memory consolidation. During slow wave sleep, inter-areal interactions between the cortex and hippocampus (HC) have been proposed to consolidate declarative memory; however, interactions for non-declarative (HC-independent) memory remain largely uninvestigated. We recently showed that the directional influence in a slow-wave range through a top-down cortical long-range circuit is involved in the consolidation of non-declarative memory. At the synaptic level, the average cortical synaptic strength is known to be potentiated during wakefulness and depressed during sleep. Moreover, learning causes plasticity in a subset of synapses, allocating memory to them. Sleep may help to differentiate synaptic strength between allocated and non-allocated synapses (i.e., improving the signal-to-noise ratio, which may facilitate memory consolidation). Herein, we offer perspectives on inter-areal interactions and synaptic plasticity for memory consolidation during sleep.
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Affiliation(s)
- Daisuke Miyamoto
- Laboratory for Behavioral Neurophysiology, RIKEN Brain Science Institute, Wako, Japan.,Japan Society for the Promotion of Science (JSPS), Tokyo, Japan
| | - Daichi Hirai
- Laboratory for Behavioral Neurophysiology, RIKEN Brain Science Institute, Wako, Japan
| | - Masanori Murayama
- Laboratory for Behavioral Neurophysiology, RIKEN Brain Science Institute, Wako, Japan
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33
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Abstract
The motor cortex is a large frontal structure in the cerebral cortex of eutherian mammals. A vast array of evidence implicates the motor cortex in the volitional control of motor output, but how does the motor cortex exert this 'control'? Historically, ideas regarding motor cortex function have been shaped by the discovery of cortical 'motor maps' - that is, ordered representations of stimulation-evoked movements in anaesthetized animals. Volitional control, however, entails the initiation of movements and the ability to suppress undesired movements. In this article, we highlight classic and recent findings that emphasize that motor cortex neurons have a role in both processes.
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34
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Holst SC, Sousek A, Hefti K, Saberi-Moghadam S, Buck A, Ametamey SM, Scheidegger M, Franken P, Henning A, Seifritz E, Tafti M, Landolt HP. Cerebral mGluR5 availability contributes to elevated sleep need and behavioral adjustment after sleep deprivation. eLife 2017; 6:28751. [PMID: 28980941 PMCID: PMC5644949 DOI: 10.7554/elife.28751] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 10/04/2017] [Indexed: 12/16/2022] Open
Abstract
Increased sleep time and intensity quantified as low-frequency brain electrical activity after sleep loss demonstrate that sleep need is homeostatically regulated, yet the underlying molecular mechanisms remain elusive. We here demonstrate that metabotropic glutamate receptors of subtype 5 (mGluR5) contribute to the molecular machinery governing sleep-wake homeostasis. Using positron emission tomography, magnetic resonance spectroscopy, and electroencephalography in humans, we find that increased mGluR5 availability after sleep loss tightly correlates with behavioral and electroencephalographic biomarkers of elevated sleep need. These changes are associated with altered cortical myo-inositol and glycine levels, suggesting sleep loss-induced modifications downstream of mGluR5 signaling. Knock-out mice without functional mGluR5 exhibit severe dysregulation of sleep-wake homeostasis, including lack of recovery sleep and impaired behavioral adjustment to a novel task after sleep deprivation. The data suggest that mGluR5 contribute to the brain's coping mechanisms with sleep deprivation and point to a novel target to improve disturbed wakefulness and sleep.
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Affiliation(s)
- Sebastian C Holst
- Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland.,CRPP Sleep and Health, Zürich Center for Interdisciplinary Sleep Research, University of Zürich, Zürich, Switzerland
| | - Alexandra Sousek
- Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland.,Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Katharina Hefti
- Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland
| | | | - Alfred Buck
- Division of Nuclear Medicine, University Hospital Zürich, Zürich, Switzerland
| | - Simon M Ametamey
- Center for Radiopharmaceutical Sciences of ETH, Zürich, Switzerland.,Paul Scherrer Institut, Zürich, Switzerland.,University Hospital of Zürich, Zürich, Switzerland
| | - Milan Scheidegger
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zürich, Zürich, Switzerland.,Institute for Biomedical Engineering, University of Zürich and ETH Zürich, Zürich, Switzerland
| | - Paul Franken
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Anke Henning
- Center for Radiopharmaceutical Sciences of ETH, Zürich, Switzerland.,Paul Scherrer Institut, Zürich, Switzerland.,University Hospital of Zürich, Zürich, Switzerland
| | - Erich Seifritz
- CRPP Sleep and Health, Zürich Center for Interdisciplinary Sleep Research, University of Zürich, Zürich, Switzerland.,Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zürich, Zürich, Switzerland
| | - Mehdi Tafti
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland.,Department of Physiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Hans-Peter Landolt
- Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland.,CRPP Sleep and Health, Zürich Center for Interdisciplinary Sleep Research, University of Zürich, Zürich, Switzerland
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35
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The Interplay between Long- and Short-Range Temporal Correlations Shapes Cortex Dynamics across Vigilance States. J Neurosci 2017; 37:10114-10124. [PMID: 28947577 DOI: 10.1523/jneurosci.0448-17.2017] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 08/07/2017] [Indexed: 02/06/2023] Open
Abstract
Increasing evidence suggests that cortical dynamics during wake exhibits long-range temporal correlations suitable to integrate inputs over extended periods of time to increase the signal-to-noise ratio in decision making and working memory tasks. Accordingly, sleep has been suggested as a state characterized by a breakdown of long-range correlations. However, detailed measurements of neuronal timescales that support this view have so far been lacking. Here, we show that the cortical timescales measured at the individual neuron level in freely behaving male rats change as a function of vigilance state and time awake. Although quiet wake and rapid eye movement (REM) sleep are characterized by similar, long timescales, these long timescales are abrogated in non-REM sleep. We observe that cortex dynamics exhibits rapid transitions between long-timescale states and sleep-like states governed by short timescales even during wake. This becomes particularly evident during sleep deprivation, when the interplay between these states can lead to an increasing disruption of long timescales that are restored after sleep. Experiments and modeling identify the intrusion of neuronal offline periods as a mechanism that disrupts the long timescales arising from reverberating cortical network activity. Our results provide novel mechanistic and functional links among behavioral manifestations of sleep, wake, and sleep deprivation and specific measurable changes in the network dynamics relevant for characterizing the brain's changing information-processing capabilities. They suggest a network-level function of sleep to reorganize cortical networks toward states governed by long timescales to ensure efficient information integration for the time awake.SIGNIFICANCE STATEMENT Lack of sleep deteriorates several key cognitive functions, yet the neuronal underpinnings of these deficits have remained elusive. Cognitive capabilities are generally believed to benefit from a neural circuit's ability to reliably integrate information. Persistent network activity characterized by long timescales may provide the basis for this integration in cortex. Here, we show that long-range temporal correlations indicated by slowly decaying autocorrelation functions in neuronal activity are dependent on vigilance states. Although wake and rapid eye movement (REM) sleep exhibit long timescales, these long-range correlations break down during non-REM sleep. Our findings thus suggest two distinct states in terms of timescale dynamics. During extended wake, the rapid switching to sleep-like states with short timescales can lead to an overall decline in cortical timescales.
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36
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Fattinger S, Kurth S, Ringli M, Jenni OG, Huber R. Theta waves in children's waking electroencephalogram resemble local aspects of sleep during wakefulness. Sci Rep 2017; 7:11187. [PMID: 28894254 PMCID: PMC5593855 DOI: 10.1038/s41598-017-11577-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 08/25/2017] [Indexed: 02/04/2023] Open
Abstract
Vyazovskiy and colleagues found in rats’ multi-unit recordings brief periods of silence (off-states) in local populations of cortical neurons during wakefulness which closely resembled the characteristic off-states during sleep. These off-states became more global and frequent with increasing sleep pressure and were associated with the well-known increase of theta activity under sleep deprivation in the surface EEG. Moreover, the occurrence of such off-states was related to impaired performance. While these animal experiments were based on intracranial recordings, we aimed to explore whether the human surface EEG may also provide evidence for such a local sleep-like intrusion during wakefulness. Thus, we analysed high-density wake EEG recordings during an auditory attention task in the morning and evening in 12 children. We found that, theta waves became more widespread in the evening and the occurrence of widespread theta waves was associated with slower reaction times in the attention task. These results indicate that widespread theta events measured on the scalp might be markers of local sleep in humans. Moreover, such markers of local sleep, seem to be related to the well described performance decline under high sleep pressure.
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Affiliation(s)
- Sara Fattinger
- Child Development Center, University Children's Hospital Zurich, Zurich, Switzerland.,Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, Zurich, Switzerland
| | - Salome Kurth
- Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, Zurich, Switzerland.,Pulmonary Clinic, Division of Pulmonology, University Hospital Zurich, Zurich, Switzerland
| | - Maya Ringli
- Child Development Center, University Children's Hospital Zurich, Zurich, Switzerland.,Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, Zurich, Switzerland
| | - Oskar G Jenni
- Child Development Center, University Children's Hospital Zurich, Zurich, Switzerland.,Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, Zurich, Switzerland
| | - Reto Huber
- Child Development Center, University Children's Hospital Zurich, Zurich, Switzerland. .,Neuroscience Center Zurich, Zurich, Switzerland. .,Department of Child and Adolescent Psychiatry and Psychotherapy, Psychiatric Hospital, University of Zurich, Zurich, Switzerland.
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Hypocretin (orexin) is critical in sustaining theta/gamma-rich waking behaviors that drive sleep need. Proc Natl Acad Sci U S A 2017. [PMID: 28630298 DOI: 10.1073/pnas.1700983114] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Hcrt gene inactivation in mice leads to behavioral state instability, abnormal transitions to paradoxical sleep, and cataplexy, hallmarks of narcolepsy. Sleep homeostasis is, however, considered unimpaired in patients and narcoleptic mice. We find that whereas Hcrtko/ko mice respond to 6-h sleep deprivation (SD) with a slow-wave sleep (SWS) EEG δ (1.0 to 4.0 Hz) power rebound like WT littermates, spontaneous waking fails to induce a δ power reflecting prior waking duration. This correlates with impaired θ (6.0 to 9.5 Hz) and fast-γ (55 to 80 Hz) activity in prior waking. We algorithmically identify a theta-dominated wakefulness (TDW) substate underlying motivated behaviors and typically preceding cataplexy in Hcrtko/ko mice. Hcrtko/ko mice fully implement TDW when waking is enforced, but spontaneous TDW episode duration is greatly reduced. A reformulation of the classic sleep homeostasis model, where homeostatic pressure rises exclusively in TDW rather than all waking, predicts δ power dynamics both in Hcrtko/ko and WT mouse baseline and recovery SWS. The low homeostatic impact of Hcrtko/ko mouse spontaneous waking correlates with decreased cortical expression of neuronal activity-related genes (notably Bdnf, Egr1/Zif268, and Per2). Thus, spontaneous TDW stability relies on Hcrt to sustain θ/fast-γ network activity and associated plasticity, whereas other arousal circuits sustain TDW during SD. We propose that TDW identifies a discrete global brain activity mode that is regulated by context-dependent neuromodulators and acts as a major driver of sleep homeostasis. Hcrt loss in Hcrtko/ko mice causes impaired TDW maintenance in baseline wake and blunted δ power in SWS, reproducing, respectively, narcolepsy excessive daytime sleepiness and poor sleep quality.
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38
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Vyazovskiy VV, Walton ME, Peirson SN, Bannerman DM. Sleep homeostasis, habits and habituation. Curr Opin Neurobiol 2017; 44:202-211. [PMID: 28575718 DOI: 10.1016/j.conb.2017.05.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 04/06/2017] [Accepted: 05/01/2017] [Indexed: 02/08/2023]
Abstract
The importance of sleep for behavioural performance during waking is long-established, but the underlying reasons and mechanisms remain elusive. Waking and sleep are associated with changes in the levels of GluA1 AMPAR subunit in synaptic membranes, while studies using genetically-modified mice have identified an important role for GluA1-dependent synaptic plasticity in a non-associative form of memory that underlies short-term habituation to recently experienced stimuli. Here we posit that sleep may play a role in dishabituation, which restores attentional capacity and maximises the readiness of the animal for learning and goal-directed behaviour during subsequent wakefulness. Furthermore we suggest that sleep disturbance may fundamentally change the nature of behaviour, making it more model-free and habitual as a result of reduced attentional capacity.
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Affiliation(s)
- Vladyslav V Vyazovskiy
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, United Kingdom; Sleep and Circadian Neuroscience Institute, Oxford Molecular Pathology Institute, Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, United Kingdom.
| | - Mark E Walton
- Department of Experimental Psychology, University of Oxford,South Parks Road, Oxford OX1 3UD, United Kingdom
| | - Stuart N Peirson
- Sleep and Circadian Neuroscience Institute, Oxford Molecular Pathology Institute, Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, United Kingdom
| | - David M Bannerman
- Sleep and Circadian Neuroscience Institute, Oxford Molecular Pathology Institute, Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, United Kingdom; Department of Experimental Psychology, University of Oxford,South Parks Road, Oxford OX1 3UD, United Kingdom
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39
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Timofeev I, Chauvette S. Sleep slow oscillation and plasticity. Curr Opin Neurobiol 2017; 44:116-126. [PMID: 28453998 DOI: 10.1016/j.conb.2017.03.019] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 03/31/2017] [Indexed: 11/25/2022]
Abstract
It is well documented that sleep contributes to memory consolidation and it is also accepted that long-term synaptic plasticity plays a critical role in memory formation. The mechanisms of this sleep-dependent memory formation are unclear. Two main hypotheses are proposed. According to the first one, synapses are potentiated during wake; and during sleep they are scaled back to become available for the learning tasks in the next day. The other hypothesis is that sleep slow oscillations potentiate synapses that were depressed due to persistent activities during the previous day and that potentiation provides physiological basis for memory consolidation. The objective of this review is to group information on whether cortical synapses are up-scaled or down-scaled during sleep. We conclude that the majority of cortical synapses are up-regulated by sleep slow oscillation.
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Affiliation(s)
- Igor Timofeev
- Department of Psychiatry and Neuroscience, Université Laval Québec, QC G1V 0A6, Canada; Centre de recherche de l'Institut universitaire en santé mentale de Québec (CRIUSMQ), 2601, de la Canardière Québec, QC G1J 2G3, Canada.
| | - Sylvain Chauvette
- Centre de recherche de l'Institut universitaire en santé mentale de Québec (CRIUSMQ), 2601, de la Canardière Québec, QC G1J 2G3, Canada
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Cirelli C. Sleep, synaptic homeostasis and neuronal firing rates. Curr Opin Neurobiol 2017; 44:72-79. [PMID: 28399462 DOI: 10.1016/j.conb.2017.03.016] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 03/01/2017] [Accepted: 03/12/2017] [Indexed: 12/27/2022]
Abstract
The synaptic homeostasis hypothesis (SHY) states that wake brings about a net overall increase in synaptic strength in many brain circuits that needs to be renormalized by sleep. I will review recent studies that were either specifically designed to test SHY or were interpreted accordingly, including several experiments that focused on changes in neuronal firing rates. I will emphasize that central to SHY is the idea that what is being regulated across the sleep/wake cycle is synaptic strength, not firing rate, and firing rate taken in isolation is not necessarily an adequate proxy for synaptic strength.
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Affiliation(s)
- Chiara Cirelli
- Department of Psychiatry, University of Wisconsin, Madison, WI 53719, USA.
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