401
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Bersagliere A, Pascual-Marqui RD, Tarokh L, Achermann P. Mapping Slow Waves by EEG Topography and Source Localization: Effects of Sleep Deprivation. Brain Topogr 2017; 31:257-269. [PMID: 28983703 DOI: 10.1007/s10548-017-0595-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 09/18/2017] [Indexed: 11/26/2022]
Abstract
Slow waves are a salient feature of the electroencephalogram (EEG) during non-rapid eye movement (non-REM) sleep. The aim of this study was to assess the topography of EEG power and the activation of brain structures during slow wave sleep under normal conditions and after sleep deprivation. Sleep EEG recordings during baseline and recovery sleep after 40 h of sustained wakefulness were analyzed (eight healthy young men, 27 channel EEG). Power maps were computed for the first non-REM sleep episode (where sleep pressure is highest) in baseline and recovery sleep, at frequencies between 0.5 and 2 Hz. Power maps had a frontal predominance at all frequencies between 0.5 and 2 Hz. An additional occipital focus of activity was observed below 1 Hz. Power maps ≤ 1 Hz were not affected by sleep deprivation, whereas an increase in power was observed in the maps ≥ 1.25 Hz. Based on the response to sleep deprivation, low-delta (0.5-1 Hz) and mid-delta activity (1.25-2 Hz) were dissociated. Electrical sources within the cortex of low- and mid-delta activity were estimated using eLORETA. Source localization revealed a predominantly frontal distribution of activity for low-delta and mid-delta activity. Sleep deprivation resulted in an increase in source strength only for mid-delta activity, mainly in parietal and frontal regions. Low-delta activity dominated in occipital and temporal regions and mid-delta activity in limbic and frontal regions independent of the level of sleep pressure. Both, power maps and electrical sources exhibited trait-like aspects.
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Affiliation(s)
- Alessia Bersagliere
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstr. 190, 8057, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Roberto D Pascual-Marqui
- The KEY Institute for Brain-Mind Research, Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital of Psychiatry, Zurich, Switzerland
| | - Leila Tarokh
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstr. 190, 8057, Zurich, Switzerland
- University Hospital of Child and Adolescent Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland
| | - Peter Achermann
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstr. 190, 8057, Zurich, Switzerland.
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland.
- The KEY Institute for Brain-Mind Research, Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital of Psychiatry, Zurich, Switzerland.
- Zurich Center for Interdisciplinary Sleep Research, University of Zurich, Zurich, Switzerland.
- Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.
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402
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Abstract
Introduction EEG oscillations known as sleep spindles have been linked with various aspects of cognition, but the specific functions they signal remain controversial. Two types of EEG sleep spindles have been distinguished: slow spindles at 11-13.5 Hz and fast spindles at 13.5-16 Hz. Slow spindles exhibit a frontal scalp topography, whereas fast spindles exhibit a posterior scalp topography and have been preferentially linked with memory consolidation during sleep. To advance understanding beyond that provided from correlative studies of spindles, we aimed to develop a new method to systematically manipulate spindles. Aims and Methods We presented repeating bursts of oscillating white noise to people during a 90-min afternoon nap. During stage 2 and slow-wave sleep, oscillations were embedded within contiguous 10-s stimulation intervals, each comprising 2 s of white noise amplitude modulated at 12 Hz (targeting slow spindles), 15 Hz (targeting fast spindles), or 50 Hz followed by 8 s of constant white noise. Results During oscillating stimulation compared to constant stimulation, parietal EEG recordings showed more slow spindles in the 12-Hz condition, more fast spindles in the 15-Hz condition, and no change in the 50-Hz control condition. These effects were topographically selective, and were absent in frontopolar EEG recordings, where slow spindle density was highest. Spindles during stimulation were similar to spontaneous spindles in standard physiological features, including duration and scalp distribution. Conclusions These results define a new method to selectively and noninvasively manipulate spindles through acoustic resonance, while also providing new evidence for functional distinctions between the 2 types of EEG spindles.
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Affiliation(s)
- James W Antony
- Interdepartmental Neuroscience Program, Northwestern University, Evanston, IL 60208.,Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544
| | - Ken A Paller
- Interdepartmental Neuroscience Program, Northwestern University, Evanston, IL 60208.,Department of Psychology, Northwestern University, Evanston, IL 60208
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403
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Berger C, Kühne D, Scheper V, Kral A. Congenital deafness affects deep layers in primary and secondary auditory cortex. J Comp Neurol 2017; 525. [PMID: 28643417 PMCID: PMC5599951 DOI: 10.1002/cne.24267] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Congenital deafness leads to functional deficits in the auditory cortex for which early cochlear implantation can effectively compensate. Most of these deficits have been demonstrated functionally. Furthermore, the majority of previous studies on deafness have involved the primary auditory cortex; knowledge of higher-order areas is limited to effects of cross-modal reorganization. In this study, we compared the cortical cytoarchitecture of four cortical areas in adult hearing and congenitally deaf cats (CDCs): the primary auditory field A1, two secondary auditory fields, namely the dorsal zone and second auditory field (A2); and a reference visual association field (area 7) in the same section stained either using Nissl or SMI-32 antibodies. The general cytoarchitectonic pattern and the area-specific characteristics in the auditory cortex remained unchanged in animals with congenital deafness. Whereas area 7 did not differ between the groups investigated, all auditory fields were slightly thinner in CDCs, this being caused by reduced thickness of layers IV-VI. The study documents that, while the cytoarchitectonic patterns are in general independent of sensory experience, reduced layer thickness is observed in both primary and higher-order auditory fields in layer IV and infragranular layers. The study demonstrates differences in effects of congenital deafness between supragranular and other cortical layers, but similar dystrophic effects in all investigated auditory fields.
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Affiliation(s)
- Christoph Berger
- Institute of AudioNeuroTechnology & Department of Experimental OtologyENT Clinics, School of Medicine, Hannover Medical UniversityHannoverGermany
| | - Daniela Kühne
- Institute of AudioNeuroTechnology & Department of Experimental OtologyENT Clinics, School of Medicine, Hannover Medical UniversityHannoverGermany
| | - Verena Scheper
- Institute of AudioNeuroTechnology & Department of Experimental OtologyENT Clinics, School of Medicine, Hannover Medical UniversityHannoverGermany
| | - Andrej Kral
- Institute of AudioNeuroTechnology & Department of Experimental OtologyENT Clinics, School of Medicine, Hannover Medical UniversityHannoverGermany
- School of Behavioral and Brain SciencesThe University of TexasDallasUSA
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404
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Song I, Orosz I, Chervoneva I, Waldman ZJ, Fried I, Wu C, Sharan A, Salamon N, Gorniak R, Dewar S, Bragin A, Engel J, Sperling MR, Staba R, Weiss SA. Bimodal coupling of ripples and slower oscillations during sleep in patients with focal epilepsy. Epilepsia 2017; 58:1972-1984. [PMID: 28948998 DOI: 10.1111/epi.13912] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/29/2017] [Indexed: 12/26/2022]
Abstract
OBJECTIVE Differentiating pathologic and physiologic high-frequency oscillations (HFOs) is challenging. In patients with focal epilepsy, HFOs occur during the transitional periods between the up and down state of slow waves. The preferred phase angles of this form of phase-event amplitude coupling are bimodally distributed, and the ripples (80-150 Hz) that occur during the up-down transition more often occur in the seizure-onset zone (SOZ). We investigated if bimodal ripple coupling was also evident for faster sleep oscillations, and could identify the SOZ. METHODS Using an automated ripple detector, we identified ripple events in 40-60 min intracranial electroencephalography (iEEG) recordings from 23 patients with medically refractory mesial temporal lobe or neocortical epilepsy. The detector quantified epochs of sleep oscillations and computed instantaneous phase. We utilized a ripple phasor transform, ripple-triggered averaging, and circular statistics to investigate phase event-amplitude coupling. RESULTS We found that at some individual recording sites, ripple event amplitude was coupled with the sleep oscillatory phase and the preferred phase angles exhibited two distinct clusters (p < 0.05). The distribution of the pooled mean preferred phase angle, defined by combining the means from each cluster at each individual recording site, also exhibited two distinct clusters (p < 0.05). Based on the range of preferred phase angles defined by these two clusters, we partitioned each ripple event at each recording site into two groups: depth iEEG peak-trough and trough-peak. The mean ripple rates of the two groups in the SOZ and non-SOZ (NSOZ) were compared. We found that in the frontal (spindle, p = 0.009; theta, p = 0.006, slow, p = 0.004) and parietal lobe (theta, p = 0.007, delta, p = 0.002, slow, p = 0.001) the SOZ incidence rate for the ripples occurring during the trough-peak transition was significantly increased. SIGNIFICANCE Phase-event amplitude coupling between ripples and sleep oscillations may be useful to distinguish pathologic and physiologic events in patients with frontal and parietal SOZ.
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Affiliation(s)
- Inkyung Song
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, U.S.A
| | - Iren Orosz
- Department of Radiology, David Geffen School of Medicine at UCLA, Los Angeles, California, U.S.A
| | - Inna Chervoneva
- Department of Pharmacology & Experimental Therapeutics, Thomas Jefferson University, Philadelphia, Pennsylvania, U.S.A
| | - Zachary J Waldman
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, U.S.A
| | - Itzhak Fried
- Department of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, California, U.S.A
| | - Chengyuan Wu
- Department of Neurological Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania, U.S.A
| | - Ashwini Sharan
- Department of Neurological Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania, U.S.A
| | - Noriko Salamon
- Department of Radiology, David Geffen School of Medicine at UCLA, Los Angeles, California, U.S.A
| | - Richard Gorniak
- Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania, U.S.A
| | - Sandra Dewar
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California, U.S.A
| | - Anatol Bragin
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California, U.S.A
| | - Jerome Engel
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California, U.S.A.,Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California, U.S.A.,Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, California, U.S.A.,Brain Research Institute, David Geffen School of Medicine at UCLA, Los Angeles, California, U.S.A
| | - Michael R Sperling
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, U.S.A
| | - Richard Staba
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California, U.S.A
| | - Shennan A Weiss
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, U.S.A
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405
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Ju YES, Ooms SJ, Sutphen C, Macauley SL, Zangrilli MA, Jerome G, Fagan AM, Mignot E, Zempel JM, Claassen JAHR, Holtzman DM. Slow wave sleep disruption increases cerebrospinal fluid amyloid-β levels. Brain 2017; 140:2104-2111. [PMID: 28899014 DOI: 10.1093/brain/awx148] [Citation(s) in RCA: 410] [Impact Index Per Article: 51.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 05/10/2017] [Indexed: 12/13/2022] Open
Abstract
See Mander et al. (doi:10.1093/awx174) for a scientific commentary on this article.Sleep deprivation increases amyloid-β, suggesting that chronically disrupted sleep may promote amyloid plaques and other downstream Alzheimer's disease pathologies including tauopathy or inflammation. To date, studies have not examined which aspect of sleep modulates amyloid-β or other Alzheimer's disease biomarkers. Seventeen healthy adults (age 35-65 years) without sleep disorders underwent 5-14 days of actigraphy, followed by slow wave activity disruption during polysomnogram, and cerebrospinal fluid collection the following morning for measurement of amyloid-β, tau, total protein, YKL-40, and hypocretin. Data were compared to an identical protocol, with a sham condition during polysomnogram. Specific disruption of slow wave activity correlated with an increase in amyloid-β40 (r = 0.610, P = 0.009). This effect was specific for slow wave activity, and not for sleep duration or efficiency. This effect was also specific to amyloid-β, and not total protein, tau, YKL-40, or hypocretin. Additionally, worse home sleep quality, as measured by sleep efficiency by actigraphy in the six nights preceding lumbar punctures, was associated with higher tau (r = 0.543, P = 0.045). Slow wave activity disruption increases amyloid-β levels acutely, and poorer sleep quality over several days increases tau. These effects are specific to neuronally-derived proteins, which suggests they are likely driven by changes in neuronal activity during disrupted sleep.
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Affiliation(s)
- Yo-El S Ju
- Department of Neurology, Washington University, Saint Louis, Missouri, USA.,Hope Center for Neurological Disorders, Washington University, Saint Louis, Missouri, USA
| | - Sharon J Ooms
- Department of Geriatric Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands.,Radboudumc Alzheimer Centre, Nijmegen, The Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Courtney Sutphen
- Department of Neurology, Washington University, Saint Louis, Missouri, USA.,Hope Center for Neurological Disorders, Washington University, Saint Louis, Missouri, USA
| | - Shannon L Macauley
- Department of Neurology, Washington University, Saint Louis, Missouri, USA.,Hope Center for Neurological Disorders, Washington University, Saint Louis, Missouri, USA
| | | | - Gina Jerome
- Department of Neurology, Washington University, Saint Louis, Missouri, USA.,Hope Center for Neurological Disorders, Washington University, Saint Louis, Missouri, USA
| | - Anne M Fagan
- Department of Neurology, Washington University, Saint Louis, Missouri, USA.,Hope Center for Neurological Disorders, Washington University, Saint Louis, Missouri, USA.,Knight Alzheimer's Disease Research Center, Washington University, Saint Louis, Missouri, USA
| | - Emmanuel Mignot
- Stanford Center for Sleep Sciences and Medicine, Stanford University, Palo Alto, California, USA
| | - John M Zempel
- Department of Neurology, Washington University, Saint Louis, Missouri, USA
| | - Jurgen A H R Claassen
- Department of Geriatric Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands.,Radboudumc Alzheimer Centre, Nijmegen, The Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - David M Holtzman
- Department of Neurology, Washington University, Saint Louis, Missouri, USA.,Hope Center for Neurological Disorders, Washington University, Saint Louis, Missouri, USA.,Knight Alzheimer's Disease Research Center, Washington University, Saint Louis, Missouri, USA
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406
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Schwalm M, Schmid F, Wachsmuth L, Backhaus H, Kronfeld A, Aedo Jury F, Prouvot PH, Fois C, Albers F, van Alst T, Faber C, Stroh A. Cortex-wide BOLD fMRI activity reflects locally-recorded slow oscillation-associated calcium waves. eLife 2017; 6:27602. [PMID: 28914607 PMCID: PMC5658067 DOI: 10.7554/elife.27602] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 09/14/2017] [Indexed: 01/08/2023] Open
Abstract
Spontaneous slow oscillation-associated slow wave activity represents an internally generated state which is characterized by alternations of network quiescence and stereotypical episodes of neuronal activity - slow wave events. However, it remains unclear which macroscopic signal is related to these active periods of the slow wave rhythm. We used optic fiber-based calcium recordings of local neural populations in cortex and thalamus to detect neurophysiologically defined slow calcium waves in isoflurane anesthetized rats. The individual slow wave events were used for an event-related analysis of simultaneously acquired whole-brain BOLD fMRI. We identified BOLD responses directly related to onsets of slow calcium waves, revealing a cortex-wide BOLD correlate: the entire cortex was engaged in this specific type of slow wave activity. These findings demonstrate a direct relation of defined neurophysiological events to a specific BOLD activity pattern and were confirmed for ongoing slow wave activity by independent component and seed-based analyses. When a person is in a deep non-dreaming sleep, neurons in their brain alternate slowly between periods of silence and periods of activity. This gives rise to low-frequency brain rhythms called slow waves, which are thought to help stabilize memories. Slow wave activity can be detected on multiple scales, from the pattern of electrical impulses sent by an individual neuron to the collective activity of the brain’s entire outer layer, the cortex. But does slow wave activity in an individual group of neurons in the cortex affect the activity of the rest of the brain? To find out, Schwalm, Schmid, Wachsmuth et al. took advantage of the fact that slow waves also occur under general anesthesia, and placed anesthetized rats inside miniature whole-brain scanners. A small region of cortex in each rat had been injected with a dye that fluoresces whenever the neurons in that region are active. An optical fiber was lowered into the rat’s brain to transmit the fluorescence signals to a computer. Monitoring these signals while the animals lay inside the scanner revealed that slow-wave activity in any one group of cortical neurons was accompanied by slow-wave activity across the cortex as a whole. This relationship was seen only for slow waves, and not for other brain rhythms. Slow waves seem to occur in all species of animal with a backbone, and in both healthy and diseased brains. While it is not possible to inject fluorescent dyes into the human brain, it is possible to monitor neuronal activity using electrodes. Comparing local electrode recordings with measures of whole-brain activity from scanners could thus allow similar experiments to be performed in people. There is growing evidence – from animal models and from studies of patients – that slow waves may be altered in Alzheimer’s disease. Further work is required to determine whether detecting these changes could help diagnose disease at earlier stages, and whether reversing them may have therapeutic potential.
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Affiliation(s)
- Miriam Schwalm
- Focus Program Translational Neurosciences, Institute for Microscopic Anatomy and Neurobiology, Johannes Gutenberg-University Mainz, Mainz, Germany.,GRADE Brain, Goethe Graduate Academy, Goethe University Frankfurt am Main, Frankfurt, Germany
| | - Florian Schmid
- Department of Clinical Radiology, University Hospital Münster, Münster, Germany
| | - Lydia Wachsmuth
- Department of Clinical Radiology, University Hospital Münster, Münster, Germany
| | - Hendrik Backhaus
- Focus Program Translational Neurosciences, Institute for Microscopic Anatomy and Neurobiology, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Andrea Kronfeld
- Focus Program Translational Neurosciences, Institute for Microscopic Anatomy and Neurobiology, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Felipe Aedo Jury
- Focus Program Translational Neurosciences, Institute for Microscopic Anatomy and Neurobiology, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Pierre-Hugues Prouvot
- Focus Program Translational Neurosciences, Institute for Microscopic Anatomy and Neurobiology, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Consuelo Fois
- Focus Program Translational Neurosciences, Institute for Microscopic Anatomy and Neurobiology, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Franziska Albers
- Department of Clinical Radiology, University Hospital Münster, Münster, Germany
| | - Timo van Alst
- Department of Clinical Radiology, University Hospital Münster, Münster, Germany
| | - Cornelius Faber
- Department of Clinical Radiology, University Hospital Münster, Münster, Germany
| | - Albrecht Stroh
- Focus Program Translational Neurosciences, Institute for Microscopic Anatomy and Neurobiology, Johannes Gutenberg-University Mainz, Mainz, Germany
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407
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Cox R, Schapiro AC, Manoach DS, Stickgold R. Individual Differences in Frequency and Topography of Slow and Fast Sleep Spindles. Front Hum Neurosci 2017; 11:433. [PMID: 28928647 PMCID: PMC5591792 DOI: 10.3389/fnhum.2017.00433] [Citation(s) in RCA: 125] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 08/15/2017] [Indexed: 11/25/2022] Open
Abstract
Sleep spindles are transient oscillatory waveforms that occur during non-rapid eye movement (NREM) sleep across widespread cortical areas. In humans, spindles can be classified as either slow or fast, but large individual differences in spindle frequency as well as methodological difficulties have hindered progress towards understanding their function. Using two nights of high-density electroencephalography recordings from 28 healthy individuals, we first characterize the individual variability of NREM spectra and demonstrate the difficulty of determining subject-specific spindle frequencies. We then introduce a novel spatial filtering approach that can reliably separate subject-specific spindle activity into slow and fast components that are stable across nights and across N2 and N3 sleep. We then proceed to provide detailed analyses of the topographical expression of individualized slow and fast spindle activity. Group-level analyses conform to known spatial properties of spindles, but also uncover novel differences between sleep stages and spindle classes. Moreover, subject-specific examinations reveal that individual topographies show considerable variability that is stable across nights. Finally, we demonstrate that topographical maps depend nontrivially on the spindle metric employed. In sum, our findings indicate that group-level approaches mask substantial individual variability of spindle dynamics, in both the spectral and spatial domains. We suggest that leveraging, rather than ignoring, such differences may prove useful to further our understanding of the physiology and functional role of sleep spindles.
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Affiliation(s)
- Roy Cox
- Department of Psychiatry, Beth Israel Deaconess Medical CenterBoston, MA, United States.,Department of Psychiatry, Harvard Medical SchoolBoston, MA, United States
| | - Anna C Schapiro
- Department of Psychiatry, Beth Israel Deaconess Medical CenterBoston, MA, United States.,Department of Psychiatry, Harvard Medical SchoolBoston, MA, United States
| | - Dara S Manoach
- Department of Psychiatry, Harvard Medical SchoolBoston, MA, United States.,Department of Psychiatry, Massachusetts General HospitalCharlestown, MA, United States.,Athinoula A. Martinos Center for Biomedical ImagingCharlestown, MA, United States
| | - Robert Stickgold
- Department of Psychiatry, Beth Israel Deaconess Medical CenterBoston, MA, United States.,Department of Psychiatry, Harvard Medical SchoolBoston, MA, United States
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408
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King BR, Hoedlmoser K, Hirschauer F, Dolfen N, Albouy G. Sleeping on the motor engram: The multifaceted nature of sleep-related motor memory consolidation. Neurosci Biobehav Rev 2017; 80:1-22. [DOI: 10.1016/j.neubiorev.2017.04.026] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 04/19/2017] [Accepted: 04/24/2017] [Indexed: 12/16/2022]
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409
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Stitt I, Hollensteiner KJ, Galindo-Leon E, Pieper F, Fiedler E, Stieglitz T, Engler G, Nolte G, Engel AK. Dynamic reconfiguration of cortical functional connectivity across brain states. Sci Rep 2017; 7:8797. [PMID: 28821753 PMCID: PMC5562766 DOI: 10.1038/s41598-017-08050-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 07/04/2017] [Indexed: 12/18/2022] Open
Abstract
Throughout each day, the brain displays transient changes in state, as evidenced by shifts in behavior and vigilance. While the electrophysiological correlates of brain states have been studied for some time, it remains unclear how large-scale cortico-cortical functional connectivity systematically reconfigures across states. Here, we investigate state-dependent shifts in cortical functional connectivity by recording local field potentials (LFPs) during spontaneous behavioral transitions in the ferret using chronically implanted micro-electrocorticographic (µECoG) arrays positioned over occipital, parietal, and temporal cortical regions. To objectively classify brain state, we describe a data-driven approach that projects time-varying LFP spectral properties into brain state space. Distinct brain states displayed markedly different patterns of cross-frequency phase-amplitude coupling and inter-electrode phase synchronization across several LFP frequency bands. The largest across-state differences in functional connectivity were observed between periods of presumed slow-wave and rapid-eye-movement-sleep/active-state, which were characterized by the contrasting phenomena of cortical network fragmentation and global synchronization, respectively. Collectively, our data provide strong evidence that large-scale functional interactions in the brain dynamically reconfigure across behavioral states.
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Affiliation(s)
- Iain Stitt
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany. .,Department of Psychiatry, Neuroscience Center, University of North Carolina, Chapel Hill, NC, 27514, USA.
| | - Karl J Hollensteiner
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Edgar Galindo-Leon
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Florian Pieper
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Eva Fiedler
- Department of Microsystems Engineering, University of Freiburg, 79110, Freiburg, Germany
| | - Thomas Stieglitz
- Department of Microsystems Engineering, University of Freiburg, 79110, Freiburg, Germany
| | - Gerhard Engler
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Guido Nolte
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Andreas K Engel
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
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410
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Abstract
Alzheimer's disease (AD) is increasing in prevalence and has a significant impact on caregivers and the healthcare system. One of the many physiologic process affected by AD is the circadian system, with disruption reflected in abnormalities of the sleep-wake cycle. This interaction is bidirectional, with circadian and sleep disruption influencing disease progression. Understanding the bidirectional relationship between AD and circadian disruption may allow for earlier recognition of the potential to develop dementia as well as improved targeted approaches for therapy. Therapies including melatonin and bright light therapy may be advantageous in improving sleep and circadian rhythms and preventing the progression of disease. However, unfortunately, these modalities are not curative, and additional research is needed to improve treatment options for these individuals.
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Affiliation(s)
- Yumna Saeed
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Sabra M Abbott
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
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411
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Role of Somatostatin-Positive Cortical Interneurons in the Generation of Sleep Slow Waves. J Neurosci 2017; 37:9132-9148. [PMID: 28821651 DOI: 10.1523/jneurosci.1303-17.2017] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 07/03/2017] [Accepted: 08/08/2017] [Indexed: 02/05/2023] Open
Abstract
During non-rapid eye-movement (NREM) sleep, cortical and thalamic neurons oscillate every second or so between ON periods, characterized by membrane depolarization and wake-like tonic firing, and OFF periods, characterized by membrane hyperpolarization and neuronal silence. Cortical slow waves, the hallmark of NREM sleep, reflect near-synchronous OFF periods in cortical neurons. However, the mechanisms triggering such OFF periods are unclear, as there is little evidence for somatic inhibition. We studied cortical inhibitory interneurons that express somatostatin (SOM), because ∼70% of them are Martinotti cells that target diffusely layer I and can block excitatory transmission presynaptically, at glutamatergic terminals, and postsynaptically, at apical dendrites, without inhibiting the soma. In freely moving male mice, we show that SOM+ cells can fire immediately before slow waves and their optogenetic stimulation during ON periods of NREM sleep triggers long OFF periods. Next, we show that chemogenetic activation of SOM+ cells increases slow-wave activity (SWA), slope of individual slow waves, and NREM sleep duration; whereas their chemogenetic inhibition decreases SWA and slow-wave incidence without changing time spent in NREM sleep. By contrast, activation of parvalbumin+ (PV+) cells, the most numerous population of cortical inhibitory neurons, greatly decreases SWA and cortical firing, triggers short OFF periods in NREM sleep, and increases NREM sleep duration. Thus SOM+ cells, but not PV+ cells, are involved in the generation of sleep slow waves. Whether Martinotti cells are solely responsible for this effect, or are complemented by other classes of inhibitory neurons, remains to be investigated.SIGNIFICANCE STATEMENT Cortical slow waves are a defining feature of non-rapid eye-movement (NREM) sleep and are thought to be important for many of its restorative benefits. Yet, the mechanism by which cortical neurons abruptly and synchronously cease firing, the neuronal basis of the slow wave, remains unknown. Using chemogenetic and optogenetic approaches, we provide the first evidence that links a specific class of inhibitory interneurons-somatostatin-positive cells-to the generation of slow waves during NREM sleep in freely moving mice.
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412
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Optogenetic Investigation of Arousal Circuits. Int J Mol Sci 2017; 18:ijms18081773. [PMID: 28809797 PMCID: PMC5578162 DOI: 10.3390/ijms18081773] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Revised: 08/06/2017] [Accepted: 08/09/2017] [Indexed: 12/13/2022] Open
Abstract
Modulation between sleep and wake states is controlled by a number of heterogeneous neuron populations. Due to the topological proximity and genetic co-localization of the neurons underlying sleep-wake state modulation optogenetic methods offer a significant improvement in the ability to benefit from both the precision of genetic targeting and millisecond temporal control. Beginning with an overview of the neuron populations mediating arousal, this review outlines the progress that has been made in the investigation of arousal circuits since the incorporation of optogenetic techniques and the first in vivo application of optogenetic stimulation in hypocretin neurons in the lateral hypothalamus. This overview is followed by a discussion of the future progress that can be made by incorporating more recent technological developments into the research of neural circuits.
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413
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Epileptic interictal discharges are more frequent during NREM slow wave downstates. Neurosci Lett 2017; 658:37-42. [PMID: 28811195 DOI: 10.1016/j.neulet.2017.08.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 07/26/2017] [Accepted: 08/08/2017] [Indexed: 11/22/2022]
Abstract
Epileptiform activity in various but not all epilepsy and recording types and cerebral areas is more frequent in NREM sleep, and especially during sleep periods with high-amplitude EEG slow waves. Slow waves synchronize high-frequency oscillations: physiological activity from the theta through the gamma band usually appears during scalp-positive upstates while epileptiform activity occurs at transitory phases and the scalp-negative downstate. It has been proposed that interictal discharges (IIDs) are facilitated by the high degree of neuronal firing synchrony during slow wave transitory and downstates. This would suggest that their occurrence increases as a function of slow wave synchronization, indicated by greater amplitude, steeper slopes and higher EEG signal synchronization. We investigated the occurrence of IIDs during NREM sleep slow waves in epileptic patients undergoing presurgical electrophysiological monitoring. Intracranially registered IIDs preferentially occurred during the scalp-negative downstates of frontal scalp slow waves in all subjects. IID occurrence was more frequent during larger slow waves in the pooled sample and a subset of subjects. However, slow wave slope steepness and EEG signal synchronization between two frontal scalp channels was not significantly associated with IID occurrence. Our results indicate that IIDs indeed do not occur at the same slow wave phase as physiological rhythms, but contrary to previous hypotheses their occurrence is not strongly affected by EEG synchronization.
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414
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Flores FJ, Hartnack KE, Fath AB, Kim SE, Wilson MA, Brown EN, Purdon PL. Thalamocortical synchronization during induction and emergence from propofol-induced unconsciousness. Proc Natl Acad Sci U S A 2017; 114:E6660-E6668. [PMID: 28743752 PMCID: PMC5558998 DOI: 10.1073/pnas.1700148114] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
General anesthesia (GA) is a reversible drug-induced state of altered arousal required for more than 60,000 surgical procedures each day in the United States alone. Sedation and unconsciousness under GA are associated with stereotyped electrophysiological oscillations that are thought to reflect profound disruptions of activity in neuronal circuits that mediate awareness and cognition. Computational models make specific predictions about the role of the cortex and thalamus in these oscillations. In this paper, we provide in vivo evidence in rats that alpha oscillations (10-15 Hz) induced by the commonly used anesthetic drug propofol are synchronized between the thalamus and the medial prefrontal cortex. We also show that at deep levels of unconsciousness where movement ceases, coherent thalamocortical delta oscillations (1-5 Hz) develop, distinct from concurrent slow oscillations (0.1-1 Hz). The structure of these oscillations in both cortex and thalamus closely parallel those observed in the human electroencephalogram during propofol-induced unconsciousness. During emergence from GA, this synchronized activity dissipates in a sequence different from that observed during loss of consciousness. A possible explanation is that recovery from anesthesia-induced unconsciousness follows a "boot-up" sequence actively driven by ascending arousal centers. The involvement of medial prefrontal cortex suggests that when these oscillations (alpha, delta, slow) are observed in humans, self-awareness and internal consciousness would be impaired if not abolished. These studies advance our understanding of anesthesia-induced unconsciousness and altered arousal and further establish principled neurophysiological markers of these states.
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Affiliation(s)
- Francisco J Flores
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, MA 02114;
- Harvard Medical School, Boston, MA 02115
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Katharine E Hartnack
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, MA 02114
| | - Amanda B Fath
- Department of Neuroscience, Wellesley College, Wellesley, MA 02481
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Seong-Eun Kim
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Matthew A Wilson
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Emery N Brown
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, MA 02114;
- Harvard Medical School, Boston, MA 02115
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139
- Institute of Medical Engineering and Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Patrick L Purdon
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, MA 02114;
- Harvard Medical School, Boston, MA 02115
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415
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Formation and suppression of acoustic memories during human sleep. Nat Commun 2017; 8:179. [PMID: 28790302 PMCID: PMC5548898 DOI: 10.1038/s41467-017-00071-z] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 05/30/2017] [Indexed: 11/09/2022] Open
Abstract
Sleep and memory are deeply related, but the nature of the neuroplastic processes induced by sleep remains unclear. Here, we report that memory traces can be both formed or suppressed during sleep, depending on sleep phase. We played samples of acoustic noise to sleeping human listeners. Repeated exposure to a novel noise during Rapid Eye Movements (REM) or light non-REM (NREM) sleep leads to improvements in behavioral performance upon awakening. Strikingly, the same exposure during deep NREM sleep leads to impaired performance upon awakening. Electroencephalographic markers of learning extracted during sleep confirm a dissociation between sleep facilitating memory formation (light NREM and REM sleep) and sleep suppressing learning (deep NREM sleep). We can trace these neural changes back to transient sleep events, such as spindles for memory facilitation and slow waves for suppression. Thus, highly selective memory processes are active during human sleep, with intertwined episodes of facilitative and suppressive plasticity.Though memory and sleep are related, it is still unclear whether new memories can be formed during sleep. Here, authors show that people could learn new sounds during REM or light non-REM sleep, but that learning was suppressed when sounds were played during deep NREM sleep.
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416
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Abstract
Scientific investigation into the possible role of sleep in memory consolidation began with the early studies of Jenkins and Dallenbach (1924). Despite nearly a century of investigation with a waxing and waning of interest, the role of sleep in memory processing remains controversial and elusive. This review provides the historical background for current views and considers the relative contribution of two sleep states, rapid eye movement sleep and slow-wave sleep, to offline memory processing. The sequential hypothesis, until now largely ignored, is discussed, and recent literature supporting this view is reviewed.
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417
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Electrophysiological and microstructural features of sleep in children at high risk for depression: a preliminary study. Sleep Med 2017; 36:95-103. [DOI: 10.1016/j.sleep.2017.05.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Revised: 05/02/2017] [Accepted: 05/03/2017] [Indexed: 01/29/2023]
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418
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Allada R, Cirelli C, Sehgal A. Molecular Mechanisms of Sleep Homeostasis in Flies and Mammals. Cold Spring Harb Perspect Biol 2017; 9:a027730. [PMID: 28432135 PMCID: PMC5538413 DOI: 10.1101/cshperspect.a027730] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Sleep is homeostatically regulated with sleep pressure accumulating with the increasing duration of prior wakefulness. Yet, a clear understanding of the molecular components of the homeostat, as well as the molecular and cellular processes they sense and control to regulate sleep intensity and duration, remain a mystery. Here, we will discuss the cellular and molecular basis of sleep homeostasis, first focusing on the best homeostatic sleep marker in vertebrates, slow wave activity; second, moving to the molecular genetic analysis of sleep homeostasis in the fruit fly Drosophila; and, finally, discussing more systemic aspects of sleep homeostasis.
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Affiliation(s)
- Ravi Allada
- Department of Neurobiology, Northwestern University, Evanston, Ilinois 60208
| | - Chiara Cirelli
- Department of Psychiatry, University of Wisconsin-Madison, Madison, Wisconsin 53719
| | - Amita Sehgal
- Department of Neuroscience, Perelman School of Medicine at University of Pennsylvania, Philadelphia, Pennsylvania 19104-6058
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419
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Carpentier N, Cecchin T, Koessler L, Louis-Dorr V, Jonas J, Vignal JP, Carpentier M, Szurhaj W, Bourgin P, Maillard L. Stereo-electroencephalography identifies N2 sleep and spindles in human hippocampus. Clin Neurophysiol 2017; 128:1696-1706. [PMID: 28755545 DOI: 10.1016/j.clinph.2017.06.248] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 05/17/2017] [Accepted: 06/15/2017] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To describe the hippocampal stereo-electroencephalogram during sleep according to sleep stages (including N2 sleep) and cycles, together with the hippocampal spindles. METHODS All patients with drug-resistant focal epilepsy undergoing intra-hippocampal implantation between August 2012 and June 2013 at Nancy University Hospital were screened. Six patients with explored hippocampus devoid of pathological features were analyzed. During one night, we identified continuous periods of successive N2, N3 and REM sleep for two full cycles. We performed a spectral analysis of the hippocampal signal for each labeled sleep period. RESULTS N2, N3 and REM sleeps were individualized according to their spectral powers, for each frequency band and sleep cycle. Hippocampal spindles showed dynamic intrinsic properties, the 11.5-16Hz frequency band being mainly dominant, whereas the 9-11.5Hz frequency band heightening during the beginning and the end of the transient. For N3 and REM sleep stages, the power of the hippocampal signal was significantly decreased between the first and the second sleep cycle. CONCLUSION Distinct N2 sleep, fast spindles and homeostatic profile are all common properties shared by hippocampus and cortex during sleep. SIGNIFICANCE The close functional link between hippocampus and cortex may have various sleep-related substrates.
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Affiliation(s)
| | - Thierry Cecchin
- CNRS, CRAN, UMR 7039, Nancy, France; Université de Lorraine, CRAN, UMR 7039, Nancy, France
| | - Laurent Koessler
- CNRS, CRAN, UMR 7039, Nancy, France; Université de Lorraine, CRAN, UMR 7039, Nancy, France
| | - Valérie Louis-Dorr
- CNRS, CRAN, UMR 7039, Nancy, France; Université de Lorraine, CRAN, UMR 7039, Nancy, France
| | - Jacques Jonas
- Department of Neurology, Nancy University Hospital, Nancy, France; CNRS, CRAN, UMR 7039, Nancy, France; Université de Lorraine, CRAN, UMR 7039, Nancy, France
| | - Jean-Pierre Vignal
- Department of Neurology, Nancy University Hospital, Nancy, France; CNRS, CRAN, UMR 7039, Nancy, France; Université de Lorraine, CRAN, UMR 7039, Nancy, France
| | - Marc Carpentier
- Division of Clinical Epidemiology, Geneva University Hospitals, Geneva, Switzerland
| | - William Szurhaj
- Department of Neurology, Salengro University Hospital, Lille, France
| | - Patrice Bourgin
- Sleep Disorder Center and CNRS UPR3212, Strasbourg University Hospital, Strasbourg, France
| | - Louis Maillard
- Department of Neurology, Nancy University Hospital, Nancy, France; CNRS, CRAN, UMR 7039, Nancy, France; Université de Lorraine, CRAN, UMR 7039, Nancy, France
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420
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Lowe CJ, Safati A, Hall PA. The neurocognitive consequences of sleep restriction: A meta-analytic review. Neurosci Biobehav Rev 2017; 80:586-604. [PMID: 28757454 DOI: 10.1016/j.neubiorev.2017.07.010] [Citation(s) in RCA: 277] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 05/26/2017] [Accepted: 07/24/2017] [Indexed: 01/17/2023]
Abstract
The current meta-analytic review evaluated the effects of experimentally manipulated sleep restriction on neurocognitive functioning. Random-effects models were employed to estimate the overall effect size and the differential effect size across cognitive domains. Age, time of day, age-adjusted sleep deficit, cumulative days of restricted sleep, sleep latency, subjective sleepiness, and biological sex were examined as potential moderators of the effect. Based on a sample of 61 studies, from 71 different populations, findings revealed a significant negative effect of sleep restriction on cognitive processing across cognitive domains (g=-0.383, p<0.001). This effect held for executive functioning (g=-0.324, p<0.001), sustained attention (g=-0.409, p<0.001), and long-term memory (g=-0.192, p=0.002). There was insufficient evidence to detect an effect within the domains of attention, multitask, impulsive decision-making or intelligence. Age group, time of day, cumulative days of restricted sleep, sleep latency, subjective sleepiness, and biological sex were all significant moderators of the overall effect. In conclusion, the current meta-analysis is the first comprehensive review to provide evidence that short-term sleep restriction significantly impairs waking neurocognitive functioning.
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Affiliation(s)
- Cassandra J Lowe
- School of Public Health and Health Systems, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.
| | - Adrian Safati
- School of Public Health and Health Systems, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Peter A Hall
- School of Public Health and Health Systems, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
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421
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Fogerson PM, Huguenard JR. Tapping the Brakes: Cellular and Synaptic Mechanisms that Regulate Thalamic Oscillations. Neuron 2017; 92:687-704. [PMID: 27883901 DOI: 10.1016/j.neuron.2016.10.024] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 10/03/2016] [Accepted: 10/10/2016] [Indexed: 12/26/2022]
Abstract
Thalamic oscillators contribute to both normal rhythms associated with sleep and anesthesia and abnormal, hypersynchronous oscillations that manifest behaviorally as absence seizures. In this review, we highlight new findings that refine thalamic contributions to cortical rhythms and suggest that thalamic oscillators may be subject to both local and global control. We describe endogenous thalamic mechanisms that limit network synchrony and discuss how these protective brakes might be restored to prevent absence seizures. Finally, we describe how intrinsic and circuit-level specializations among thalamocortical loops may determine their involvement in widespread oscillations and render subsets of thalamic nuclei especially vulnerable to pathological synchrony.
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Affiliation(s)
- P Michelle Fogerson
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - John R Huguenard
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA.
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422
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Coordinated Interaction between Hippocampal Sharp-Wave Ripples and Anterior Cingulate Unit Activity. J Neurosci 2017; 36:10663-10672. [PMID: 27733616 DOI: 10.1523/jneurosci.1042-16.2016] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 08/30/2016] [Indexed: 11/21/2022] Open
Abstract
Hippocampal-cortical interaction during sleep promotes transformation of memory for long-term storage in the cortex. In particular, hippocampal sharp-wave ripple-associated neural activation is important for this transformation during slow-wave sleep. The anterior cingulate cortex (ACC) has been shown to be crucial for expression and likely storage of long-term memory. However, little is known about how ACC activity is influenced by hippocampal ripple activity during sleep. We report here about coordinated interactions between hippocampal ripple activity and ACC neural firings. By recording from the ACC and hippocampal CA1 simultaneously in mice, we found that almost all ACC neurons showed increased activity before hippocampal ripple activity; moreover, a subpopulation (17%) displayed a further activation immediately after ripple activity. This postripple activation of ACC neurons correlated positively with ripple amplitude, and the same neurons were excited upon electrical stimulation of the CA1. Interestingly, the preripple activation of ACC neurons was present during the sleep state, but not during the awake state. These results suggest intimate interactions between hippocampal sharp-wave ripples and ACC neurons in a state-dependent manner. Importantly, sharp-wave ripples and associated activation appear to regulate activity of a small population of ACC neurons, a process that may play a critical role in memory consolidation. SIGNIFICANCE STATEMENT The hippocampus communicates with the cortex for memory transformation. Memories of previous experiences become less dependent on the hippocampus and increasingly dependent on cortical areas, such as the anterior cingulate cortex (ACC). However, little evidence is available to directly support this hippocampus-to-cortex information transduction hypothesis of memory consolidation. Here we show that a subpopulation of ACC neurons becomes active just after hippocampal ripple activity, and that electrical stimulation of the hippocampus excites the same ACC neurons. In addition, the majority of ACC neurons are activated just before ripple activity during the sleep state, but not during the awake state. These results provide evidence supporting the hypothesis of hippocampus-to-cortex information flow for memory consolidation as well as reciprocal interaction between the hippocampus and the cortex.
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423
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Neural Markers of Responsiveness to the Environment in Human Sleep. J Neurosci 2017; 36:6583-96. [PMID: 27307244 DOI: 10.1523/jneurosci.0902-16.2016] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 05/14/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Sleep is characterized by a loss of behavioral responsiveness. However, recent research has shown that the sleeping brain is not completely disconnected from its environment. How neural activity constrains the ability to process sensory information while asleep is yet unclear. Here, we instructed human volunteers to classify words with lateralized hand responses while falling asleep. Using an electroencephalographic (EEG) marker of motor preparation, we show how responsiveness is modulated across sleep. These modulations are tracked using classic event-related potential analyses complemented by Lempel-Ziv complexity (LZc), a measure shown to track arousal in sleep and anesthesia. Neural activity related to the semantic content of stimuli was conserved in light non-rapid eye movement (NREM) sleep. However, these processes were suppressed in deep NREM sleep and, importantly, also in REM sleep, despite the recovery of wake-like neural activity in the latter. In NREM sleep, sensory activations were counterbalanced by evoked down states, which, when present, blocked further processing of external information. In addition, responsiveness markers correlated positively with baseline complexity, which could be related to modulation in sleep depth. In REM sleep, however, this relationship was reversed. We therefore propose that, in REM sleep, endogenously generated processes compete with the processing of external input. Sleep can thus be seen as a self-regulated process in which external information can be processed in lighter stages but suppressed in deeper stages. Last, our results suggest drastically different gating mechanisms in NREM and REM sleep. SIGNIFICANCE STATEMENT Previous research has tempered the notion that sleepers are isolated from their environment. Here, we pushed this idea forward and examined, across all sleep stages, the brain's ability to flexibly process sensory information, up to the decision level. We extracted an EEG marker of motor preparation to determine the completion of the sensory processing chain and explored how it is constrained by baseline and evoked neural activity. In NREM sleep, slow waves elicited by stimuli appeared to block response preparation. We also used a novel analytic approach (Lempel-Ziv complexity) and showed that the ability to process external information correlates with neural complexity. A reversal of the correlation between complexity and motor indices in REM sleep suggests drastically different gating mechanisms across sleep stages.
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424
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Increased Stability and Breakdown of Brain Effective Connectivity During Slow-Wave Sleep: Mechanistic Insights from Whole-Brain Computational Modelling. Sci Rep 2017; 7:4634. [PMID: 28680119 PMCID: PMC5498661 DOI: 10.1038/s41598-017-04522-x] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 05/16/2017] [Indexed: 11/08/2022] Open
Abstract
Recent research has found that the human sleep cycle is characterised by changes in spatiotemporal patterns of brain activity. Yet, we are still missing a mechanistic explanation of the local neuronal dynamics underlying these changes. We used whole-brain computational modelling to study the differences in global brain functional connectivity and synchrony of fMRI activity in healthy humans during wakefulness and slow-wave sleep. We applied a whole-brain model based on the normal form of a supercritical Hopf bifurcation and studied the dynamical changes when adapting the bifurcation parameter for all brain nodes to best match wakefulness and slow-wave sleep. Furthermore, we analysed differences in effective connectivity between the two states. In addition to significant changes in functional connectivity, synchrony and metastability, this analysis revealed a significant shift of the global dynamic working point of brain dynamics, from the edge of the transition between damped to sustained oscillations during wakefulness, to a stable focus during slow-wave sleep. Moreover, we identified a significant global decrease in effective interactions during slow-wave sleep. These results suggest a mechanism for the empirical functional changes observed during slow-wave sleep, namely a global shift of the brain's dynamic working point leading to increased stability and decreased effective connectivity.
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425
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Macedo AC, Balouch S, Tabet N. Is Sleep Disruption a Risk Factor for Alzheimer’s Disease? J Alzheimers Dis 2017; 58:993-1002. [DOI: 10.3233/jad-161287] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
| | - Sara Balouch
- Centre for Dementia Studies, Brighton and Sussex Medical School, Brighton, England, UK
| | - Naji Tabet
- Centre for Dementia Studies, Brighton and Sussex Medical School, Brighton, England, UK
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426
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Zubler F, Rubino A, Lo Russo G, Schindler K, Nobili L. Correlating Interictal Spikes with Sigma and Delta Dynamics during Non-Rapid-Eye-Movement-Sleep. Front Neurol 2017; 8:288. [PMID: 28690583 PMCID: PMC5479894 DOI: 10.3389/fneur.2017.00288] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 06/02/2017] [Indexed: 01/21/2023] Open
Abstract
Interictal spikes (IS) are one of the major hallmarks of epilepsy. Understanding the factors promoting or suppressing IS would increase our comprehension of epilepsy and possibly open new avenues for therapy. Sleep strongly influences epileptic activity, and the modulatory effects of the different sleep stages on IS have been studied for decades. However, several aspects are still disputed, in particular the role of sleep spindles and slow waves in the activation of IS during Non-REM sleep. Here, we correlate the rate of IS with quantitative measures derived from stereo-EEG during one Non-REM cycle in 10 patients suffering from drug-resistant epilepsy due to type 2 focal cortical dysplasia. We show that the IS rate (ISR) is positively correlated with sigma power (a surrogate for sleep-spindle density) but negatively correlated with delta power (surrogate for slow wave activity). In addition, we present two new indices for quantifying the spatial and temporal instability of sleep. We found that both instability indices are correlated with a high ISR. The main contribution of this study is to confirm the suppressive effect of stable deep sleep on IS. This result might influence future guidelines for therapy of patients suffering from epilepsy and sleep disorders.
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Affiliation(s)
- Frédéric Zubler
- "C. Munari" Center for Epilepsy Surgery, Department of Neuroscience, Niguarda Hospital, Milan, Italy
| | - Annalisa Rubino
- "C. Munari" Center for Epilepsy Surgery, Department of Neuroscience, Niguarda Hospital, Milan, Italy
| | - Giorgio Lo Russo
- "C. Munari" Center for Epilepsy Surgery, Department of Neuroscience, Niguarda Hospital, Milan, Italy
| | - Kaspar Schindler
- Department of Neurology, Inselspital-Bern University Hospital, University of Bern, Bern, Switzerland
| | - Lino Nobili
- "C. Munari" Center for Epilepsy Surgery, Department of Neuroscience, Niguarda Hospital, Milan, Italy
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427
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Sleep Problems in Alzheimer’s Disease. CURRENT SLEEP MEDICINE REPORTS 2017. [DOI: 10.1007/s40675-017-0076-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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428
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Ioannides AA, Liu L, Poghosyan V, Kostopoulos GK. Using MEG to Understand the Progression of Light Sleep and the Emergence and Functional Roles of Spindles and K-Complexes. Front Hum Neurosci 2017; 11:313. [PMID: 28670270 PMCID: PMC5472839 DOI: 10.3389/fnhum.2017.00313] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2017] [Accepted: 05/31/2017] [Indexed: 12/20/2022] Open
Abstract
We used tomographic analysis of MEG signals to characterize regional spectral changes in the brain at sleep onset and during light sleep. We identified two key processes that may causally link to loss of consciousness during the quiet or "core" periods of NREM1. First, active inhibition in the frontal lobe leads to delta and theta spectral power increases. Second, activation suppression leads to sharp drop of spectral power in alpha and higher frequencies in posterior parietal cortex. During NREM2 core periods, the changes identified in NREM1 become more widespread, but focal increases also emerge in alpha and low sigma band power in frontal midline cortical structures, suggesting reemergence of some monitoring of internal and external environment. Just before spindles and K-complexes (KCs), the hallmarks of NREM2, we identified focal spectral power changes in pre-frontal cortex, mid cingulate, and areas involved in environmental and internal monitoring, i.e., the rostral and sub-genual anterior cingulate. During both spindles and KCs, alpha and low sigma bands increases. Spindles emerge after further active inhibition (increase in delta power) of the frontal areas responsible for environmental monitoring, while in posterior parietal cortex, power increases in low and high sigma bands. KCs are correlated with increase in alpha power in the monitoring areas. These specific regional changes suggest strong and varied vigilance changes for KCs, but vigilance suppression and sharpening of cognitive processing for spindles. This is consistent with processes designed to ensure accurate and uncorrupted memory consolidation. The changes during KCs suggest a sentinel role: evaluation of the salience of provoking events to decide whether to increase processing and possibly wake up, or to actively inhibit further processing of intruding influences. The regional spectral patterns of NREM1, NREM2, and their dynamic changes just before spindles and KCs reveal an edge effect facilitating the emergence of spindles and KCs and defining the precise loci where they might emerge. In the time domain, the spindles are seen in widespread areas of the cortex just as reported from analysis of intracranial data, consistent with the emerging consensus of a differential topography that depends on the kind of memory stored.
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Affiliation(s)
- Andreas A. Ioannides
- Laboratory for Human Brain Dynamics, AAI Scientific Cultural Services Ltd.Nicosia, Cyprus
| | - Lichan Liu
- Laboratory for Human Brain Dynamics, AAI Scientific Cultural Services Ltd.Nicosia, Cyprus
| | - Vahe Poghosyan
- Laboratory for Human Brain Dynamics, AAI Scientific Cultural Services Ltd.Nicosia, Cyprus
- MEG Unit, Department of Neurophysiology, King Fahad Medical CityRiyadh, Saudi Arabia
| | - George K. Kostopoulos
- Neurophysiology Unit, Department of Physiology, Medical School, University of PatrasRion, Greece
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429
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Sleep spindle characteristics in overweight adolescents with obstructive sleep apnea syndrome. Sleep Biol Rhythms 2017. [DOI: 10.1007/s41105-017-0104-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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430
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Akeju O, Brown EN. Neural oscillations demonstrate that general anesthesia and sedative states are neurophysiologically distinct from sleep. Curr Opin Neurobiol 2017; 44:178-185. [PMID: 28544930 PMCID: PMC5520989 DOI: 10.1016/j.conb.2017.04.011] [Citation(s) in RCA: 124] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 04/17/2017] [Accepted: 04/26/2017] [Indexed: 11/19/2022]
Abstract
General anesthesia is a man-made neurophysiological state comprised of unconsciousness, amnesia, analgesia, and immobility along with maintenance of physiological stability. Growing evidence suggests that anesthetic-induced neural oscillations are a primary mechanism of anesthetic action. Each anesthetic drug class produces distinct oscillatory dynamics that can be related to the circuit mechanisms of drug action. Sleep is a naturally occurring state of decreased arousal that is essential for normal health. Physiological measurements (electrooculogram, electromyogram) and neural oscillatory (electroencephalogram) dynamics are used to empirically characterize sleep into rapid eye movement sleep and the three stages of non-rapid eye movement sleep. In this review, we discuss the differences between anesthesia- and sleep-induced altered states from the perspective of neural oscillations.
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Affiliation(s)
- Oluwaseun Akeju
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States.
| | - Emery N Brown
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States; Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States.
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431
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Perogamvros L, Baird B, Seibold M, Riedner B, Boly M, Tononi G. The Phenomenal Contents and Neural Correlates of Spontaneous Thoughts across Wakefulness, NREM Sleep, and REM Sleep. J Cogn Neurosci 2017; 29:1766-1777. [PMID: 28562209 DOI: 10.1162/jocn_a_01155] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Thoughts occur during wake as well as during dreaming sleep. Using experience sampling combined with high-density EEG, we investigated the phenomenal qualities and neural correlates of spontaneously occurring thoughts across wakefulness, non-rapid eye movement (NREM) sleep, and REM sleep. Across all states, thoughts were associated with activation of a region of the midcingulate cortex. Thoughts during wakefulness additionally involved a medial prefrontal region, which was associated with metacognitive thoughts during wake. Phenomenologically, waking thoughts had more metacognitive content than thoughts during both NREM and REM sleep, whereas thoughts during REM sleep had a more social content. Together, these results point to a core neural substrate for thoughts, regardless of behavioral state, within the midcingulate cortex, and suggest that medial prefrontal regions may contribute to metacognitive content in waking thoughts.
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Affiliation(s)
- Lampros Perogamvros
- University of Wisconsin-Madison.,Geneva University Hospitals.,University of Geneva
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432
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Siclari F, Tononi G. Local aspects of sleep and wakefulness. Curr Opin Neurobiol 2017; 44:222-227. [PMID: 28575720 DOI: 10.1016/j.conb.2017.05.008] [Citation(s) in RCA: 131] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Accepted: 05/11/2017] [Indexed: 11/19/2022]
Abstract
Slow waves, the hallmark of NREM (Non Rapid Eye Movement) sleep, are not uniformly distributed across the cortical surface, but can occur locally and asynchronously across brain regions. Their regional distribution and amplitude is affected by brain maturation and by time spent awake, mediated in part by experience-dependent changes in synaptic strength. Recent studies have shown that local low-frequency oscillations (<10Hz) can also occur in REM sleep and during wakefulness, leading to region-specific cognitive errors. Local decreases and increases of slow wave activity in posterior brain regions have been linked to the occurrence of dreaming and to unconscious sleep, respectively. Finally, the coexistence of local sleep-like and wake-like patterns in different brain areas is characteristic of several sleep disorders and may offer insights into these conditions.
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Affiliation(s)
- Francesca Siclari
- Center for Research and Investigation on Sleep (CIRS), Lausanne University Hospital (CHUV) and University of Lausanne, Rue du Bugnon 46, 1011 Lausanne, Switzerland; Department of Psychiatry, University of Wisconsin-Madison, 6001 Research Park Boulevard Madison, WI 53519, USA.
| | - Giulio Tononi
- Department of Psychiatry, University of Wisconsin-Madison, 6001 Research Park Boulevard Madison, WI 53519, USA.
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433
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Mak-McCully RA, Rolland M, Sargsyan A, Gonzalez C, Magnin M, Chauvel P, Rey M, Bastuji H, Halgren E. Coordination of cortical and thalamic activity during non-REM sleep in humans. Nat Commun 2017; 8:15499. [PMID: 28541306 PMCID: PMC5458505 DOI: 10.1038/ncomms15499] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 03/29/2017] [Indexed: 11/21/2022] Open
Abstract
Every night, the human brain produces thousands of downstates and spindles during non-REM sleep. Previous studies indicate that spindles originate thalamically and downstates cortically, loosely grouping spindle occurrence. However, the mechanisms whereby the thalamus and cortex interact in generating these sleep phenomena remain poorly understood. Using bipolar depth recordings, we report here a sequence wherein: (1) convergent cortical downstates lead thalamic downstates; (2) thalamic downstates hyperpolarize thalamic cells, thus triggering spindles; and (3) thalamic spindles are focally projected back to cortex, arriving during the down-to-upstate transition when the cortex replays memories. Thalamic intrinsic currents, therefore, may not be continuously available during non-REM sleep, permitting the cortex to control thalamic spindling by inducing downstates. This archetypical cortico-thalamo-cortical sequence could provide the global physiological context for memory consolidation during non-REM sleep. During non-REM sleep, the thalamus produces spindles and the cortex produces downstates, but the interaction between these two areas in these sleep phenomena is not understood. Here, authors describe the dynamic loop between the thalamus and cortex that organizes the production of spindles and downstates in the human brain.
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Affiliation(s)
- Rachel A Mak-McCully
- Department of Neurosciences, University of California, San Diego, California 92093, USA
| | - Matthieu Rolland
- Department of Radiology, University of California, San Diego, California 92093, USA
| | - Anna Sargsyan
- Department of Radiology, University of California, San Diego, California 92093, USA
| | - Chris Gonzalez
- Department of Neurosciences, University of California, San Diego, California 92093, USA
| | - Michel Magnin
- Central Integration of Pain, Lyon Neuroscience Research Center, INSERM, U1028; CNRS, UMR5292; Université Claude Bernard, Lyon, Bron, France
| | - Patrick Chauvel
- Aix-Marseille Université, 13385 Marseille, France.,INSERM, Institut de Neurosciences des Systèmes UMR 1106, 13005 Marseille, France.,APHM (Assistance Publique-Hôpitaux de Marseille), Timone Hospital, 13005 Marseille, France
| | - Marc Rey
- Aix-Marseille Université, 13385 Marseille, France.,INSERM, Institut de Neurosciences des Systèmes UMR 1106, 13005 Marseille, France.,APHM (Assistance Publique-Hôpitaux de Marseille), Timone Hospital, 13005 Marseille, France
| | - Hélène Bastuji
- Central Integration of Pain, Lyon Neuroscience Research Center, INSERM, U1028; CNRS, UMR5292; Université Claude Bernard, Lyon, Bron, France.,Unité d'Hypnologie, Service de Neurologie Fonctionnelle et d'Épileptologie, Hôpital Neurologique, Hospices Civils de Lyon, Bron 69002, France
| | - Eric Halgren
- Department of Neurosciences, University of California, San Diego, California 92093, USA.,Department of Radiology, University of California, San Diego, California 92093, USA.,Department of Psychiatry, University of California, San Diego, California 92093, USA
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434
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Eban-Rothschild A, Giardino WJ, de Lecea L. To sleep or not to sleep: neuronal and ecological insights. Curr Opin Neurobiol 2017; 44:132-138. [PMID: 28500869 DOI: 10.1016/j.conb.2017.04.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 04/07/2017] [Accepted: 04/20/2017] [Indexed: 12/13/2022]
Abstract
Daily, animals need to decide when to stop engaging in cognitive processes and behavioral responses to the environment, and go to sleep. The main processes regulating the daily organization of sleep and wakefulness are circadian rhythms and homeostatic sleep pressure. In addition, motivational processes such as food seeking and predator evasion can modulate sleep/wake behaviors. Here, we discuss the principal processes regulating the propensity to stay awake or go to sleep-focusing on neuronal and behavioral aspects. We first introduce the neuronal populations involved in sleep/wake regulation. Next, we describe the circadian and homeostatic drives for sleep. Then, we highlight studies demonstrating various effects of motivational processes on sleep/wake behaviors, and discuss possible neuronal mechanisms underlying their control.
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Affiliation(s)
- Ada Eban-Rothschild
- Department of Psychiatry and Behavioral Sciences, Stanford University, 1201 Welch Road, Stanford, CA 94305, USA.
| | - William J Giardino
- Department of Psychiatry and Behavioral Sciences, Stanford University, 1201 Welch Road, Stanford, CA 94305, USA
| | - Luis de Lecea
- Department of Psychiatry and Behavioral Sciences, Stanford University, 1201 Welch Road, Stanford, CA 94305, USA.
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435
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Chen Z, Wilson MA. Deciphering Neural Codes of Memory during Sleep. Trends Neurosci 2017; 40:260-275. [PMID: 28390699 PMCID: PMC5434457 DOI: 10.1016/j.tins.2017.03.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 03/13/2017] [Accepted: 03/14/2017] [Indexed: 02/07/2023]
Abstract
Memories of experiences are stored in the cerebral cortex. Sleep is critical for the consolidation of hippocampal memory of wake experiences into the neocortex. Understanding representations of neural codes of hippocampal-neocortical networks during sleep would reveal important circuit mechanisms in memory consolidation and provide novel insights into memory and dreams. Although sleep-associated ensemble spike activity has been investigated, identifying the content of memory in sleep remains challenging. Here we revisit important experimental findings on sleep-associated memory (i.e., neural activity patterns in sleep that reflect memory processing) and review computational approaches to the analysis of sleep-associated neural codes (SANCs). We focus on two analysis paradigms for sleep-associated memory and propose a new unsupervised learning framework ('memory first, meaning later') for unbiased assessment of SANCs.
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Affiliation(s)
- Zhe Chen
- Department of Psychiatry, Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY 10016, USA.
| | - Matthew A Wilson
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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436
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Shimaoka D, Song C, Knöpfel T. State-Dependent Modulation of Slow Wave Motifs towards Awakening. Front Cell Neurosci 2017; 11:108. [PMID: 28484371 PMCID: PMC5401891 DOI: 10.3389/fncel.2017.00108] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 03/30/2017] [Indexed: 11/23/2022] Open
Abstract
Slow cortical waves that propagate across the cerebral cortex forming large-scale spatiotemporal propagation patterns are a hallmark of non-REM sleep and anesthesia, but also occur during resting wakefulness. To investigate how the spatial temporal properties of slow waves change with the depth of anesthetic, we optically imaged population voltage transients generated by mouse layer 2/3 pyramidal neurons across one or two cortical hemispheres dorsally with a genetically encoded voltage indicator (GEVI). From deep barbiturate anesthesia to light barbiturate sedation, depolarizing wave events recruiting at least 50% of the imaged cortical area consistently appeared as a conserved repertoire of distinct wave motifs. Toward awakening, the incidence of individual motifs changed systematically (the motif propagating from visual to motor areas increased while that from somatosensory to visual areas decreased) and both local and global cortical dynamics accelerated. These findings highlight that functional endogenous interactions between distant cortical areas are not only constrained by anatomical connectivity, but can also be modulated by the brain state.
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Affiliation(s)
- Daisuke Shimaoka
- Neuroinformatics Japan Center (DS), RIKEN Brain Science InstituteSaitama, Japan.,Institute of Ophthalmology, University College LondonLondon, UK
| | - Chenchen Song
- Laboratory for Neuronal Circuit Dynamics, Imperial College LondonLondon, UK
| | - Thomas Knöpfel
- Neuroinformatics Japan Center (DS), RIKEN Brain Science InstituteSaitama, Japan.,Institute of Ophthalmology, University College LondonLondon, UK.,Laboratory for Neuronal Circuit Dynamics, Imperial College LondonLondon, UK.,Centre for Neurotechnology, Institute of Biomedical Engineering, Imperial College LondonLondon, UK
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437
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Vyazovskiy VV, Palchykova S, Achermann P, Tobler I, Deboer T. Different Effects of Sleep Deprivation and Torpor on EEG Slow-Wave Characteristics in Djungarian Hamsters. Cereb Cortex 2017; 27:950-961. [PMID: 28168294 PMCID: PMC5390404 DOI: 10.1093/cercor/bhx020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Indexed: 12/21/2022] Open
Abstract
It has been shown previously in Djungarian hamsters that the initial electroencephalography (EEG) slow-wave activity (power in the 0.5–4.0 Hz band; SWA) in non-rapid eye movement (NREM) sleep following an episode of daily torpor is consistently enhanced, similar to the SWA increase after sleep deprivation (SD). However, it is unknown whether the network mechanisms underlying the SWA increase after torpor and SD are similar. EEG slow waves recorded in the neocortex during sleep reflect synchronized transitions between periods of activity and silence among large neuronal populations. We therefore set out to investigate characteristics of individual cortical EEG slow waves recorded during NREM sleep after 4 h SD and during sleep after emergence from an episode of daily torpor in adult male Djungarian hamsters. We found that during the first hour after both SD and torpor, the SWA increase was associated with an increase in slow-wave incidence and amplitude. However, the slopes of single slow waves during NREM sleep were steeper in the first hour after SD but not after torpor, and, in contrast to sleep after SD, the magnitude of change in slopes after torpor was unrelated to the changes in SWA. Furthermore, slow-wave slopes decreased progressively within the first 2 h after SD, while a progressive increase in slow-wave slopes was apparent during the first 2 h after torpor. The data suggest that prolonged waking and torpor have different effects on cortical network activity underlying slow-wave characteristics, while resulting in a similar homeostatic sleep response of SWA. We suggest that sleep plays an important role in network homeostasis after both waking and torpor, consistent with a recovery function for both states.
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Affiliation(s)
- V V Vyazovskiy
- Department of Physiology, Anatomy and Genetics, University of Oxford, OX1 3PT Oxford, UK
| | | | - P Achermann
- Institute of Pharmacology and Toxicology, University of Zurich, CH-8057 Zurich, Switzerland
| | - I Tobler
- Institute of Pharmacology and Toxicology, University of Zurich, CH-8057 Zurich, Switzerland
| | - T Deboer
- Laboratory for Neurophysiology, Department of Molecular Cell Biology, Leiden University Medical Center, LUMC S-05-P, PO Box 9600, 2300 RC Leiden, the Netherlands
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438
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Kanda T, Ohyama K, Muramoto H, Kitajima N, Sekiya H. Promising techniques to illuminate neuromodulatory control of the cerebral cortex in sleeping and waking states. Neurosci Res 2017; 118:92-103. [PMID: 28434992 DOI: 10.1016/j.neures.2017.04.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 03/27/2017] [Accepted: 04/05/2017] [Indexed: 01/31/2023]
Abstract
Sleep, a common event in daily life, has clear benefits for brain function, but what goes on in the brain when we sleep remains unclear. Sleep was long regarded as a silent state of the brain because the brain seemingly lacks interaction with the surroundings during sleep. Since the discovery of electrical activities in the brain at rest, electrophysiological methods have revealed novel concepts in sleep research. During sleep, the brain generates oscillatory activities that represent characteristic states of sleep. In addition to electrophysiology, opto/chemogenetics and two-photon Ca2+ imaging methods have clarified that the sleep/wake states organized by neuronal and glial ensembles in the cerebral cortex are transitioned by neuromodulators. Even with these methods, however, it is extremely difficult to elucidate how and when neuromodulators spread, accumulate, and disappear in the extracellular space of the cortex. Thus, real-time monitoring of neuromodulator dynamics at high spatiotemporal resolution is required for further understanding of sleep. Toward direct detection of neuromodulator behavior during sleep and wakefulness, in this review, we discuss developing imaging techniques based on the activation of G-protein-coupled receptors that allow for visualization of neuromodulator dynamics.
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Affiliation(s)
- Takeshi Kanda
- International Institute for Integrative Sleep Medicine, University of Tsukuba, Ibaraki 305-8575, Japan.
| | - Kaoru Ohyama
- International Institute for Integrative Sleep Medicine, University of Tsukuba, Ibaraki 305-8575, Japan
| | - Hiroki Muramoto
- International Institute for Integrative Sleep Medicine, University of Tsukuba, Ibaraki 305-8575, Japan
| | - Nami Kitajima
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Bunkyo, Tokyo 113-0033, Japan
| | - Hiroshi Sekiya
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Bunkyo, Tokyo 113-0033, Japan.
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439
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Abstract
Consciousness never fades during wake. However, if awakened from sleep, sometimes we report dreams and sometimes no experiences. Traditionally, dreaming has been identified with REM sleep, characterized by a wake-like, globally ‘activated’, high-frequency EEG. However, dreaming also occurs in NREM sleep, characterized by prominent low-frequency activity. This challenges our understanding of the neural correlates of conscious experiences in sleep. Using high-density EEG, we contrasted the presence and absence of dreaming within NREM and REM sleep. In both NREM and REM sleep, reports of dream experience were associated with a local decrease in low-frequency activity in posterior cortical regions. High-frequency activity within these regions correlated with specific dream contents. Monitoring this posterior ‘hot zone’ predicted whether an individual reported dreaming or the absence of experiences during NREM sleep in real time, suggesting that it may constitute a core correlate of conscious experiences in sleep.
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440
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Batterink LJ, Paller KA. Sleep-based memory processing facilitates grammatical generalization: Evidence from targeted memory reactivation. BRAIN AND LANGUAGE 2017; 167:83-93. [PMID: 26443322 PMCID: PMC4819015 DOI: 10.1016/j.bandl.2015.09.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 08/20/2015] [Accepted: 09/01/2015] [Indexed: 06/05/2023]
Abstract
Generalization-the ability to abstract regularities from specific examples and apply them to novel instances-is an essential component of language acquisition. Generalization not only depends on exposure to input during wake, but may also improve offline during sleep. Here we examined whether targeted memory reactivation during sleep can influence grammatical generalization. Participants gradually acquired the grammatical rules of an artificial language through an interactive learning procedure. Then, phrases from the language (experimental group) or stimuli from an unrelated task (control group) were covertly presented during an afternoon nap. Compared to control participants, participants re-exposed to the language during sleep showed larger gains in grammatical generalization. Sleep cues produced a bias, not necessarily a pure gain, suggesting that the capacity for memory replay during sleep is limited. We conclude that grammatical generalization was biased by auditory cueing during sleep, and by extension, that sleep likely influences grammatical generalization in general.
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Affiliation(s)
- Laura J Batterink
- Northwestern University, Department of Psychology, 2029 Sheridan Road, Evanston, IL 60208-2710, USA.
| | - Ken A Paller
- Northwestern University, Department of Psychology, 2029 Sheridan Road, Evanston, IL 60208-2710, USA
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441
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Kremen V, Duque JJ, Brinkmann BH, Berry BM, Kucewicz MT, Khadjevand F, Van Gompel J, Stead M, St Louis EK, Worrell GA. Behavioral state classification in epileptic brain using intracranial electrophysiology. J Neural Eng 2017; 14:026001. [PMID: 28050973 PMCID: PMC5460075 DOI: 10.1088/1741-2552/aa5688] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE Automated behavioral state classification can benefit next generation implantable epilepsy devices. In this study we explored the feasibility of automated awake (AW) and slow wave sleep (SWS) classification using wide bandwidth intracranial EEG (iEEG) in patients undergoing evaluation for epilepsy surgery. APPROACH Data from seven patients (age [Formula: see text], 4 women) who underwent intracranial depth electrode implantation for iEEG monitoring were included. Spectral power features (0.1-600 Hz) spanning several frequency bands from a single electrode were used to train and test a support vector machine classifier. MAIN RESULTS Classification accuracy of 97.8 ± 0.3% (normal tissue) and 89.4 ± 0.8% (epileptic tissue) across seven subjects using multiple spectral power features from a single electrode was achieved. Spectral power features from electrodes placed in normal temporal neocortex were found to be more useful (accuracy 90.8 ± 0.8%) for sleep-wake state classification than electrodes located in normal hippocampus (87.1 ± 1.6%). Spectral power in high frequency band features (Ripple (80-250 Hz), Fast Ripple (250-600 Hz)) showed comparable performance for AW and SWS classification as the best performing Berger bands (Alpha, Beta, low Gamma) with accuracy ⩾90% using a single electrode contact and single spectral feature. SIGNIFICANCE Automated classification of wake and SWS should prove useful for future implantable epilepsy devices with limited computational power, memory, and number of electrodes. Applications include quantifying patient sleep patterns and behavioral state dependent detection, prediction, and electrical stimulation therapies.
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Affiliation(s)
- Vaclav Kremen
- Department of Neurology, Mayo Systems Electrophysiology Laboratory, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA. Czech Institute of Informatics, Robotics and Cybernetics, Czech Technical University in Prague, Zikova street 1903/4, 166 36 Prague 6, Czech Republic. Department of Physiology and Biomedical Engineering, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA
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442
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Schmitt K, Grimm A, Eckert A. Amyloid-β-Induced Changes in Molecular Clock Properties and Cellular Bioenergetics. Front Neurosci 2017; 11:124. [PMID: 28367108 PMCID: PMC5355433 DOI: 10.3389/fnins.2017.00124] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 02/28/2017] [Indexed: 11/20/2022] Open
Abstract
Ageing is an inevitable biological process that results in a progressive structural and functional decline, as well as biochemical alterations that altogether lead to reduced ability to adapt to environmental changes. As clock oscillations and clock-controlled rhythms are not resilient to the aging process, aging of the circadian system may also increase susceptibility to age-related pathologies such as Alzheimer's disease (AD). Besides the amyloid-beta protein (Aβ)-induced metabolic decline and neuronal toxicity in AD, numerous studies have demonstrated that the disruption of sleep and circadian rhythms is one of the common and earliest signs of the disease. In this study, we addressed the questions of whether Aβ contributes to an abnormal molecular circadian clock leading to a bioenergetic imbalance. For this purpose, we used different oscillator cellular models: human skin fibroblasts, human glioma cells, as well as mouse primary cortical and hippocampal neurons. We first evaluated the circadian period length, a molecular clock property, in the presence of different Aβ species. We report here that physiologically relevant Aβ1–42 concentrations ranging from 10 to 500 nM induced an increase of the period length in human skin fibroblasts, human A172 glioma cells as well as in mouse primary neurons whereas the reverse control peptide Aβ42-1, which is devoid of toxic action, did not influence the circadian period length within the same concentration range. To better understand the underlying mechanisms that are involved in the Aβ-related alterations of the circadian clock, we examined the cellular metabolic state in the human primary skin fibroblast model. Notably, under normal conditions, ATP levels displayed circadian oscillations, which correspond to the respective circadian pattern of mitochondrial respiration. In contrast, Aβ1–42 treatment provoked a strong dampening in the metabolic oscillations of ATP levels as well as mitochondrial respiration and in addition, induced an increased oxidized state. Overall, we gain here new insights into the deleterious cycle involved in Aβ-induced decay of the circadian rhythms leading to metabolic deficits, which may contribute to the failure in mitochondrial energy metabolism associated with the pathogenesis of AD.
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Affiliation(s)
- Karen Schmitt
- Neurobiology Lab for Brain Aging and Mental Health, Transfaculty Research Platform, Molecular and Cognitive Neuroscience, University of BaselBasel, Switzerland; Psychiatric University Clinics, University of BaselBasel, Switzerland
| | - Amandine Grimm
- Neurobiology Lab for Brain Aging and Mental Health, Transfaculty Research Platform, Molecular and Cognitive Neuroscience, University of BaselBasel, Switzerland; Psychiatric University Clinics, University of BaselBasel, Switzerland
| | - Anne Eckert
- Neurobiology Lab for Brain Aging and Mental Health, Transfaculty Research Platform, Molecular and Cognitive Neuroscience, University of BaselBasel, Switzerland; Psychiatric University Clinics, University of BaselBasel, Switzerland
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443
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Giret N, Edeline JM, Del Negro C. Neural mechanisms of vocal imitation: The role of sleep replay in shaping mirror neurons. Neurosci Biobehav Rev 2017; 77:58-73. [PMID: 28288397 DOI: 10.1016/j.neubiorev.2017.01.051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 01/04/2017] [Accepted: 01/04/2017] [Indexed: 01/19/2023]
Abstract
Learning by imitation involves not only perceiving another individual's action to copy it, but also the formation of a memory trace in order to gradually establish a correspondence between the sensory and motor codes, which represent this action through sensorimotor experience. Memory and sensorimotor processes are closely intertwined. Mirror neurons, which fire both when the same action is performed or perceived, have received considerable attention in the context of imitation. An influential view of memory processes considers that the consolidation of newly acquired information or skills involves an active offline reprocessing of memories during sleep within the neuronal networks that were initially used for encoding. Here, we review the recent advances in the field of mirror neurons and offline processes in the songbird. We further propose a theoretical framework that could establish the neurobiological foundations of sensorimotor learning by imitation. We propose that the reactivation of neuronal assemblies during offline periods contributes to the integration of sensory feedback information and the establishment of sensorimotor mirroring activity at the neuronal level.
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Affiliation(s)
- Nicolas Giret
- Neuroscience Paris-Saclay Institute, CNRS, Université Paris Sud, Université Paris Saclay, Orsay, France.
| | - Jean-Marc Edeline
- Neuroscience Paris-Saclay Institute, CNRS, Université Paris Sud, Université Paris Saclay, Orsay, France.
| | - Catherine Del Negro
- Neuroscience Paris-Saclay Institute, CNRS, Université Paris Sud, Université Paris Saclay, Orsay, France.
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444
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Papalambros NA, Santostasi G, Malkani RG, Braun R, Weintraub S, Paller KA, Zee PC. Acoustic Enhancement of Sleep Slow Oscillations and Concomitant Memory Improvement in Older Adults. Front Hum Neurosci 2017; 11:109. [PMID: 28337134 PMCID: PMC5340797 DOI: 10.3389/fnhum.2017.00109] [Citation(s) in RCA: 160] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 02/21/2017] [Indexed: 11/16/2022] Open
Abstract
Acoustic stimulation methods applied during sleep in young adults can increase slow wave activity (SWA) and improve sleep-dependent memory retention. It is unknown whether this approach enhances SWA and memory in older adults, who generally have reduced SWA compared to younger adults. Additionally, older adults are at risk for age-related cognitive impairment and therefore may benefit from non-invasive interventions. The aim of this study was to determine if acoustic stimulation can increase SWA and improve declarative memory in healthy older adults. Thirteen participants 60–84 years old completed one night of acoustic stimulation and one night of sham stimulation in random order. During sleep, a real-time algorithm using an adaptive phase-locked loop modeled the phase of endogenous slow waves in midline frontopolar electroencephalographic recordings. Pulses of pink noise were delivered when the upstate of the slow wave was predicted. Each interval of five pulses (“ON interval”) was followed by a pause of approximately equal length (“OFF interval”). SWA during the entire sleep period was similar between stimulation and sham conditions, whereas SWA and spindle activity were increased during ON intervals compared to matched periods during the sham night. The increases in SWA and spindle activity were sustained across almost the entire five-pulse ON interval compared to matched sham periods. Verbal paired-associate memory was tested before and after sleep. Overnight improvement in word recall was significantly greater with acoustic stimulation compared to sham and was correlated with changes in SWA between ON and OFF intervals. Using the phase-locked-loop method to precisely target acoustic stimulation to the upstate of sleep slow oscillations, we were able to enhance SWA and improve sleep-dependent memory storage in older adults, which strengthens the theoretical link between sleep and age-related memory integrity.
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Affiliation(s)
- Nelly A Papalambros
- Center for Circadian and Sleep Medicine, Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago IL, USA
| | - Giovanni Santostasi
- Center for Circadian and Sleep Medicine, Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago IL, USA
| | - Roneil G Malkani
- Center for Circadian and Sleep Medicine, Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago IL, USA
| | - Rosemary Braun
- Biostatistics Division, Feinberg School of Medicine, Northwestern University, ChicagoIL, USA; Department of Engineering Sciences and Applied Mathematics, Northwestern University, EvanstonIL, USA
| | - Sandra Weintraub
- Cognitive Neurology and Alzheimer's Disease Center and Department of Psychiatry and Behavioral Sciences, Northwestern University, Chicago IL, USA
| | - Ken A Paller
- Department of Psychology, Northwestern University, Evanston IL, USA
| | - Phyllis C Zee
- Center for Circadian and Sleep Medicine, Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago IL, USA
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445
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Eban-Rothschild A, de Lecea L. Neuronal substrates for initiation, maintenance, and structural organization of sleep/wake states. F1000Res 2017; 6:212. [PMID: 28357049 PMCID: PMC5345773 DOI: 10.12688/f1000research.9677.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/20/2017] [Indexed: 11/20/2022] Open
Abstract
Animals continuously alternate between sleep and wake states throughout their life. The daily organization of sleep and wakefulness is orchestrated by circadian, homeostatic, and motivational processes. Over the last decades, much progress has been made toward determining the neuronal populations involved in sleep/wake regulation. Here, we will discuss how the application of advanced
in vivo tools for cell type–specific manipulations now permits the functional interrogation of different features of sleep/wake state regulation: initiation, maintenance, and structural organization. We will specifically focus on recent studies examining the roles of wake-promoting neuronal populations.
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Affiliation(s)
- Ada Eban-Rothschild
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, 94305, USA
| | - Luis de Lecea
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, 94305, USA
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446
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Panagiotou M, Vyazovskiy VV, Meijer JH, Deboer T. Differences in electroencephalographic non-rapid-eye movement sleep slow-wave characteristics between young and old mice. Sci Rep 2017; 7:43656. [PMID: 28255162 PMCID: PMC5334640 DOI: 10.1038/srep43656] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 01/25/2017] [Indexed: 01/22/2023] Open
Abstract
Changes in sleep pattern are typical for the normal aging process. However, aged mice show an increase in the amount of sleep, whereas humans show a decrease when aging. Mice are considered an important model in aging studies, and this divergence warrants further investigation. Recently, insights into the network dynamics of cortical activity during sleep were obtained by investigating characteristics of individual electroencephalogram (EEG) slow waves in young and elderly humans. In this study, we investigated, for the first time, the parameters of EEG slow waves, including their incidence, amplitude, duration and slopes, in young (6 months) and older (18-24 months) C57BL/6J mice during undisturbed 24 h, and after a 6-h sleep deprivation (SD). As expected, older mice slept more but, in contrast to humans, absolute NREM sleep EEG slow-wave activity (SWA, spectral power density between 0.5-4 Hz) was higher in the older mice, as compared to the young controls. Furthermore, slow waves in the older mice were characterized by increased amplitude, steeper slopes and fewer multipeak waves, indicating increased synchronization of cortical neurons in aging, opposite to what was found in humans. Our results suggest that older mice, in contrast to elderly humans, live under a high sleep pressure.
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Affiliation(s)
- Maria Panagiotou
- Laboratory for Neurophysiology, Department of Molecular Cell Biology, Leiden University Medical Centre, 2333 ZC Leiden, The Netherlands
| | - Vladyslav V Vyazovskiy
- Department of Physiology, Anatomy and Genetics, University of Oxford, OX1 3PT Oxford, UK
| | - Johanna H Meijer
- Laboratory for Neurophysiology, Department of Molecular Cell Biology, Leiden University Medical Centre, 2333 ZC Leiden, The Netherlands
| | - Tom Deboer
- Laboratory for Neurophysiology, Department of Molecular Cell Biology, Leiden University Medical Centre, 2333 ZC Leiden, The Netherlands
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447
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Bódizs R, Gombos F, Ujma PP, Szakadát S, Sándor P, Simor P, Pótári A, Konrad BN, Genzel L, Steiger A, Dresler M, Kovács I. The hemispheric lateralization of sleep spindles in humans. ACTA ACUST UNITED AC 2017. [DOI: 10.1556/2053.01.2017.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Róbert Bódizs
- Institute of Behavioural Sciences, Semmelweis University, Budapest, Hungary
- Department of General Psychology, Pázmány Péter Catholic University, Budapest, Hungary
- National Institute of Clinical Neurosciences, Budapest, Hungary
| | - Ferenc Gombos
- Department of General Psychology, Pázmány Péter Catholic University, Budapest, Hungary
| | - Péter P. Ujma
- Institute of Behavioural Sciences, Semmelweis University, Budapest, Hungary
- National Institute of Clinical Neurosciences, Budapest, Hungary
| | - Sára Szakadát
- Institute of Behavioural Sciences, Semmelweis University, Budapest, Hungary
| | - Piroska Sándor
- Institute of Behavioural Sciences, Semmelweis University, Budapest, Hungary
| | - Péter Simor
- Department of Cognitive Science, Budapest University of Technology and Economics, Budapest, Hungary
- Nyírő Gyula Hospital, National Institute of Psychiatry and Addictions, Budapest, Hungary
| | - Adrián Pótári
- Department of Cognitive Science, Budapest University of Technology and Economics, Budapest, Hungary
| | | | - Lisa Genzel
- Centre for Cognitive and Neural Systems, University of Edinburgh, Edinburgh, United Kingdom
| | - Axel Steiger
- Max Planck Institute of Psychiatry, Munich, Germany
| | - Martin Dresler
- Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
- Max Planck Institute of Psychiatry, Munich, Germany
| | - Ilona Kovács
- Department of General Psychology, Pázmány Péter Catholic University, Budapest, Hungary
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448
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Sharon O, Nir Y. Attenuated Fast Steady-State Visual Evoked Potentials During Human Sleep. Cereb Cortex 2017; 28:1297-1311. [DOI: 10.1093/cercor/bhx043] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Indexed: 12/30/2022] Open
Affiliation(s)
- Omer Sharon
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yuval Nir
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
- Functional Neurophysiology and Sleep Research Lab, Tel-Aviv Sourasky Medical Center, Tel Aviv, Israel
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449
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Automated selective disruption of slow wave sleep. J Neurosci Methods 2017; 281:33-39. [PMID: 28238859 DOI: 10.1016/j.jneumeth.2017.02.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 01/29/2017] [Accepted: 02/21/2017] [Indexed: 11/23/2022]
Abstract
BACKGROUND Slow wave sleep (SWS) plays an important role in neurophysiologic restoration. Experimentally testing the effect of SWS disruption previously required highly time-intensive and subjective methods. Our goal was to develop an automated and objective protocol to reduce SWS without affecting sleep architecture. NEW METHOD We developed a custom Matlab™ protocol to calculate electroencephalogram spectral power every 10s live during a polysomnogram, exclude artifact, and, if measurements met criteria for SWS, deliver increasingly louder tones through earphones. Middle-aged healthy volunteers (n=10) each underwent 2 polysomnograms, one with the SWS disruption protocol and one with sham condition. RESULTS The SWS disruption protocol reduced SWS compared to sham condition, as measured by spectral power in the delta (0.5-4Hz) band, particularly in the 0.5-2Hz range (mean 20% decrease). A compensatory increase in the proportion of total spectral power in the theta (4-8Hz) and alpha (8-12Hz) bands was seen, but otherwise normal sleep features were preserved. N3 sleep decreased from 20±34 to 3±6min, otherwise there were no significant changes in total sleep time, sleep efficiency, or other macrostructural sleep characteristics. COMPARISON WITH EXISTING METHOD This novel SWS disruption protocol produces specific reductions in delta band power similar to existing methods, but has the advantage of being automated, such that SWS disruption can be performed easily in a highly standardized and operator-independent manner. CONCLUSION This automated SWS disruption protocol effectively reduces SWS without impacting overall sleep architecture.
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450
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Zhang F, Zhong R, Li S, Chang RCC, Le W. The missing link between sleep disorders and age-related dementia: recent evidence and plausible mechanisms. J Neural Transm (Vienna) 2017; 124:559-568. [PMID: 28188439 DOI: 10.1007/s00702-017-1696-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 12/30/2016] [Indexed: 12/14/2022]
Abstract
Sleep disorders are among the most common clinical problems and possess a significant concern for the geriatric population. More importantly, while around 40% of elderly adults have sleep-related complaints, sleep disorders are more frequently associated with co-morbidities including age-related neurodegenerative diseases and mild cognitive impairment. Recently, increasing evidence has indicated that disturbed sleep may not only serve as the consequence of brain atrophy, but also contribute to the pathogenesis of dementia and, therefore, significantly increase dementia risk. Since the current therapeutic interventions lack efficacies to prevent, delay or reverse the pathological progress of dementia, a better understanding of underlying mechanisms by which sleep disorders interact with the pathogenesis of dementia will provide possible targets for the prevention and treatment of dementia. In this review, we briefly describe the physiological roles of sleep in learning/memory, and specifically update the recent research evidence demonstrating the association between sleep disorders and dementia. Plausible mechanisms are further discussed. Moreover, we also evaluate the possibility of sleep therapy as a potential intervention for dementia.
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Affiliation(s)
- Feng Zhang
- Liaoning Provincial Clinical Research Center for Neurological Diseases, The First Affiliated Hospital, Dalian Medical University, Dalian, 116021, China.,Liaoning Provincial Key Laboratory for Research on the Pathogenic Mechanisms of Neurological Diseases, The First Affiliated Hospital, Dalian Medical University, Dalian, 116021, China
| | - Rujia Zhong
- Liaoning Provincial Clinical Research Center for Neurological Diseases, The First Affiliated Hospital, Dalian Medical University, Dalian, 116021, China.,Liaoning Provincial Key Laboratory for Research on the Pathogenic Mechanisms of Neurological Diseases, The First Affiliated Hospital, Dalian Medical University, Dalian, 116021, China
| | - Song Li
- Liaoning Provincial Clinical Research Center for Neurological Diseases, The First Affiliated Hospital, Dalian Medical University, Dalian, 116021, China.,Liaoning Provincial Key Laboratory for Research on the Pathogenic Mechanisms of Neurological Diseases, The First Affiliated Hospital, Dalian Medical University, Dalian, 116021, China
| | - Raymond Chuen-Chung Chang
- Laboratory of Neurodegenerative Diseases, LKS Faculty of Medicine, School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Weidong Le
- Liaoning Provincial Clinical Research Center for Neurological Diseases, The First Affiliated Hospital, Dalian Medical University, Dalian, 116021, China. .,Liaoning Provincial Key Laboratory for Research on the Pathogenic Mechanisms of Neurological Diseases, The First Affiliated Hospital, Dalian Medical University, Dalian, 116021, China. .,Collaborative Innovation Center for Brain Science, The First Affiliated Hospital, Dalian Medical University, Dalian, 116011, China.
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