The Investigation of K-Complex and Vertex Sharp Wave Activity in Response to Mid-Inspiratory Occlusions and Complete Obstructions to Breathing During NREM Sleep

Electroencephalographic slow-wave activity (SWA) in non-rapid eye movement (NREM) sleep is directly related to prior sleep/wake history, with high levels of SWA following extended periods of wake. Therefore, SWA has been thought to reflect the level of accumulated sleep need. The discovery that euthermic intervals between hibernation bouts are spent primarily in sleep and that this sleep is characterized by high and monotonically declining SWA has led to speculation that sleep homeostasis may play a fundamental role in the regulation of the timing of bouts of hibernation and periodic arousals to euthermia. It was proposed that because the SWA profile seen after arousal from hibernation is strikingly similar to what is seen in nonhibernating mammals after extended periods of wakefulness, that hibernating mammals may arouse from hibernation with significant accumulated sleep need. This sleep need may accumulate during hibernation because the low brain temperatures during hibernation may not be compatible with sleep restorative processes. In the present study, golden-mantled ground squirrels were sleep deprived during the first 4 h of interbout euthermia by injection of caffeine (20 mg/kg ip). We predicted that if the SWA peaks after bouts of hibernation reflected a homeostatic response to an accumulated sleep need, sleep deprivation should simply have displaced and possibly augmented the SWA to subsequent recovery sleep. Instead we found that after caffeine-induced sleep deprivation of animals just aroused from hibernation, the anticipated high SWA typical of recovery sleep did not occur. Similar results were found in a study that induced sleep deprivation by gentle handling (19). These findings indicate that the SWA peak immediately after hibernation does not represent homeostatic regulation of NREM sleep, as it normally does after prolonged wakefulness during euthermia, but instead may reflect some other neurological process in the recovery of brain function from an extended period at low temperature.

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K-complexes and slow wave activity during nrem sleep in patients with Alzheimer's disease

Sleep Medicine ◽

10.1016/j.sleep.2017.11.337 ◽

2017 ◽

Vol 40 ◽

pp. e115-e116

Author(s):

M. Gorgoni ◽

F. Reda ◽

G. Lauri ◽

I. Truglia ◽

S. Cordone ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Slow Wave ◽

Nrem Sleep ◽

Wave Activity ◽

Slow Wave Activity

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Loss of circadian organization of sleep and wakefulness during hibernation

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00771.2000 ◽

2002 ◽

Vol 282 (4) ◽

pp. R1086-R1095 ◽

Cited By ~ 22

Author(s):

Jennie E. Larkin ◽

Paul Franken ◽

H. Craig Heller

Keyword(s):

Brain Temperature ◽

Nrem Sleep ◽

Wave Activity ◽

Ground Squirrels ◽

Ultradian Rhythm ◽

Organization Of Sleep ◽

Sleep Homeostasis ◽

Circadian Organization ◽

Frequency Components ◽

Torpor Bouts

We investigated circadian and homeostatic regulation of nonrapid eye movement (NREM) sleep in golden-mantled ground squirrels during euthermic intervals between torpor bouts. Slow-wave activity (SWA; 1–4 Hz) and sigma activity (10–15 Hz) represent the two dominant electroencephalographic (EEG) frequency components of NREM sleep. EEG sigma activity has a strong circadian component in addition to a sleep homeostatic component, whereas SWA mainly reflects sleep homeostasis [Dijk DJ and Czeisler CA. J Neurosci 15: 3526–3538, 1995; Dijk DJ, Shanahan TL, Duffy JF, Ronda JM, and Czeisler CA. J Physiol (Lond) 505: 851–858, 1997]. Animals maintained under constant conditions continued to display circadian rhythms in both sigma activity and brain temperature throughout euthermic intervals, whereas sleep and wakefulness showed no circadian organization. Instead, sleep and wakefulness were distributed according to a 6-h ultradian rhythm. SWA, NREM sleep bout length, and sigma activity responded homeostatically to the ultradian sleep-wake pattern. We suggest that the loss of sleep-wake consolidation in ground squirrels during the hibernation season may be related to the greatly decreased locomotor activity during the hibernation season and may be necessary for maintenance of multiday torpor bouts characteristic of hibernating species.

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Enhanced Dendritic Action Potential Backpropagation in Parvalbumin-positive Basket Cells During Sharp Wave Activity

Neurochemical Research ◽

10.1007/s11064-010-0290-4 ◽

2010 ◽

Vol 35 (12) ◽

pp. 2086-2095 ◽

Cited By ~ 6

Author(s):

Balázs Chiovini ◽

Gergely F. Turi ◽

Gergely Katona ◽

Attila Kaszás ◽

Ferenc Erdélyi ◽

...

Keyword(s):

Action Potential ◽

Wave Activity ◽

Basket Cells ◽

Sharp Wave

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Bidirectional Interaction of Hippocampal Ripples and Cortical Slow Waves Leads to Coordinated Spiking Activity During NREM Sleep

Cerebral Cortex ◽

10.1093/cercor/bhaa228 ◽

2020 ◽

Vol 31 (1) ◽

pp. 324-340

Author(s):

Pavel Sanda ◽

Paola Malerba ◽

Xi Jiang ◽

Giri P Krishnan ◽

Jorge Gonzalez-Martinez ◽

...

Keyword(s):

Slow Wave ◽

Memory Consolidation ◽

Slow Wave Sleep ◽

Nrem Sleep ◽

Slow Waves ◽

Slow Oscillation ◽

Cortical Input ◽

Sharp Wave ◽

Up States ◽

Intracranial Recordings

Abstract The dialogue between cortex and hippocampus is known to be crucial for sleep-dependent memory consolidation. During slow wave sleep, memory replay depends on slow oscillation (SO) and spindles in the (neo)cortex and sharp wave-ripples (SWRs) in the hippocampus. The mechanisms underlying interaction of these rhythms are poorly understood. We examined the interaction between cortical SO and hippocampal SWRs in a model of the hippocampo–cortico–thalamic network and compared the results with human intracranial recordings during sleep. We observed that ripple occurrence peaked following the onset of an Up-state of SO and that cortical input to hippocampus was crucial to maintain this relationship. A small fraction of ripples occurred during the Down-state and controlled initiation of the next Up-state. We observed that the effect of ripple depends on its precise timing, which supports the idea that ripples occurring at different phases of SO might serve different functions, particularly in the context of encoding the new and reactivation of the old memories during memory consolidation. The study revealed complex bidirectional interaction of SWRs and SO in which early hippocampal ripples influence transitions to Up-state, while cortical Up-states control occurrence of the later ripples, which in turn influence transition to Down-state.

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Dynamics of Slow-Wave Activity During the NREM Sleep of Sleepwalkers and Control Subjects

SLEEP ◽

10.1093/sleep/23.6.1d ◽

2000 ◽

Vol 23 (6) ◽

pp. 1-6 ◽

Cited By ~ 98

Author(s):

Hélène Gaudreau ◽

Steve Joncas ◽

Antonio Zadra ◽

Jacques Montplaisir

Keyword(s):

Slow Wave ◽

Nrem Sleep ◽

Wave Activity ◽

Slow Wave Activity ◽

Control Subjects ◽

And Control

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Age-related changes in slow wave activity rise time and NREM sleep EEG with and without zolpidem in healthy young and older adults

Sleep Medicine ◽

10.1016/j.sleep.2014.05.007 ◽

2014 ◽

Vol 15 (9) ◽

pp. 1037-1045 ◽

Cited By ~ 14

Author(s):

Evan D. Chinoy ◽

Danielle J. Frey ◽

Daniel N. Kaslovsky ◽

Francois G. Meyer ◽

Kenneth P. Wright

Keyword(s):

Older Adults ◽

Slow Wave ◽

Rise Time ◽

Nrem Sleep ◽

Wave Activity ◽

Slow Wave Activity ◽

Sleep Eeg ◽

Age Related ◽

Age Related Changes

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Relationship of sleep homeostasis to seizures and cognition in children with focal epilepsy

10.1101/2020.11.05.20226514 ◽

2020 ◽

Author(s):

Maria H Eriksson ◽

Torsten Baldeweg ◽

Ronit Pressler ◽

Stewart G Boyd ◽

Reto Huber ◽

...

Keyword(s):

Slow Wave ◽

Focal Epilepsy ◽

Nrem Sleep ◽

Wave Activity ◽

Slow Wave Activity ◽

Iq Testing ◽

Sleep Homeostasis ◽

Interictal Discharges ◽

Relationship Of ◽

The Relationship

AbstractObjectiveSleep disruption and cognitive impairment are important co-morbidities in childhood epilepsy, yet a mechanistic link has not been substantiated. Slow wave activity during sleep and its homeostatic decrease across the night is associated with synaptic renormalisation, and shows maturational changes over the course of childhood. Here, we aimed to investigate the effect of epilepsy on sleep homeostasis in the developing brain.MethodsWe examined the relationship of sleep homeostasis as reflected in slow wave activity to seizures, cognition and behaviour, comparing 22 children (aged 6 to 16 years) with focal epilepsy to 21 age-matched healthy controls. Participants underwent overnight sleep EEG and IQ testing and performed memory consolidation tasks. Their parents completed standard behavioural questionnaires.ResultsChildren with epilepsy had lower slow wave activity at the start of non-rapid eye movement (NREM) sleep, though similar overnight decline and slow wave activity in the final hour of NREM sleep. Both groups displayed an antero-posterior shift in peak slow wave activity overnight, though individual patients showed persistent local increases at scalp locations matching those of focal interictal discharges. Patients who had seizures during their admission had lower early-night slow wave activity, the group without seizures showing similar activity to controls. We found a positive correlation between full scale IQ and early-night slow wave activity in patients but not controls.InterpretationReduced early night slow wave activity in children with focal epilepsies is correlated with lower cognitive ability and more seizures and may reflect a reduction in learning-related synaptic potentiation.

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Local Targeted Memory Reactivation in Human Sleep

10.1101/539114 ◽

2019 ◽

Cited By ~ 1

Author(s):

Ella Bar ◽

Anat Arzi ◽

Ofer Perl ◽

Ethan Livne ◽

Noam Sobel ◽

...

Keyword(s):

Slow Wave ◽

Visual Fields ◽

Nrem Sleep ◽

Wave Activity ◽

Functional Neuroanatomy ◽

Memory Reactivation ◽

Odor Cues ◽

Human Sleep ◽

Global Action ◽

Local Sleep

AbstractMemory consolidation can be promoted via Targeted Memory Reactivation (TMR) that re-presents training cues or context during sleep. Whether TMR acts locally or globally on cortical sleep oscillations remains unknown. Here we exploit the unique functional neuroanatomy of olfaction with its ipsilateral stimulus processing to perform local TMR in one brain hemisphere. Participants learned associations between words and locations in left or right visual fields with contextual odor throughout. During post-learning naps, odors were presented to one nostril throughout NREM sleep. We found improved memory for specific words processed in the cued hemisphere (ipsilateral to stimulated nostril). Unilateral odor cues locally modulated slow wave activity (SWA) such that regional SWA increase in the cued hemisphere negatively correlated with select memories for cued words. Moreover, local TMR improved slow wave-spindle coupling specifically in the cued hemisphere. Thus, TMR in human sleep transcends global action by selectively promoting specific memories associated with local sleep oscillations.

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