scholarly journals Don't count your chickens before they're hatched: Elaborative encoding in REM dreaming in face of the physiology of sleep stages

2013 ◽  
Vol 36 (6) ◽  
pp. 613-614
Author(s):  
Gaétane Deliens ◽  
Sophie Schwartz ◽  
Philippe Peigneux
Keyword(s):  
Eye Movement ◽  
Rem Sleep ◽  
De Novo ◽  
Nrem Sleep ◽  
Sleep Stages ◽  
Rapid Eye Movement ◽  
Hidden Patterns ◽  
Episodic Memories ◽  
Novel Associations

AbstractLlewellyn suggests that episodic memories undergo “elaborative encoding” during rapid eye movement (REM) dreams, generating novel associations between recent and remote memories that are then instantiated during non-REM (NREM) sleep. This hypothesis conflicts with our knowledge of the physiology of NREM and then REM sleep stages and their ordered succession. Moreover, associations during sleep might also involve the extraction of hidden patterns rather than de novo associations.

scholarly journals Contribution of REM sleep and N2 sleep spindles to procedural memory consolidation in Vipassana meditators and non-meditating controls.

2017 ◽  
Author(s):  
Elizaveta Solomonova ◽  
Simon Dubé ◽  
Cloé Blanchette-Carrière ◽  
Arnaud Samson-Richer ◽  
Michelle Carr ◽  
...  
Keyword(s):  
Eye Movement ◽  
Rem Sleep ◽  
Memory Consolidation ◽  
Nrem Sleep ◽  
Procedural Memory ◽  
Sleep Stages ◽  
Sleep Spindles ◽  
Meditation Practice ◽  
Rapid Eye Movement ◽  
Vipassana Meditation

Study objectives: Rapid eye movement (REM) sleep, non-rapid eye movement (NREM) sleep, and sleep spindles are all implicated in the consolidation of procedural memories. The relative contributions of sleep stages and sleep spindles was previously shown to depend on individual differences in task processing. Experience with Vipassana meditation is one such individual difference that has not been investigated in relation to sleep. Vipassana meditation is a form of mental training that enhances proprioceptive and somatic awareness and alters attentional style. The goal was thus to examine a potential moderating role for Vipassana meditation experience on sleep-dependent procedural memory consolidation.Methods: Groups of Vipassana meditation practitioners (N=20) and matched meditation-naïve controls (N=20) slept for a single daytime nap in the laboratory. Before and after the nap they completed a procedural task on the Wii Fit balance platform.Results: Meditators performed slightly better on the task before the nap, but the two groups improved similarly after sleep. The groups showed different patterns of sleep-dependent procedural memory consolidation: in meditators task learning was negatively correlated with density of fast and positively correlated with density of slow occipital spindles, while in controls task improvement was associated with increases in REM sleep. Meditation practitioners had a lower density of sleep spindles, especially in occipital regions.Conclusions: Results suggest that neuroplastic changes associated with sustained meditation practice may alter overall sleep architecture and reorganize sleep-dependent patterns of memory consolidation. The lower density of spindles in meditators may mean that meditation practice compensates for some of the memory functions of sleep.

Altered heart rate variability during sleep in mild cognitive impairment

SLEEP ◽  
2020 ◽  
Author(s):  
Shawn D X Kong ◽  
Camilla M Hoyos ◽  
Craig L Phillips ◽  
Andrew C McKinnon ◽  
Pinghsiu Lin ◽  
...  
Keyword(s):  
Older Adults ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Eye Movement ◽  
Rem Sleep ◽  
Nrem Sleep ◽  
Sleep Stages ◽  
Rapid Eye Movement

Abstract Study Objectives Cardiovascular autonomic dysfunction, as measured by short-term diurnal heart rate variability (HRV), has been reported in older adults with mild cognitive impairment (MCI). However, it is unclear whether this impairment also exists during sleep in this group. We, therefore, compared overnight HRV during sleep in older adults with MCI and those with subjective cognitive impairment (SCI). Methods Older adults (n = 210) underwent overnight polysomnography. Eligible participants were characterized as multi-domain MCI or SCI. The multi-domain MCI group was comprised of amnestic and non-amnestic subtypes. Power spectral analysis of HRV was conducted on the overnight electrocardiogram during non-rapid eye movement (NREM), rapid eye movement (REM), N1, N2, N3 sleep stages, and wake periods. High-frequency HRV (HF-HRV) was employed as the primary measure to estimate parasympathetic function. Results The MCI group showed reduced HF-HRV during NREM sleep (p = 0.018), but not during wake or REM sleep (p > 0.05) compared to the SCI group. Participants with aMCI compared to SCI had the most pronounced reduction in HF-HRV across all NREM sleep stages—N1, N2, and N3, but not during wake or REM sleep. The naMCI sub-group did not show any significant differences in HF-HRV during any sleep stage compared to SCI. Conclusions Our study showed that amnestic MCI participants had greater reductions in HF-HRV during NREM sleep, relative to those with SCI, suggesting potential vulnerability to sleep-related parasympathetic dysfunction. HF-HRV, especially during NREM sleep, may be an early biomarker for dementia detection.

Development of Sleep-Wake Patterns and Non-rapid Eye Movement Sleep Stages during the First Six Months of Life in Normal Infants

PEDIATRICS ◽  
1982 ◽  
Vol 69 (6) ◽  
pp. 793-798
Author(s):  
Susan Coons ◽  
Christian Guilleminault
Keyword(s):  
Eye Movement ◽  
Rem Sleep ◽  
Early Period ◽  
Nrem Sleep ◽  
Distribution Patterns ◽  
Reciprocal Relationship ◽  
Sleep Stages ◽  
Rapid Eye Movement ◽  
Wake Patterns ◽  
Qualitative Changes

Thirty-one normal infants were selected for 24-hour polygraphic monitoring at different ages during the first six months of life. The development of sleep-wake distribution patterns during day and night was observed. Qualitative changes in non-rapid eye movement (NREM) sleep as it becomes differentiated in stages 1, 2, and 3-4 were measured. Sustained periods of wake are present by 6 weeks of age. After 3 months of age, wake is predictably distributed in late afternoon and early evening. REM sleep is disproportionately distributed within sleep in 24 hours, presenting a higher percent of total sleep during the night. At 4.5 and 6 months of age, stages 2 and 3-4 NREM are coincident during the nocturnal hours and 3-4 NREM sleep peaks in the early period of the night. The decreasing proportion of REM sleep, particularly in its daytime distribution, suggests a reciprocal relationship to the development of wakefulness.

Hemodynamic changes associated with obstructive sleep apnea followed by arousal in a porcine model

1993 ◽  
Vol 75 (4) ◽  
pp. 1439-1443 ◽  
Author(s):  
J. M. Pinto ◽  
E. Garpestad ◽  
J. W. Weiss ◽  
D. M. Bergau ◽  
D. A. Kirby
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Eye Movement ◽  
Coronary Blood Flow ◽  
Rem Sleep ◽  
Resistance Index ◽  
Nrem Sleep ◽  
Sleep Stages ◽  
Rapid Eye Movement ◽  
Obstructive Sleep

To study the effects of airway obstruction (AWO) and arousal on coronary blood flow, mean arterial pressure (MAP), and heart rate, pigs were chronically instrumented with arterial catheters, Doppler flow probes on the left circumflex coronary artery, and electrodes for determination of sleep stages. A modified tracheostomy tube was placed in the trachea to obstruct the upper airway during sleep sessions. In control studies, during non-rapid-eye-movement (NREM) sleep, MAP was 84 +/- 2 mmHg before AWO and increased by 5 +/- 2 mmHg on arousal. MAP was lower during rapid-eye-movement (REM) sleep (62 +/- 2 mmHg), and the increase on arousal was fourfold greater (22 +/- 2 mmHg). Heart rate was similar in both sleep stages (NREM: 120 +/- 4 beats/min; REM: 124 +/- 5 beats/min) and increased significantly on arousal (NREM: 12 +/- 2 beats/min; REM: 18 +/- 1 beats/min). Coronary blood flow was similar during both stages (NREM: 43 +/- 4 ml/min; REM: 46 +/- 8 ml/min) and increased by 12–15% on arousal. Coronary vascular resistance index increased significantly by 24% on arousal from AWO during REM sleep. All increases and decreases were significant at P < 0.05. Receptor blockade studies were performed to assess alpha-adrenergic receptor involvement.

scholarly journals POLYSOMNOGRAPHY

JMS SKIMS ◽  
2015 ◽  
Vol 18 (2) ◽  
pp. 165-166
Author(s):  
Juhi Jamwal ◽  
Suhail Malik
Keyword(s):  
Sleep Disorders ◽  
Eye Movement ◽  
Rem Sleep ◽  
Ph Monitoring ◽  
Body Position ◽  
Nrem Sleep ◽  
Response To Treatment ◽  
Sleep Stages ◽  
Normal Person ◽  
Rapid Eye Movement

Polysomnography (PSG) is the gold standard diagnostic test for several sleep disorders. It records , analyzes, & interprets multiple simultaneous physiologic characteristics during sleep. These parameters include brain waves, the oxygen level in the blood, heart rate and breathing, body position, as well as eye and leg movements, along with synchronized audiovisual monitoring. Moreover, in certain conditions, additional parameters may be included such as esophageal pH monitoring, esophageal manometry , and overnight blood pressure monitoring. The test is usually performed at a sleep disorders unit within a hospital or at a sleep disorders centre. Sleep architecture is largely divided into non-rapid eye movement (NREM) and rapid eye movement (REM) sleep. NREM is further divided into three stages: N1, N2, and N3 : N3 being the deepest stage of sleep. REM sleep alternates with NREM sleep and a normal person usually has 4–6 cycles of REM and NREM sleep . Monitoring of the different sleep stages, sleep interruptions, movements, and the other respiratory and cardiac signals are clinically helpful for identifying the nature of patient’s sleep problems and assessing response to treatment. JMS 2015;18(2):165-166

Sleep Disorders

2015 ◽  
Author(s):  
Sudhansu Chokroverty
Keyword(s):  
Sleep Apnea ◽  
Sleep Disorders ◽  
Eye Movement ◽  
Rem Sleep ◽  
Sleep Apnea Syndrome ◽  
Nrem Sleep ◽  
Rapid Eye Movement ◽  
Circadian Rhythm Sleep Disorders ◽  
Apnea Syndrome ◽  
Sleep Mechanism

Recent research has generated an enormous fund of knowledge about the neurobiology of sleep and wakefulness. Sleeping and waking brain circuits can now be studied by sophisticated neuroimaging techniques that map different areas of the brain during different sleep states and stages. Although the exact biologic functions of sleep are not known, sleep is essential, and sleep deprivation leads to impaired attention and decreased performance. Sleep is also believed to have restorative, conservative, adaptive, thermoregulatory, and consolidative functions. This review discusses the physiology of sleep, including its two independent states, rapid eye movement (REM) and non–rapid eye movement (NREM) sleep, as well as functional neuroanatomy, physiologic changes during sleep, and circadian rhythms. The classification and diagnosis of sleep disorders are discussed generally. The diagnosis and treatment of the following disorders are described: obstructive sleep apnea syndrome, narcolepsy-cataplexy sydrome, idiopathic hypersomnia, restless legs syndrome (RLS) and periodic limb movements in sleep, circadian rhythm sleep disorders, insomnias, nocturnal frontal lobe epilepsy, and parasomnias. Sleep-related movement disorders and the relationship between sleep and psychiatric disorders are also discussed. Tables describe behavioral and physiologic characteristics of states of awareness, the international classification of sleep disorders, common sleep complaints, comorbid insomnia disorders, causes of excessive daytime somnolence, laboratory tests to assess sleep disorders, essential diagnostic criteria for RLS and Willis-Ekbom disease, and drug therapy for insomnia. Figures include polysomnographic recording showing wakefulness in an adult; stage 1, 2, and 3 NREM sleep in an adult; REM sleep in an adult; a patient with sleep apnea syndrome; a patient with Cheyne-Stokes breathing; a patient with RLS; and a patient with dream-enacting behavior; schematic sagittal section of the brainstem of the cat; schematic diagram of the McCarley-Hobson model of REM sleep mechanism; the Lu-Saper “flip-flop” model; the Luppi model to explain REM sleep mechanism; and a wrist actigraph from a man with bipolar disorder. This review contains 14 highly rendered figures, 8 tables, 115 references, and 5 MCQs.

Sleep Disorders

2015 ◽  
Author(s):  
Sudhansu Chokroverty
Keyword(s):  
Sleep Apnea ◽  
Sleep Disorders ◽  
Eye Movement ◽  
Rem Sleep ◽  
Sleep Apnea Syndrome ◽  
Nrem Sleep ◽  
Rapid Eye Movement ◽  
Circadian Rhythm Sleep Disorders ◽  
Apnea Syndrome ◽  
Sleep Mechanism

Recent research has generated an enormous fund of knowledge about the neurobiology of sleep and wakefulness. Sleeping and waking brain circuits can now be studied by sophisticated neuroimaging techniques that map different areas of the brain during different sleep states and stages. Although the exact biologic functions of sleep are not known, sleep is essential, and sleep deprivation leads to impaired attention and decreased performance. Sleep is also believed to have restorative, conservative, adaptive, thermoregulatory, and consolidative functions. This review discusses the physiology of sleep, including its two independent states, rapid eye movement (REM) and non–rapid eye movement (NREM) sleep, as well as functional neuroanatomy, physiologic changes during sleep, and circadian rhythms. The classification and diagnosis of sleep disorders are discussed generally. The diagnosis and treatment of the following disorders are described: obstructive sleep apnea syndrome, narcolepsy-cataplexy sydrome, idiopathic hypersomnia, restless legs syndrome (RLS) and periodic limb movements in sleep, circadian rhythm sleep disorders, insomnias, nocturnal frontal lobe epilepsy, and parasomnias. Sleep-related movement disorders and the relationship between sleep and psychiatric disorders are also discussed. Tables describe behavioral and physiologic characteristics of states of awareness, the international classification of sleep disorders, common sleep complaints, comorbid insomnia disorders, causes of excessive daytime somnolence, laboratory tests to assess sleep disorders, essential diagnostic criteria for RLS and Willis-Ekbom disease, and drug therapy for insomnia. Figures include polysomnographic recording showing wakefulness in an adult; stage 1, 2, and 3 NREM sleep in an adult; REM sleep in an adult; a patient with sleep apnea syndrome; a patient with Cheyne-Stokes breathing; a patient with RLS; and a patient with dream-enacting behavior; schematic sagittal section of the brainstem of the cat; schematic diagram of the McCarley-Hobson model of REM sleep mechanism; the Lu-Saper “flip-flop” model; the Luppi model to explain REM sleep mechanism; and a wrist actigraph from a man with bipolar disorder. This review contains 14 highly rendered figures, 8 tables, 115 references, and 5 MCQs.

Arousal Characteristics in Patients with Parkinson’s Disease and Isolated Rapid Eye Movement Sleep Behavior Disorder

SLEEP ◽  
2021 ◽  
Author(s):  
Andreas Brink-Kjær ◽  
Matteo Cesari ◽  
Friederike Sixel-Döring ◽  
Brit Mollenhauer ◽  
Claudia Trenkwalder ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Eye Movement ◽  
Rem Sleep ◽  
Regression Models ◽  
Muscle Tone ◽  
Behavior Disorder ◽  
Nrem Sleep ◽  
Rapid Eye Movement ◽  
Sleep Behavior

Abstract Study objectives Patients diagnosed with isolated rapid eye movement (REM) sleep behavior disorder (iRBD) and Parkinson’s disease (PD) have altered sleep stability reflecting neurodegeneration in brainstem structures. We hypothesize that neurodegeneration alters the expression of cortical arousals in sleep. Methods We analyzed polysomnography data recorded from 88 healthy controls (HC), 22 iRBD patients, 82 de novo PD patients without RBD and 32 with RBD (PD+RBD). These patients were also investigated at a 2-year follow-up. Arousals were analyzed using a previously validated automatic system, which used a central EEG lead, electrooculography, and chin electromyography. Multiple linear regression models were fitted to compare group differences at baseline and change to follow-up for arousal index (ArI), shifts in electroencephalographic signals associated with arousals, and arousal chin muscle tone. The regression models were adjusted for known covariates affecting the nature of arousal. Results In comparison to HC, patients with iRBD and PD+RBD showed increased ArI during REM sleep and their arousals showed a significantly lower shift in α-band power at arousals and a higher muscle tone during arousals. In comparison to HC, the PD patients were characterized by a decreased ArI in NREM sleep at baseline. ArI during NREM sleep decreased further at the 2-year follow-up, although not significantly Conclusions Patients with PD and iRBD present with abnormal arousal characteristics as scored by an automated method. These abnormalities are likely to be caused by neurodegeneration of the reticular activation system due to alpha-synuclein aggregation.

Abstract P417: Relationship Between Blood Pressure Variability and Sleep Architecture

Circulation ◽  
2020 ◽  
Vol 141 (Suppl_1) ◽  
Author(s):  
Xiaoyue Liu ◽  
Jeongok G Logan ◽  
Younghoon Kwon ◽  
Jennifer Lobo ◽  
Hyojung Kang ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Eye Movement ◽  
Rem Sleep ◽  
Sleep Time ◽  
Sleep Architecture ◽  
Sleep Stages ◽  
Apnea Hypopnea Index ◽  
Rapid Eye Movement ◽  
Sleep Studies ◽  
The Relationship

Introduction: Blood pressure (BP) variability (BPV) is a novel marker for cardiovascular disease (CVD) independent of high BP. Sleep architecture represents the structured pattern of sleep stages consisting of rapid eye movement (REM) and non-rapid eye movement (NREM), and it is an important element in the homeostatic regulation of sleep. Currently, little is known regarding whether BPV is linked to sleep stages. Our study aimed to examine the relationship between sleep architecture and BPV. Methods: We analyzed in-lab polysomnographic studies collected from individuals who underwent diagnostic sleep studies at a university hospital from 2010 to 2017. BP measures obtained during one year prior to the sleep studies were included. BPV was computed using the coefficient of variation for all individuals who had three or more systolic and diastolic BP data. We conducted linear regression analysis to assess the relationship of systolic BPV (SBPV) and diastolic BPV (DBPV) with the sleep stage distribution (REM and NREM sleep time), respectively. Covariates that can potentially confound the relationships were adjusted in the models, including age, sex, race/ethnicity, body mass index, total sleep time, apnea-hypopnea index, mean BP, and history of medication use (antipsychotics, antidepressants, and antihypertensives) during the past two years before the sleep studies. Results: Our sample (N=3,565; male = 1,353) was racially and ethnically diverse, with a mean age 54 ± 15 years and a mean BP of 131/76 ± 13.9/8.4 mmHg. Among the sleep architecture measures examined, SBPV showed an inverse relationship with REM sleep time after controlling for all covariates ( p = .033). We subsequently categorized SBPV into four quartiles and found that the 3 rd quartile (mean SBP SD = 14.9 ± 2.1 mmHg) had 3.3 fewer minutes in REM sleep compared to the 1 st quartile ( p = .02). However, we did not observe any relationship between DBPV and sleep architecture. Conclusion: Greater SBPV was associated with lower REM sleep time. This finding suggests a possible interplay between BPV and sleep architecture. Future investigation is warranted to clarify the directionality, mechanism, and therapeutic implications.

scholarly journals Nonrapid eye movement sleep electroencephalographic oscillations in idiopathic rapid eye movement sleep behavior disorder: a study of sleep spindles and slow oscillations

SLEEP ◽  
2020 ◽  
Author(s):  
Jun-Sang Sunwoo ◽  
Kwang Su Cha ◽  
Jung-Ick Byun ◽  
Jin-Sun Jun ◽  
Tae-Joon Kim ◽  
...  
Keyword(s):  
Eye Movement ◽  
Rem Sleep ◽  
Rem Sleep Behavior Disorder ◽  
Behavior Disorder ◽  
Nrem Sleep ◽  
Sleep Spindles ◽  
Rapid Eye Movement ◽  
Sleep Behavior ◽  
Slow Oscillations ◽  
Lower Amplitude

Abstract Study Objectives We investigated electroencephalographic (EEG) slow oscillations (SOs), sleep spindles (SSs), and their temporal coordination during nonrapid eye movement (NREM) sleep in patients with idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD). Methods We analyzed 16 patients with video-polysomnography-confirmed iRBD (age, 65.4 ± 6.6 years; male, 87.5%) and 10 controls (age, 62.3 ± 7.5 years; male, 70%). SSs and SOs were automatically detected during stage N2 and N3. We analyzed their characteristics, including density, frequency, duration, and amplitude. We additionally identified SO-locked spindles and examined their phase distribution and phase locking with the corresponding SO. For inter-group comparisons, we used the independent samples t-test or Wilcoxon rank-sum test, as appropriate. Results The SOs of iRBD patients had significantly lower amplitude, longer duration (p = 0.005 for both), and shallower slope (p &lt; 0.001) than those of controls. The SS power of iRBD patients was significantly lower than that of controls (p = 0.002), although spindle density did not differ significantly. Furthermore, SO-locked spindles of iRBD patients prematurely occurred during the down-to-up-state transition of SOs, whereas those of controls occurred at the up-state peak of SOs (p = 0.009). The phase of SO-locked spindles showed a positive correlation with delayed recall subscores (p = 0.005) but not with tonic or phasic electromyography activity during REM sleep. Conclusions In this study, we found abnormal EEG oscillations during NREM sleep in patients with iRBD. The impaired temporal coupling between SOs and SSs may reflect early neurodegenerative changes in iRBD.

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