Ghrelin promotes slow-wave sleep in humans

Ghrelin, an endogenous ligand of the growth hormone (GH) secretagogue (GHS) receptor, stimulates GH release, appetite, and weight gain in humans and rodents. Synthetic GHSs modulate sleep electroencephalogram (EEG) and nocturnal hormone secretion. We studied the effect of 4 × 50 μg of ghrelin administered hourly as intravenous boluses between 2200 and 0100 on sleep EEG and the secretion of plasma GH, ACTH, cortisol, prolactin, and leptin in humans ( n = 7). After ghrelin administration, slow-wave sleep was increased during the total night and accumulated δ-wave activity was enhanced during the second half of the night. Rapid-eye-movement (REM) sleep was reduced during the second third of the night, whereas all other sleep EEG variables remained unchanged. Furthermore, GH and prolactin plasma levels were enhanced throughout the night, and cortisol levels increased during the first part of the night (2200–0300). The response of GH to ghrelin was most distinct after the first injection and lowest after the fourth injection. In contrast, cortisol showed an inverse pattern of response. Leptin levels did not differ between groups. Our data show a distinct action of exogenous ghrelin on sleep EEG and nocturnal hormone secretion. We suggest that ghrelin is an endogenous sleep-promoting factor. This role appears to be complementary to the already described effects of the peptide in the regulation of energy balance. Furthermore, ghrelin appears to be a common stimulus of the somatotropic and hypothalamo-pituitary-adrenocortical systems. It appears that ghrelin is a sleep-promoting factor in humans.

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A pilot study on essential oil aroma stimulation for enhancing slow-wave EEG in sleeping brain

Scientific Reports ◽

10.1038/s41598-020-80171-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Li-Wei Ko ◽

Cheng-Hua Su ◽

Meng-Hsun Yang ◽

Shen-Yi Liu ◽

Tung-Ping Su

Keyword(s):

Essential Oil ◽

Sleep Quality ◽

Slow Wave ◽

Slow Wave Sleep ◽

Sleep Eeg ◽

Poor Sleep ◽

Alpha Power ◽

Poor Sleep Quality ◽

Healthy Human ◽

Study Results

AbstractSleep quality is important to health and life quality. Lack of sleep can lead to a variety of health issues and reduce in daytime function. Recent study by Fultz et al. also indicated that sleep is crucial to brain metabolism. Delta power in sleep EEG often indicates good sleep quality while alpha power usually indicates sleep interruptions and poor sleep quality. Essential oil has been speculated to improve sleep quality. Previous studies also suggest essential oil aroma may affect human brain activity when applied awake. However, those studies were often not blinded, which makes the effectiveness and mechanism of aroma a heavily debated topic. In this study, we aim to explore the effect of essential oil aroma on human sleep quality and sleep EEG in a single-blinded setup. The aroma was released when the participants are asleep, which kept the influence of psychological expectation to the minimum. We recruited nine young, healthy participants with regular lifestyle and no sleep problem. All participants reported better sleep quality and more daytime vigorous after exposing to lavender aroma in sleep. We also observed that upon lavender aroma releases, alpha wave in wake stage was reduced while delta wave in slow-wave sleep (SWS) was increased. Lastly, we found that lavender oil promote occurrence of SWS. Overall, our study results show that essential oil aroma can be used to promote both subjective and objective sleep quality in healthy human subjects. This makes aroma intervention a potential solution for poor sleep quality and insomnia.

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Spike-wave seizures, slow-wave sleep EEG and morphology of substantia nigra pars compacta in WAG/Rij rats with genetic predisposition to absence epilepsy

Brain Research Bulletin ◽

10.1016/j.brainresbull.2021.06.003 ◽

2021 ◽

Author(s):

Evgenia Sitnikova ◽

Elizaveta M. Rutskova ◽

Daria Tsvetaeva ◽

Vladimir V. Raevsky

Keyword(s):

Substantia Nigra ◽

Slow Wave ◽

Genetic Predisposition ◽

Slow Wave Sleep ◽

Absence Epilepsy ◽

Sleep Eeg ◽

Substantia Nigra Pars Compacta ◽

Spike Wave

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EEG delta power and auditory arousal in rested and sleep-deprived rabbits

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1997.272.2.r648 ◽

1997 ◽

Vol 272 (2) ◽

pp. R648-R655 ◽

Cited By ~ 4

Author(s):

M. R. Opp ◽

L. A. Toth ◽

E. A. Tolley

Keyword(s):

Slow Wave ◽

Slow Wave Sleep ◽

Rabbit Model ◽

Stimulus Presentation ◽

Wave Activity ◽

Slow Wave Activity ◽

Auditory Stimuli ◽

Delta Power ◽

Postural Changes ◽

Behavioral Responsiveness

Slow-wave activity in the electroencephalogram is thought to reflect the depth or intensity of sleep. This hypothesis is primarily derived from studies of rats or humans. However, some characteristics of sleep of rabbits differ from those of rats or humans. To determine whether slow-wave activity (power density in the delta frequency band of 0.5-5.0 Hz) correlates with arousability in rabbits, we presented auditory stimuli (72-90 dB) to control or sleep-deprived animals during slow-wave sleep. The resulting behavioral responses, defined by changes in eye state and body posture, and the latency to return to sleep were used as measures of arousability. Behavioral responsiveness to auditory stimuli increased with increasing stimulus intensity in both control and sleep-deprived animals. Overall, however, sleep-deprived animals exhibited fewer postural changes and eye openings than did control rabbits. Sleep-deprived rabbits also more rapidly returned to sleep after the stimulus presentation than did control animals. Latency to return to sleep was correlated with delta power before stimulus presentation, but behavioral responsiveness was not. These data suggest that, in this rabbit model, delta power may not be predictive of behavioral arousability but may reflect sleep propensity.

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Continuous Spike-and-Wave Activity during Slow-Wave Sleep

Pediatric Epilepsy Case Studies ◽

10.1201/b13612-38 ◽

2008 ◽

pp. 243-250

Keyword(s):

Slow Wave ◽

Slow Wave Sleep ◽

Wave Activity

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nCPAP Treatment of Obstructive Sleep Apnea Increases Slow Wave Sleep in Prefrontal EEG

Clinical EEG and Neuroscience ◽

10.1177/155005940703800311 ◽

2007 ◽

Vol 38 (3) ◽

pp. 148-154 ◽

Cited By ~ 4

Author(s):

Veera Eskelinen ◽

Toomas Uibu ◽

Sari-Leena Himanen

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Treatment Period ◽

Slow Wave ◽

Slow Wave Sleep ◽

Sleep Stage ◽

Sleep Eeg ◽

Sleep Stages ◽

Obstructive Sleep ◽

Sleep Stage Scoring

According to standard sleep stage scoring, sleep EEG is studied from the central area of parietal lobes. However, slow wave sleep (SWS) has been found to be more powerful in frontal areas in healthy subjects. Obstructive sleep apnea syndrome (OSAS) patients often suffer from functional disturbances in prefrontal lobes. We studied the effects of nasal Continuous Positive Airway Pressure (nCPAP) treatment on sleep EEG, and especially on SWS, in left prefrontal and central locations in 12 mild to moderate OSAS patients. Sleep EEG was recorded by polysomnography before treatment and after a 3 month nCPAP treatment period. Recordings were classified into sleep stages. No difference was found in SWS by central sleep stage scoring after the nCPAP treatment period, but in the prefrontal lobe all night S3 sleep stage increased during treatment. Furthermore, prefrontal SWS increased in the second and decreased in the fourth NREM period. There was more SWS in prefrontal areas both before and after nCPAP treatment, and SWS increased significantly more in prefrontal than central areas during treatment. Regarding only central sleep stage scoring, nCPAP treatment did not increase SWS significantly. Frontopolar recording of sleep EEG is useful in addition to central recordings in order to better evaluate the results of nCPAP treatment.

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Interleukin-1 derived from astrocytes enhances slow wave activity in sleep EEG of the rat

European Journal of Pharmacology ◽

10.1016/0014-2999(84)90391-1 ◽

1984 ◽

Vol 104 (1-2) ◽

pp. 191-192 ◽

Cited By ~ 120

Author(s):

Irene Tobler ◽

Alexander A. Borbély ◽

Martin Schwyzer ◽

Adriano Fontana

Keyword(s):

Slow Wave ◽

Interleukin 1 ◽

Wave Activity ◽

Slow Wave Activity ◽

Sleep Eeg

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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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Hypersynchronous Delta Sleep EEG Activity and Sudden Arousals from Slow-Wave Sleep in Adults Without a History of Parasomnias: Clinical and Forensic Implications

SLEEP ◽

10.1093/sleep/27.4.706 ◽

2004 ◽

Vol 27 (4) ◽

pp. 706-710 ◽

Cited By ~ 50

Author(s):

Mark R. Pressman

Keyword(s):

Slow Wave ◽

Slow Wave Sleep ◽

Sleep Eeg ◽

Eeg Activity ◽

History Of ◽

Delta Sleep ◽

Forensic Implications

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Scalp EEG interictal high frequency oscillations as an objective EEG biomarker of infantile spasms

10.1101/2020.05.31.126573 ◽

2020 ◽

Author(s):

Hiroki Nariai ◽

Shaun A. Hussain ◽

Danilo Bernardo ◽

Hirotaka Motoi ◽

Masaki Sonoda ◽

...

Keyword(s):

Slow Wave ◽

High Frequency ◽

Slow Wave Sleep ◽

Wave Activity ◽

Infantile Spasms ◽

Slow Wave Activity ◽

List Type ◽

Normal Children ◽

High Frequency Oscillations ◽

Epileptic Spasms

ABSTRACTObjectiveTo investigate the diagnostic utility of high frequency oscillations (HFOs) via scalp electroencephalogram (EEG) in infantile spasms.MethodsWe retrospectively analyzed interictal slow-wave sleep EEGs sampled at 2,000 Hz recorded from 30 consecutive patients who were suspected of having infantile spasms. We measured the rate of HFOs (80-500 Hz) and the strength of the cross-frequency coupling between HFOs and slow-wave activity (SWA) at 3-4 Hz and 0.5-1 Hz as quantified with modulation indices (MIs).ResultsTwenty-three patients (77%) exhibited active spasms during the overnight EEG recording. Although the HFOs were detected in all children, increased HFO rate and MIs correlated with the presence of active spasms (p < 0.001 by HFO rate; p < 0.01 by MIs at 3-4 Hz; p = 0.02 by MIs at 0.5-1 Hz). The presence of active spasms was predicted by the logistic regression models incorporating HFO-related metrics (AUC: 0.80-0.98) better than that incorporating hypsarrhythmia (AUC: 0.61). The predictive performance of the best model remained favorable (87.5% accuracy) after a cross-validation procedure.ConclusionsIncreased rate of HFOs and coupling between HFOs and SWA are associated with active epileptic spasms.SignificanceScalp-recorded HFOs may serve as an objective EEG biomarker for active epileptic spasms.HighlightsObjective analyses of scalp high frequency oscillations and its coupling with slow-wave activity in infantile spasms were feasible.Increased rate of high frequency oscillations and its coupling with slow-wave activity correlated with active epileptic spasms.The scalp high frequency oscillations were also detected in neurologically normal children (although at the low rate).

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