• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.201-202
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• 1998

In this paper we suggested an automated method for detecting and counting rapid eye movement(REM) using EOG during sleep. This method is formulated by two step fuzzy logic. At first step, the velocity and the distance of single channel eye movement are used for the fuzzy input to get the possibility of being REM at each EOG. At second step, the two possibility values of both EOG from the first step and the correlation coefficient of both eye movements are used for the fuzzy logic input, and the output is the final possibility of being Rapid Eye Movement. We applied this algorithm to the normal and narcoleptic sleep data and compared the difference. We found the possibility that the count of REM can be a parameter that has significant physiological meanings.

• Journal of Oral Medicine and Pain
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• v.41 no.4
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• pp.180-187
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• 2016

Purpose: The aims of this study were to evaluate the differences of clinical and polysomnographic features between rapid eye movement (REM)-related obstructive sleep apnea (OSA) and not-REM-related OSA, and to suggest the pathogenesis according to the REM dependency of OSA. Methods: One hundred ninety consecutive patients diagnosed with OSA were evaluated clinical features and performed full night polysomnography. The patients were divided into REM-related (REM apnea-hypopnea index [AHI] at least two times higher than their non-REM AHI) and not-REM-related (a REM AHI less than two times higher than their non-REM AHI) OSA groups and evaluated the differences in age, body mass index (BMI), neck circumference, Ep-worth Sleepiness Scale score, and parameters of polysomnography. Results: REM-related patients were younger and showed higher sleep efficacy, low percentage of light sleep stage (stage 1 sleep), and low rate of positional OSA. Age was significantly associated with REM dependency of OSA and REM AHI were significant correlated with BMI, neck circumference, percentage of sleep in supine position, and percentage time of snoring. Conclusions: Our results showed that REM-related OSA patients showed less severe polysomnographic parameters than not-REM-related patients. However, significant risk factors were differed depending on the REM dependency and OSA severity, and the clinical features correlated with REM AHI and non-REM AHI were also showed differently. We suggest that the occurrence of OSA according to the REM dependency can be based on different mechanisms.

• Natural Product Sciences
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• v.15 no.4
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• pp.213-221
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• 2009

Longanae Arillus (the rind of fruits of Dimocarpus longan) has been consumed for the treatment of insomnia and anxiety in Asia. To provide further scientific basis to traditional uses of this fruit on insomnia, we evaluated the effects of methanol extract of Longanae Arillus (MELA) on the alteration of sleep architecture and electroencephalogram (EEG) power spectra in acutely and chronically restraint-stressed rats. Following postsurgical recovery, Polygraphic signs of sleep-wake activities were recorded for 24 h after MELA administration in rats. Rats in the acute stress and chronic stress were administered with MELA for 10 days. On the $8^{th},\;9^{th}\;and\;10^{th}$ day of MELA administration, the rats were stressed for 3 h once per day. On the $10^{th}$ day and 1 h after MELA administration, the rats were stressed once for 22 h in the chronic stress group. Acute and chronic stress induced alternations in cortex EEG recordings during non-rapid eye movement (NREM), rapid eye movement (REM) sleep and wakefulness. MELA shortened the total and REM sleep and increased the wakefulness in night time recording without changing daytime recordings. Chronic stress increased wakefulness and REM sleep, decreased total and NREM sleep in the daytime recording, and increased REM and decreased NREM sleep without changing total sleep and wakefulness in night time recording. These findings suggest that MELA ameliorated the alterations in REM and NREM sleep of acutely and chronically stressed rats via modulation of cortical ${\alpha}-$, ${\theta}-$ and ${\delta}-$ wave activity.

• Sleep Medicine and Psychophysiology
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• v.11 no.1
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• pp.10-16
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• 2004

Sleep is associated with definite changes in respiratory function in normal human beings. During sleep, there is loss of voluntary control of breathing and a decrease in the usual ventilatory response to both low oxygen and high carbon dioxide levels. Especially, rapid eye movement (REM) sleep is a distinct neurophysiological state associated with significant changes in breathing pattern and ventilatory control as compared with both wakefulness and non-rapid eye movement (NREM) sleep. REM sleep is characterized by erratic, shallow breathing with irregularities both in amplitude and frequency owing to marked reduction in intercostal and upper airway muscle activity. These blunted ventilatory responses during sleep are clinically important. They permit marked hypoxemia that occurs during REM sleep in patients with lung or chest wall disease. In addition, sleep-disordered breathing (SDB) is more frequent and longer and hypoventilation is more pronounced during REM sleep. Although apneic episodes are most frequent and severe during REM sleep, most adults spend less than 20 to 25% of total sleep time in REM sleep. It is, therefore, possible for patients to have frequent apneas and hypopneas during REM sleep and still have a normal apnea-hypopnea index if the event-rich REM periods are diluted by event-poor periods of NREM sleep. In this review, we address respiratory physiology according to sleep stage, and the clinical implications of SDB and hypoventilation aggravated during REM sleep.

• Journal of Ginseng Research
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• v.32 no.3
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• pp.220-225
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• 2008

The present investigation was performed to evaluate the homeostatic regulation of sleep architecture by the ethanol extract of Korea red ginseng (KRG), since the available data were often controversial. In addition, it was also interested in whether the sleep-wake stages were differently affected by low and high doses of KRG. Each adult Wistar male rat was implanted with a transmitter for recording EEG and activity via telemetry. After one week of surgery, polygraphic signs of undisturbed sleep-wake activities were recorded for 12 h (between 9:00 am and 9:00 pm) after KRG administration. KRG (10 and 100 mg/kg) increased non-rapid eye movement (NREM) sleep as well as total sleep. The total percentages of wakefulness were decreased comparably. KRG (10 mg/kg) decreased the power density of the ${\delta}-wave$ (0.75-4.5 Hz) and increased ${\alpha}-wave$ (8.0-13.0 Hz) in the NREM and rapid eye movement (REM) sleep. KRG also decreased ${\delta}-wave$ power density in wake time. However, KRG (100 mg/kg) increased ${\delta}-wave$ and decreased ${\theta}-wave$ (5.0-9.0 Hz) power density in wake time, while showed little effect on the power density in NREM and REM sleep. In conclusion, low and high doses of KRG increase spontaneous sleep and NREM sleep and differently regulate the EEG spectra in REM and NREM sleep.

• Journal of Oral Medicine and Pain
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• v.41 no.2
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• pp.54-60
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• 2016

Purpose: Mandibular advancement devices (MAD) are used effectively and widely for the treatment of obstructive sleep apnea (OSA) and rapid-eye-movement (REM) dependency of the patients can affect the treatment outcome of OSA. The aim of this study was to compare treatment outcomes of MAD between REM-related and not-REM-related OSA patients. Methods: Fifty-six consecutive patients with OSA who received MAD therapy were evaluated using full night polysomnography before and after insertion of the MADs. The patients were divided into REM-related (REM apnea-hypopnea index [AHI] at least two times higher than their non-REM AHI) and not-REM-related (REM AHI less than two times higher than their non-REM AHI) OSA groups. Results: MAD is used for the treatment of OSA effectively. In respect of AHI, MAD therapy were effective both in REM-related OSA and not-REM-related OSA, but MAD therapy was more effective in not-REM-related OSA than REM-related OSA in overall sleep and non-REM sleep. $SpO_2$ saturations were improved after MAD therapy, but were not different between two groups. Epworth sleepiness scale scores were not improved after MAD therapy. Percentage of REM sleep was increased after MAD therapy but was not different between two groups. Conclusions: MAD therapy was more effective in not-REM-related OSA than REM-related OSA and REM dependency can be a predictive factor of treatment outcome of oral appliance for OSA patients.

• Journal of Ginseng Research
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• v.36 no.4
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• pp.403-410
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• 2012

The current inquiry was conducted to assess the change in sleep architecture after long periods of administration to determine whether ginseng can be used in the therapy of sleeplessness. Following post-surgical recovery, red ginseng extract (RGE, 200 mg/kg) was orally administrated to rats for 9 d. Data were gathered on the 1st, 5th, and 9th day, and an electroencephalogram was recorded 24 h after RGE administration. Polygraphic signs of unobstructed sleep-wake activities were simultaneously recorded with sleep-wake recording electrodes from 11:00 a.m. to 5:00 p.m. for 6 h. Rodents were generally tamed to freely moving polygraphic recording conditions. Although the 1st and 5th day of RGE treatment showed no effect on power densities in nonrapid eye movement (NREM) and rapid eye movement (REM) sleep, the 9th day of RGE administration showed augmented ${\alpha}$-wave (8.0 to 13.0 Hz) power densities in NREM and REM sleep. RGE increased total sleep and NREM sleep. The total percentage of wakefulness was only decreased on the 9th day, and the number of sleep-wake cycles was reduced after the repeated administration of RGE. Thus, the repeated administration of RGE increased NREM sleep in rats. The ${\alpha}$-wave activities in the cortical electroencephalograms were increased in sleep architecture by RGE. Moreover, the levels of both ${\alpha}$- and ${\beta}$-subunits of the ${\gamma}$-aminobutyric acid $(GABA)_A$ receptor were reduced in the hypothalamus of the RGE-treated groups. The level of glutamic acid decarboxylase was over-expressed in the hypothalamus. These results demonstrate that RGE increases NREM sleep via $GABA_A$ergic systems.

• Journal of Ginseng Research
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• v.34 no.1
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• pp.30-40
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• 2010

The present investigation was conducted to evaluate the regulation of sleep architecture by the red ginseng water extract (RGE) in acutely and chronically restraint stressed rats. Adult rats were fitted with sleep.wake recording electrodes. Following post-surgical recovery, rats were extensively habituated for freely moving polygraphic recording conditions. Polygraphic signs of sleep-wake activities were recorded for 24 h after RGE administration and induction of stress and were analyzed to understand the regulation of sleep architecture. Acute stress decreased wakefulness and increased total sleep, non-rapid eye movement (NREM) sleep, and rapid eye movement (REM) sleep in both the daytime and nighttime recording. RGE shortened the daytime NREM and REM sleep, without changing the wakefulness and total sleep. RGE increased nighttime wakefulness, and decreased total, NREM and REM sleep. Chronic stress increased wakefulness and decreased total sleep in the daytime recording, and increased REM and decreased NREM sleep in both the day and night time recording. RGE ameliorated chronic stress and induced alterations of REM and NREM sleep in the day and night time sleep architecture. Acute and chronic stress could also induce alternations in cortex electroencephalogram (EEG) recording during NREM, REM sleep and wakefulness. These findings suggest that RGE may modulate the sleep behavior in acutely and chronically stressed rats and the ameliorating effect of RGE on the sleep architecture may involve in modulation of $\alpha$-, $\theta$- and $\delta$- wave activities of the cortical EEG.

• Biomolecules & Therapeutics
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• v.26 no.4
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• pp.368-373
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• 2018

Rapid eye movement (REM) sleep has an essential role in the process of learning and memory in the hippocampus. It has been reported that linalool, a major component of Lavandula angustifolia, has antioxidant, anti-inflammatory, and neuroprotective effects, along with other effects. However, the effect of linalool on the cognitive impairment and behavioral alterations that are induced by REM-sleep deprivation has not yet been elucidated. Several studies have reported that REM-sleep deprivation-induced memory deficits provide a well-known model of behavioral alterations. In the present study, we examined whether linalool elicited an anti-stress effect, reversing the behavioral alterations observed following REM-sleep deprivation in mice. Furthermore, we investigated the underlying mechanism of the effect of linalool. Spatial memory and learning memory were assessed through Y maze and passive avoidance tests, respectively, and the forced swimming test was used to evaluate anti-stress activity. The mechanisms through which linalool improves memory loss and behavioral alterations in sleep-deprived mice appeared to be through an increase in the serotonin levels. Linalool significantly ameliorated the spatial and learning memory deficits, and stress activity observed in sleep-deprived animals. Moreover, linalool led to serotonin release, and cortisol level reduction. Our findings suggest that linalool has beneficial effects on the memory loss and behavioral alterations induced by REM-sleep deprivation through the regulation of serotonin levels.

• Sleep Medicine and Psychophysiology
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• v.16 no.2
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• pp.49-55
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• 2009

This review aims to introduce the basic neurobiological aspects of dream. There have been long debates on whether the neurobiology of rapid eye movement (REM) sleep is identical to that of dream. However, many theories on dream are based on the findings of REM sleep. Bizarre cognition and intense emotion in dream have been suggested to derive from physiological (e.g. desynchronized gamma oscillation and postsynaptic inhibition), chemical (e.g. decreased noradrenalin and serotonin, increased acetylcholine and modulation of dopamine), anatomical (e.g. deactivation of dorsolateral prefrontal cortex and activation of limbic and paralimbic areas) change in REM sleep. In addition, dream has been suggested to play its neurobiological roles. Processing of negative emotion may be one of the functions of dream. Dream is also supposed to consolidate memory, especially semantic memory. Despite a number of hypotheses and debates, the neurobiological mechanism of dream generation has not been concluded.