REM Sleep Duration Research Articles

Nocturnal penile tumescence in healthy aging men.

This study investigated nocturnal penile tumescence (NPT) and verified degree of sleep erections by direct observation in 40 healthy, sexually nondysfunctional men aged 23-73. They were assessed under similar conditions during three nights, with systematic awakenings during tumescent episodes on the third night. Total sleep time and the ratio of total sleep time to time in bed (sleep efficiency) decreased significantly with age. Duration of REM sleep after adjustment for differences in sleep time did not vary significantly after age 30. Frequency and duration of NPT, but not degree of circumferential increases during tumescent episodes, decreased progressively with age independent of variations in sleep. In contrast to men in the younger age groups, the majority of men above age 60 did not have full sleep erections even though they and their partners reported regular intercourse. The significance of this finding is discussed in relation to the neurophysiology of erection and to NPT as a diagnostic test of impotence in aging men.

The timing and duration of sleep in partial sleep deprivation therapy of depression.

The antidepressant response to partial sleep deprivation early in the night (PSD-E) was compared with the response to partial sleep deprivation late in the night (PSD-L) in 16 drug-free depressed inpatients using a balanced order crossover design. PSD-L had a significantly greater antidepressant effect that PSD-E. The response to PSD-L was sustained and enhanced by a second night of treatment. Patients had significantly shorter sleep durations and reduced REM sleep on PSD-L that did not occur in the PSD-E situation. There was a significant negative correlation between response to PSD and sleep duration, and in particular, REM sleep duration, in the late sleep deprivation situation. Thus, the amount and timing of sleep appear to be factors in the response to PSD, but additional studies are needed to evaluate the relative importance of these parameters.

Disturbances of sleep and wakefulness associated with the use of antihypertensive agents

Sleep disturbances are frequently associated with the use of antihypertensive drugs. They are observed mainly during the administration of drugs that affect central adrenergic mechanisms. β-adrenoceptor antagon its which readily penetrate into the brain (propranol o l, pindolol) increase wakefulness and/or decrease REM sleep. α 2-adrenoceptor agonists (clonidine, guanfacine) markedly reduce the duration of REM sleep. The catecholamine depleting agent reserpine increases REM sleep during single or repeated-dose administration, while the MAOI phenelzine shows opposite effects. The 5-HT2 antagonist ritanserin, which is chemically related to the antihypertensive agent ketanserin, increases slow wave sleep while REM sleep is decreased. Sleep disturbances have not been reported during the administration of calcium entry antagonists. However, they seem to modify the effects of hypnotics and CNS stimulants. There are no formal studies on the effects of angiotensin converting enzyme inhibitors and vasodilators on sleep in man.

Hypercapnia alters sleep state pattern.

Mild hypercapnia in the adult animal does not affect sleep pattern but more severe hypercapnia in the fetus increases the duration of REM sleep. Adult male rats were exposed daily for 2-3 h sessions at random to 6, 7, and 8% CO2 or room air. Breathing CO2 caused a 60% increase in sleep onset latency, a 28% decrease in sleep duration, but no change in percent time spent in REM. However, the duration of REM sleep episodes increased by 30%. Thus, in both fetal and adult animals severe hypercapnia appears to have a similar effect on sleep pattern.

REM sleep signs rostral to chronic transections at the pontomedullary junction

The brainstems of 3 cats were transected at the ponto-medullary junction and the cats maintained in stable condition for periods of from 16 to 31 days. After transection, all of these cats had periods in which forebrain sensorimotor cortex, olfactory bulb, hippocampus, eye movement and lateral geniculate recordings exhibited the pattern of activity seen only in REM sleep in the intact cat. We conclude that medullary regions are not required to generate these signs of REM sleep. The pons is necessary for REM sleep and is sufficient to produce REM sleep signs in rostral as well as caudal brain regions. However, the medulla may contribute to regulation of the duration and periodicity of REM sleep.

REM sleep deprivation decreases the antinociceptive property of enkephalinase-inhibition, morphine and cold-water-swim

1. 1. Rats treated with phosphoramidon (an enkephalinase-inhibitor 250 μg, i.c.v.), morphine (20 μg i.c.v.) or subjected to cold-water-swim (CWS, animals forced to swim in water at 5°C for 5 min) showed consistent analgesia. 2. 2. The antinociceptive effect of phosphoramidon, morphine and CWS was antagonised by REM sleep deprivation (REMSD). 3. 3. It is suggested that normal duration of REM sleep is of importance for the anti-nociceptive activity of endogenous and exogenous opiates.

Enregistrement de la ventilation au cours du sommeil par pneumotachographie: inconvenients et avantages

Pneumotachographic recording of ventilation requires an air-tight nasobuccal face-mask which might disturb the subjects' sleep and thereby modify their breathing pattern. In a cross-over randomised study we compared recordings obtained with and without a face-mask in 20 healthy normal volunteers (10 males, 10 females, mean age = 21.7 +/- S.E.M. = 0.5). The sleep modifications that resulted from the presence of the face-mask were a lengthening of the REM-sleep latency (+ 38%; P less than 0.01), an increase in intra-sleep waking-time (+ 65%, P less than 0.05), an increase in stage I duration (+ 40%, P less than 0.02), and a decrease in REM-sleep duration (- 20%, P less than 0.01), resulting in a decrease in total sleep duration (- 9%, P less than 0.05). The sleep latency, the number of awakenings, the stage II duration, the deep slow-wave sleep duration, the sleep stability, and the number of sleep cycles were not significantly modified.

Rem Sleep and Ambient Temperature in Man

Five young adult males slept two consecutive nights under each of the five ambient temperatures chosen within the usual range: 13 degrees C, 16 degrees C, 19 degrees C, 22 degrees C, and 25 degrees C. Bedding and other ambient parameters were kept constant under all five ambient temperature conditions. The average REM cycle length significantly decreased when the ambient temperature increased from 13 degrees C to 25 degrees C. Other REM sleep characteristics such as total duration of REM sleep, average REM period, and REM sleep latency did not significantly differ from one ambient temperature condition to another.

Facilitation de l'etat de veille d'un traitement semi-chronique par la Sulbutiamine (Arcalion) chez Macaca mulatta

Cortical electroencephalographic (EEG) activities and nycthemeral states of vigilance organization were studied in 6 adult rhesus monkeys during subchronic administration (10 days) of Sulbutiamin, a synthesized derivative of thiamine (300 mg/kg/day). Sulbutiamin induced the following modifications: (1) In the EEG activities: increase in occurrence of fast rhythms (over 28 c/sec) during waking and also during slow sleep (SS) in which their amplitude doubled. SS spindles increased in number and amplitude. (2) In vigilance organization: waking was enhanced all along the 24 h recording and SS was reorganized (particularly at night), mostly light sleep: large decrease in stage 2 duration, increase in stage 1. REM sleep duration remained stable. These changes, occurring at around day 5 of the treatment, were more pronounced on day 10 and disappeared 2-5 days after withdrawal. This study demonstrated the clear action of Sulbutiamin upon the mechanisms regulating waking and light sleep.

Sleep in piglets: An observational study

The development of sleep was examined in 16 piglets during their first 5 weeks of life. Each piglet was observed for one 90 min period each week and a record of the duration of lying, non-REM-sleep and REM-sleep was made. Sleeping position was also recorded. The amount of time spent sleeping and lying did not change systematically over the 5 weeks and neither did the duration of a sleeping episode. However, the duration of REM-sleep decreased from Week 1 to Week 5. REM-sleep could readily be divided into bouts and whereas the median bout length, number of bursts of REM-sleep per bout and duration of each burst remained constant, the mean number of bouts per observation period showed a marked decline with age. REM-sleep was seen to occur more frequently in the crouch position (all 4 legs folded under the body) than in any other position. It was concluded that the development of sleep follows a similar pattern to other precocious and non-precocious species and that piglets are probably not sleep-deprived.

Sleep induced by low doses of apomorphine in rats

The effect of apomorphine on the EEG of freely moving rats was studied. Apomorphine at the dose of 1 mg/kg caused stereotypy and a marked reduction of total sleep. On the contrary, acute subcutaneous administration of apomorphine at the dose of 100 μg/kg, or less, markedly increased the amount of total sleep (corresponding mostly to synchronized sleep). Moreover, the infusion of apomorphine (80 μg/kg/h) for 4 h doubled the duration of slow and REM sleep. The hypnotic effect of apomorphine was prevented by neuroleptics, such as pimozide, benzperidol and l-sulpiride, at doses which, per se, did not modify the EEG of the animals. These results suggest the existence in the CNS of DA receptors mediating sleep.

Pimozide attentuates d-amphetamine-induced sleep changes in man

Pretreatment with pimozide (mean dose = 13 mg/day) blocked the effect of d-amphetamine (20 mg base, administered by intravenous bolus infusion at 0815) on all-night EEG sleep patterns in seven hospitalized psychiatric patients. Each patient was studied for five nights (2 nights baseline, 1 night on the day of the infusion, and 2 nights recovery) with and without pretreatment with pimozide. Without treatment with pimozide, d-amphetamine significantly reduced duration of total sleep, REM and nonREM sleep, Stage I, and Stage II. With coadministration of pimozide, d-amphetamine had no effect on sleep. These results suggest that the d-amphetamine induced changes in sleep are mediated by dopaminergic neurons.

Sommeil de l'enfant presentant des manifestations episodiques du sommeil: Comparaison avec l'enfant normal

1. (1) The sleep pattern of 23 children, aged 5–12 years, with episodic nocturnal phenomena (night-terrors, somnambulism, rhythmic movements) was recorded during two successive nights. It was compared with that of a group of 21 normal children of the same age. 2. (2) In the pathological group, slow wave sleep (SLP, stages 3 and 4) was significantly shortened during the 2 nights. This deficit mainly involved the first 3h of sleep. 3. (3) As for the slow wave sleep, REM sleep (SP) modifications prevailed during the first hours of sleep. The first REM period was delayed and preceded by more numerous and atypical partial REM periods. The duration of the first REM period increased faster as a function of its latency than in the normal child. 4. (4) In contrast with this difficulty for REM sleep to occur during the first part of the night, the subsequent REM sleep pattern was similar in the 2 groups (total REM sleep duration, mean REM period duration, mean REM cycle duration). For equal latencies, REM periods had similar duration. Finally, the total REM sleep amount was a linear function of the total sleep time, with more or less identical coefficients for the two groups. 5. (5) The part played by these modifications during the first hours of sleep in the occurrence of night terrors and somnambulism is discussed.

Induction and Resetting of REM Sleep Rhythm in Normal Man by Arecholine: Blockade by Scopolamine

Arecholine, a cholinergic muscarinic agonist, was administered intravenously 35 min after sleep onset in eight normal volunteers who had been pretreated with either methscopolamine or scopolamine, muscarinic receptor blockers that do not and do cross the blood--brain barrier, respectively. Following pretreatment with methscopolamine, arecholine shortened the REM latency and increased the number of REM periods without altering the duration of individual REM periods or altering the REM--REM intervals. Pretreatment with scopolamine blocked the effects of arecholine. The results support the hypothesis that cholinergic muscarinic mechanisms are involved in the timing but not the duration of REM sleep.

Prostaglandins and sleep. Awaking effect of prostaglandins and sleep pattern of essential fatty acids deficient (EFAD) rats

The experiments were carried out to investigate the effects of prostaglandins (PGs) on the sleep pattern in the cat, and in normal and EFAD rats. The data indicate that the duration of slow wave sleep (SWS) was significantly longer in EFAD rats compared with the normal rats. However, no difference in the REM sleep was observed between the two groups. Intraventricular (i.vc.) administration of PGE 1, PGE 2 and PGF 2α increased wakefulness without a significant alteration of REM sleep. PGE 1 administered i.vc. did not alter the duration of SWS or REM sleep in the chronic cat, but induced ponto-geniculo-occipital (PGO) waves (spikes) which are the phasic phenomenon of REM sleep. The fact that previous administration of 5-hydroxytryptophane abolished the PGE 1-induced PGO spiking, might indicate that this drug triggered the spikes mainly via the functional inhibition of the serotonergic system.

Physostigmine alters onset but not duration of REM sleep in man

Physostigmine (1.0mg) or placebo were administered intravenously over 1-h period to seven male normal volunteers beginning 35 min after sleep onset. The results indicate that physostigmine induced the onset of REM sleep but did not significantly alter the duration of individual REM sleep periods. Physostigmine significantly shortened the REM latency and the duration of the second nonREM period. After inducing the onset of the first REM period(s); physostigmine also appeared to advance succeeding REM-nonREM sleep cycles relative to sleep onset even when the duration of each cycle was unaffected.

Organisation temporelle de l’activité électrique du cortex cérébral et de la paroi musculaire digestive à la naissance

The awake-like state in the foetal lamb (less than 10 p. 100 of the recording time ) was increased to 50 p. 100 at the expense of REM-sleep within 3 days in the neonate, the N REM-sleep duration being unchanged. The irregular spiking activity (ISA) of the foetal small intestine was also increased at the expense of quiescence in the fed-milk lamb, without changes in the regular spiking activity (RSA) duration. It is concluded that reactions to both the environment and the digestive bulk are only transient disruptive factors of an intrinsic cyclic sequence of events.

Behavioural and motor excitation and inhibition induced by the administration of small and large doses of somatostatin into the amygdala

The administration of lower (0.01, 0.1 μg) and higher (1.0, 10.0 μg) doses of somatostatin (SRIF) into the amygdaloid complex revealed a dose-dependent dissociation of effects on behaviour and motor control. While the lower doses generally induced a behavioural excitation accompanied by a variety of tremors and stereotyped movements, the higher doses prevented the expression of a normal behavioural pattern due to the severity of disturbances in motor control. The sleep-waking cycle was also affected; the duration of REM sleep showed a consistent dose-related reduction although the total sleeping time was not considerably altered. This was due to a paradoxical dose-related prolongation of shallow slow wave sleep (drowsiness) which typically accompanied the periods of immobilization caused by motor control difficulties. Electrophysiologically, this phenomenon was often reflected in a paradoxical pattern characterized by a dissociation of EEG from behaviour. The specificity of SRIF effects was tested by administration of some endocrinologically active and inactive analogues of SRIF via the same route. None of the analogues tested induced effects comparable to those observed after the administration of the same dose of the native hormone.

Effect of clonidine on sleep patterns in man.

Clonidine (300 microgram orally) increased in man the total duration of sleep and strikingly reduced the duration of REM sleep. Yohimbine (10 mg per os) did not alter the sleep patterns in man but antagonized the effects of clonidine. These results provide evidence that an alpha sympathomimetic mechanism could suppress REM sleep and increased the total duration of sleep.

Sleep-inducing effect of a high-protein diet in sheep

The possibility that dietary nitrogen enchances sleep duration was investigated. An increase microbial protein production was obtained by addition into the rumen of 0.1–0.4 g/kg of coating urea in 2 sheep with continuous monitoring during 2 months of polygraphic activity and ingestive behavior. The data demonstrate an increase in both NREM and REM sleep duration on a high-protein diet irrespective of the physical nature of the regimen.