Showing papers on "Slow-wave sleep published in 1968"

Growth hormone secretion during sleep

Abstract: Plasma growth hormone (GH), insulin, cortisol, and glucose were measured during sleep on 38 nights in eight young adults. Blood was drawn from an indwelling catheter at 30-min intervals; EEG and electrooculogram were recorded throughout the night. In seven subjects, a plasma GH peak (13-72 mμg/ml) lasting 1.5-3.5 hr appeared with the onset of deep sleep. Smaller GH peaks (6-14 mμg/ml) occasionally appeared during subsequent deep sleep phases. Peak GH secretion was delayed if the onset of sleep was delayed. Subjects who were awakened for 2-3 hr and allowed to return to sleep exhibited another peak of GH secretion (14-46 mμg/ml). Peak GH secretion was not correlated with changes in plasma glucose, insulin, and cortisol. The effects of 6-CNS-active drugs on sleep-related GH secretion were investigated. Imipramine (50 mg) completely abolished GH peaks in two of four subjects, whereas chlorpromazine (30 mg), phenobarbital (97 mg), diphenylhydantoin (90 mg), chlordiazepoxide (20 mg), and isocarboxazid (30 mg) did not inhibit GH peaks. Altered hypothalamic activity associated with initiation of sleep results in a major peak of growth hormone secretion unrelated to hypoglycemia or changes in cortisol and insulin secretion.

The effect of slow wave sleep and REM sleep on regional cerebral blood flow in cats.

Abstract: Regional cerebral blood flow was measured by means of an autoradiographic technique in unanaesthetized, unrestrained cats during wakefulness, slow wave sleep (S-SW), and rapid eye movement sleep (S-REM). The electrocorticogram, electro-oculogram, and electromyogram from the posterior neck muscles were continuously recorded. All operative procedures were completed at least four days prior to the experiment. Arterial blood samples were obtained immediately prior to the regional cerebral blood flow determination and analysed for PCO2, PO2, pH, and haematocrit. There were no significant differences in these parameters among the three groups. During S-REM there was a significant increase in flow in all twenty-five regions measured which varied from 62 per cent in the cerebellar white matter and sensory-motor cortex to 173 per cent in the cochlear nuclei. During S-SW a significant increase in flow occurred in only ten of the twenty-five regions, and these changes were smaller in magnitude, varying from 26 per cent in the association cortex to 68 per cent in the superior olive. It is postulated that local changes in cerebral metabolism account for the regional cerebral blood flow changes demonstrated.

Spontaneous and evoked unitary activities of cat lateral geniculate neurons in sleep and wakefulness.

Abstract: Unit activities of the lateral geniculate body (LGB) were studied in free behaving cats during arousal, light sleep (sleep with high-voltage, slow EEG) and deep sleep (sleep with low-voltage, fast EEG). The LGB units were classified into two types according to their response patterns to stimulation of the optic chiasm and the visual cortex; by both types of stimulation the P units were fired singly at short latencies and the I units were fired repetitively at long latencies.1. Spontaneous activity of the P units changed markedly upon alternation of the behavioral state. During arousal the P units showed well-spaced regular discharges. During light sleep the grouped discharges consisting of 2-5 spikes became manifest intermingled with sporadic discharges. In deep sleep spontaneous activity was accelarated with occasional bursts of spikes (deep sleep bursts) lasting about 0.5 sec.2. The deep sleep waves of the LGB, which were mass activity of spiky form seen during deep sleep, were found to be correlated to the deep sleep burst of the P unit spontaneous activity in their negative phase. Suppression of the unit activity was seen during their positive phase.3. The rate of spontaneous activity of the P units was lowest during light sleep and increased from arousal to deep sleep.4. The firing probability of the P units to chiasmatic and visual cortical stimulation was lowest during light sleep and increased from arousal to deep sleep. This was true of the firing probability to the spontaneous synaptic bombardment.5. The I units did not alter significantly the rate of spontaneous activity and the strength of responsiveness to visual cortical stimulation when sleep changed from one type to another. Responsiveness of the I units to chiasmatic stimulation was higher during deep sleep than during light sleep, suggesting that orthodromic activation of the I units is mediated via the P units.

Effects of evening activity on early night sleep

Abstract: This study was designed to determine the effects of presleep activity on a variety of physiological variables during 3½ hrs of subsequent sleep. Three presleep conditions were investigated for each of 15 Ss:6 hrs of strenuous physical exercise, 6 hrs of concentrated studying, and 6 hrs of relaxation, i.e. watching TV, listening to records, and reading magazines. The following variables were recorded during a 3½ hr sleep period: EEG, EOG, body movements, heart rate, respiratory rate, peripheral pulse voltime, phasic vasoconstrictions, rectal temperature, and rapid variations in skin potential. None of the experimental presleep activities influenced the EEG cycle during the 3½ hrs of sleep. In particular, there were no significant differences in the following measurements as a result of presleep condition: amount of REMP time, time to first REMP, amount of delta sleep, time to first delta sleep, amount of stage 2 sleep, or number of sleep stage changes. These findings indicate a surprising stability of the sleep stage cycle vis a vis the markedly different evening activities. Physiological arousal after exercise decreased rapidly until it was no longer distinguishable from the base levels following studying or relaxation. A tendency to approach these base levels was observed even in heart rate, a variable which remained elevated after exercise throughout the 3½ hrs of sleep. For none of the physiological variables was the level of physiological arousal during sleep inversely related to the level of physiological arousal during wakefulness. Relating EEG sleep stages to the other variables of this study, it was observed that on nights when respiratory rate was high there was more delta sleep and less stage 2 sleep. Also, respiratory minima were most often found during stage 2 sleep immediately following a REMP, and respiratory maxima during NREM sleep were significantly associated with delta sleep. These results support Bulow's (1963) proposal that a close coupling exists between respiratory centers and those neural structures that regulate EEG arousal.

Effects of a stressful presleep experience on electroencephalographrecorded sleep

Abstract: The effects on experimentally uninterrupted sleep of two films, one psychologically stressful and the other neutral, both seen just before bed, were studied in 12 male Ss on 2 nights according to a balanced design. EEG and electro-ocu-logram recordings were made of the first 6 hours of sleep. The stress film significantly increased the number of awakenings associated with rapid eye-movement periods (REMPs), but not that of non-REM sleep awakenings, as well as the proportion of REMPs terminated by spontaneous awakenings. It furthermore increased the frequency of REMs (REM density) during REMPs. These results suggest that the stress film produced a specific REM sleep disturbing effect via anxiety which carried over into the Ss’ sleep and dreams, and that it increased REM density secondary to drive enhancement.

EEG Sleep Patterns After High Cervical Lesions in Man

Abstract: EVOLUTION of sleep patterns as a primary component of sleep-wakefulness cycles has received much attention in recent years, from both phylogenetic1and ontogenetic viewpoints.2It has become clear that in the premature human infant there is a marked preponderance of "activated" sleep (rhombencephalic, or rapid eye movement [REM] sleep).3,4This phase of sleep in the adult has been strongly associated with dreaming,5and decreased REM sleep in the early postnatal period is associated with appearance of more finely graded sleep patterns which are thereafter separable into light, intermediate, deep, and dream phases.6 The role that such factors as somatic sensory influxes might play in maintenance of normal sleep patterns has not been extensively investigated. At a behavioral level, studied by Berger7in our laboratory have indicated a relationship between conditioned eye movements in the waking state and the amount of eye movements in

Autonomic correlates of eye movement bursts during stage rem sleep

Abstract: During stage REM sleep, eye movements were found to be distributed in discrete bursts of rapid eye movement (REM-bursts). REM-burst time averaged approximately 10 percent of stage REM sleep and the rate within a subject was consistent from epoch-to-epoch and night-to-night. Consistent subject biases in eye movement direction were also found. Within subject correlations were obtained between REM-burst time and autonomic activity. Significant positive correlations were found for respiration rate and number of finger pulse responses. There were positive but insignificant correlations with electrodermal activity, heart rate and decreases in respiration amplitude. Autonomic variability was not significantly associated with REM-burst time.

Electrodermal levels and fluctuations during normal sleep.

Abstract: All night recordings of skin potential (SP) and skin resistance (SR) levels and rapid electrodermal fluctuations (REFs) were taken from a group of college students during two nights of normal sleep. An attempt was made to associate changes in these measures with stages of sleep as identified by EEG patterns. Electrodermal levels could differentiate between wake and sleep but could not clearly identify individual sleep stages or REM periods. REFs were found to increase in number during slow wave sleep and decrease during Stage I REM periods. This diminution of REFs occurred consistently about six minutes before the onset of each REM period and then returned at a lower rate a few minutes after the termination of the REM period.

Sleep and Depression: Further Considerations

Abstract: THE SLEEP pattern of 21 psychiatric inpatients diagnosed as suffering from depression was compared with that of a control group. The differences between the two groups have been described in detail elsewhere. 1 The depressed patients had less actual sleep, stage 4 sleep, and rapid eye movement (REM) sleep; and more awake and drowsy time. They took longer to become drowsy and to fall asleep and awoke significantly earlier in the morning. They had more spontaneous awakenings (especially from stages 1, REM, and 2 sleep). The disturbances were maximal in the last third of the night. The 21 depressed patients constituted a mixed group. The variables included severity and duration of the illness, therapy, age, psychotic-neurotic features, etc. It has been suggested that the nature of the sleep disturbance present in a particular depressed patient may be a consequence of severity, 2 the

REM Deprivation: I. The Effect on Schizophrenic Patients

Abstract: THE FUNCTION of dreaming and its relation to mental illness have recently become more amenable to laboratory investigation because of the discovery of reliable physiological indices of dreaming. Aserinsky, Kleitman, and Dement demonstrated that dreaming regularly occurs during discrete sleep periods characterized by intermittent bursts of conjugate rapid eye movements (REM) and a low voltage desynchronized electroencephalogram pattern (emergent stage 1). 1-3 In the human adult REM sleep alternates with nonrapid eye movement sleep (NREM) in a cycle of approximately 90 minutes, during which REM sleep typically follows NREM sleep. 2 Each night REM sleep occurs about four to six times in successively longer periods lasting 10 to 40 minutes and it occupies about 25% (100 minutes) of total sleep time. 2.4 The unexpected finding that such abundant dreaming occurs at regular intervals every night strengthened the hypothesis that dreaming might be essential

Sleep and Barbiturates: some Experiments and Observations

Abstract: To determine the effect of barbiturates on sleep two subjects, after a control period, received 200 mg. of sodium amylobarbitone for 26 nights. All night sleep records taken during this period showed that the barbiturate shortened the delay to sleep, increased the total sleep period, lengthened the delay to rapid eye movement (R.E.M.) sleep, and depressed R.E.M. sleep. After five nights R.E.M. sleep returned to baseline values —that is, showed tolerance. On stopping the drug withdrawal phenomena were seen, even to this small dose of the drug. In a second experiment a subject dependent on 600 mg. of Tuinal was found to have low normal R.E.M. sleep while on drugs. On withdrawal, delay to sleep increased and total sleep time fell. R.E.M. sleep was doubled and the delay to R.E.M. became abnormally short. These findings suggest that hypnotics allow sleep to be “borrowed,” and that patients should be supported while they are being withdrawn.

Secobarbital and nocturnal physiological patterns.

Abstract: Sleep patterns of 14 male Ss were examined following a single oral dose (200 mg) of the barbiturate secobarbital. Compared to baseline, medication caused definite changes in the amount and distribution of the EEG stages of sleep. With the drug, a decrease in percent stage REM and an increase in percent stage 2 were accompanied by fewer body movements and a trend toward less waking. A more striking effect was the drug-induced redistribution of EEG stages with slow-wave sleep potentiated during the first half of the night but virtually eliminated during the last half. Stage REM, on the other hand, was inhibited in the first half but returned to baseline levels in the last half of the night. Recent evidence suggests that such effects could result from modulation of brain levels of the monoamines. Within the stages of sleep the amount of fast EEG activity was increased by the drug, with a tendency toward desynchrony. Pre-central beta activity became especially prominent in stages REM and 2 (low-voltage phases), and this change was associated with inhibition of such phasic events as eye movements during REM sleep, sigma spindles during stage 2 and spontaneous electrodermal responses in slow-wave sleep. Thus, it appears that secobarbital potentiates tonic and suppresses phasic phenomena during sleep. A possible interpretation of these results is that secobarbital enhances electrical activity in forebrain structures (Routtenberg's arousal system II) while inhibiting the reticular activating system (arousal system I) causing a reduction of phasic variability in all stages of sleep.

The displacement of stages 4 and rem sleep within a full night of sleep

Abstract: Stage 4 typically occurs dominantly in the first third of a normal night of sleep and REM sleep occurs dominantly in the last third of the night. In this experiment conditions were imposed to prevent these stages from occurring at their usual peak periods. Stage 4 sleep was permitted to occur only during the last two hours of sleep and REM was permitted to occur only during the first two hours of sleep. The results show that each stage can be partially displaced to the peak period of the other, but that stage 4 sleep is elicited more readily late in the sleep period than is REM early during the night.

REM organization in neonates. Theoretical implications for development and the biological function of REM.

Abstract: IN THE course of a study of individual differences among the newborn, 1,2 behavioral observations of rapid eye movement (REM) sleep and related spontaneous discharges were made on 2 to 3-day-old normal neonates. The observations were geared to issues which have been raised in the REM literature. The object of the observations was to replicate, and, if possible, to extend what is known about REM sleep in neonates and to test whether certain characteristics of adult REM sleep also hold for infants. The following issues guided the data collection. 1. Roffwarg et al 3 found that the sequence between wakefulness and sleep in the neonate is the reverse of that in adults. In the normal adult, nonrapid eye movement (NREM) sleep always precedes REM sleep by 50-90 minutes, whereas infants enter REM sleep in almost direct transition from the waking state.