Showing papers on "Slow-wave sleep published in 1978"

The relationship between changes in REM sleep and clinical improvement in depressed patients treated with amitriptyline

Abstract: EEG sleep recordings were obtained on consecutive nights from six hospitalized depressed patients before, during, and after treatment with amitriptyline for a total of 370 nights of data, about 85% of all nights of the study. Amitriptyline significantly reduced time spent in rapid eye movement (REM) sleep and prolonged the REM latency throughout the treatment period. Three patients who improved during treatment showed a REM rebound when amitriptyline was discontinued, whereas three patients who did not improve showed no REM rebound.

Effects of high ambient temperature on sleep in young men.

Abstract: Each of 10 normal subjects had 4 nights of laboratory-monitored sleep, consisting of adjustment, baseline, high blanket temperature (HBT), and recovery nights. EEG-EOG recordings were made on each night; rectal temperature, heart rate, body weight, and ambient temperatures were monitored throughout the last 2 nights. On the HBT night, subjects had less total sleep time, more frequent and longer awakenings, greater shifting among sleep stages, decreased amounts of stage 1 REM and stages 3 + 4, and delayed onset of deep sleep (stages 3 and 4). Body temperature was elevated to a relatively constant level of 37 degrees C on the HBT night, but gradually decreased from 36 degrees C to 34.5 degrees C across the recovery night. Heart rate decreased at a linear rate on both the HBT and recovery nights, but was 15 beats/min faster on the former. Subjects experienced liquid loss of 1.25 kg on the HBT night, but had a full recovery by the following evening.

Physical fitness, exercise, and human sleep.

Abstract: Restorative theories of SWS predict a positive relationship between SWS and daytime exercise. However the relevant data appear contradictory. It was hypothesized that the discrepancy in the literature was due to the varying physical fitness levels of subjects used in these studies. The hypothesis was tested, using human subjects, by varying amount of exercise and level of fitness in a 2x2 design. Two effects were observed, both supporting the hypothesis. First, fit subjects had higher levels of SWS than unfit subjects. Second, following exercise, the level of SWS increased in fit, but remained unchanged in unfit subjects.

Daily pattern of sleep, motor activity and feeding in the rat: Effects of regular and gradually extended photoperiods

Abstract: 1. The vigilance states (waking, slow wave sleep (SWS) and paradoxical sleep (PS)), motor activity, food intake and water consumption were continuously recorded by telemetry in unrestrained rats. The animals were maintained for 2 days under 12-h light−12-h dark conditions (LD 12∶12). Subsequently, the photoperiod was gradually extended by 1 h/day from 12 to 20 h, and restored to the original length for the last 2 days. In one group of animals the extension of the photoperiod was obtained by phase-advancing light-onset (La-group), in the other by phase-delaying dark-onset (Dd-group). 2. During the LD 12∶12 control period, sleep, motor activity and food intake exhibited an asymmetric daily distribution. The percentages (Fig. 2) and episode durations (Fig. 4) of total sleep (TS) and slow wave sleep (SWS) were highest at the beginning of the light-phase and then exhibited a decreasing trend. The corresponding values for PS showed a slight increasing trend during the light-phase. A marked increasing trend during the light-phase was seen for PS expressed as the percentage of TS. Motor activity (Fig. 3) was minimal and food intake (Fig. 6) absent during the first half of the light-phase, increasing gradually during the second half. The daily minimum of sleep and the daily maximum of motor activity were situated at the end of the dark-phase. 3. During the extension of the photoperiod the daily period of high activity and waking was shortened and remained largely restricted to the dark-phase (Figs. 7–9). Motor activity and food intake were more restricted to the dark-phase in the La-group than in the Dd-group. Throughout the experiment, the percentage of PS relative to TS remained lower at the beginning of the light-phase than towards its end, whereas the values for TS and SWS tended to show an inverse relationship (Figs. 9–11). After restoration of the original LD 12∶12 condition, the altered daily patterns of sleep and motor activity tended to persist. 4. The daily pattern of sleep in the rat with the predominance of SWS in the early part of the rest period, and of PS in the late part, is strikingly similar to the distribution of sleep states in man. The difference in the daily rhythms of SWS and PS may reflect a phase-difference of two separate, and partly independent, circadian oscillators.

Overnight Plasma Profiles of Melatonin and Certain Adenohypophyseal Hormones in Men

Abstract: Melatonin levels exhibited a day-night rhythm with highest levels at night. Nocturnal plasma melatonin concentrations were unrelated to sleep stages, whereas secretion of GH was temporally related to slow wave sleep. Levels of corticotropin rose in the later sleep cycles. We found no relationship between endogenous nocturnal melatonin and adenohypophyseal hormone levels. The results indicate that in young men nocturnal levels of melatonin are controlled separately from those of LH, PRL, corticotropin, and GH.

Nocturnal sleep in separated monkey infants.

Abstract: • Nocturnal sleep was recorded from ten unrestrained, groupliving Macaca nemestrina (pigtail) monkey infants, using implantable multichannel biotelemetry systems, during the agitation-depression behavioral reaction that follows maternal separation. Sleep disturbances during the four nights of separation were characterized by decreases in rapid eye movement (REM) time and in the number of REM periods, and increases in REM latency. Time awake and number of arousals were increased. Slow-wave sleep was not significantly affected. Sleep pattern changes were most pronounced the first separation night, and tended to decrease as separation continued, whereas behavioral measures of depression tended to increase as separation continued (up to four days). Sleep patterns returned to normal following reunion with the mother. Those infants who had the most severe sleep disturbances the first separation night (more time awake, less total sleep, less REM) also tended to become most depressed behaviorally later in the separation period.

Effectiveness of Temazepam with Short-, Intermediate-, and Long-Term Use: Sleep Laboratory Evaluation

Abstract: The effectiveness of 30 mg temazepam (SaH 47-603) for inducing and maintaining sleep was evaluated in the sleep laboratory in six insomniac subjects under conditions of short-, intermediate-, and long-term drug administration Administration of temazepam had no effect on sleep induction In addition, effectiveness was not demonstrated for sleep maintenance: wake time after sleep onset was not significantly decreased on any of the three drug conditions, while the number of nightly awakenings was significantly decreased on all three drug conditions Total wake time was decreased only slightly with short-term drug administration and was similar to baseline with intermediate- and long-term use The percent REM sleep was essentially unchanged throughout the drug administration period On the initial set of withdrawal nights, the per cent REM sleep was slightly but no significantly increased over baseline The per cent slow wave sleep decreased significantly with short-, intermediate-, and long-term drug administration After withdrawal, the percent slow wave sleep returned to baseline values

Physostigmine alters onset but not duration of REM sleep in man.

Abstract: Physostigmine (1.0 mg) 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 non REM 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.

Home-Recorded Sleep in 2− and 9-Month-Old Infants

Abstract: Home recorded videotapes of all-night sleep were obtained for 32 2-month-old and 38 9-month-old infants. Changes in the proportionate amounts of time spent in active sleep, quiet sleep, wakefulness, and out of the crib were significantly related to age. Sleep-cycle lengths did not change with age, but the state relationships within sleep cycles showed maturational effects. Temporal patterning of sleep states was present by 9 months. Time-lapse video recording of sleep provides an opportunity for nonobtrusive monitoring of sleep longitudinally in normal and pathological infants.

Chronic Primary Insomnia: Possible Physiopathological Involvement of Slow Wave Sleep Deficiency

Abstract: This study was designed to compare the sleep of a carefully selected group of patients with chronic primary insomnia toage- and sex-matched controls, in order to investigate the possible physiopathological role of slow wave sleep deficiency in this disturbance. In addition, the effect of age on normal sleep was studied in a group of 40 normal subjects. Sleep was recorded in the laboratory and automatically scored with an electronic system already described. The general trends of sleep stages were computed. Aging in normal subjects was characterized by a sharp decrease of stage 4, but a good stability of stage 3. Insomniacs' sleep showed a sleep-waking imbalance and a marked deficiency in stages 3 and 4. This deficiency seems to be similar to the age effect in normals, but more accentuated; it cannot be attributed merely to increased pressure of wakefulness. We suggest that slow wave sleep is involved in sleep induction and maintenance, and that its deficiency is linked to the fragility of sleep in chronic primary insomnia.

The effect of physostigmine on normal human sleep and dreaming.

Abstract: • Physostigmine, an anticholinesterase that increases the action of brain acetylcholine, induces rapid eye movement (REM) sleep in normal humans. In this study we show that man dreams during physostigmine-induced REM sleep. Seventeen normal volunteers were pretreated with methscopolamine and received one intravenous infusion per night of either placebo or physostigmine either ten or 35 minutes after sleep onset. Subjects were awakened at specific times after infusion and interviewed regarding any sleep mentation prior to awakening. Results indicated that dreaming occurred during physostigmine-induced REM periods but that physostigmine did not alter mentation during non-REM sleep. These dreams were similar to spontaneous REM sleep dreams in content, vividness, unusualness, and emotionality.

A psychophysiological investigation of the long-term effects of clozapine upon sleep patterns of normal young adults.

Abstract: A 25-night single-blind cross over design was employed to determine the long-term effects of clozapine on the sleep patterns of six normal young adults. Subjects received 12.50 mg placebo on the first and last five nights, whereas on the intermediate 15 nights 12.5 mg clozapine was administered. The subjects slept in the laboratory on the third and fourth nights to obtain baseline recordings, and on the eight, twelfth, sixteenth, and twentieth nights to determine the effects of clozapine on sleep variables. Recordings on nights 21 and 25 were used to assess withdrawal effects. Percentage stage 1 sleep and indices of body movements during sleep were significantly reduced, suggesting that clozapine may have sleep-inducing properties. There was no significant rebound of stage REM sleep during drug withdrawal despite a small but significant reduction in stage REM during drug administration. Numerous side effects, indicative of sleepiness, were reported on the mornings following drug administration, and there was evidence of a rapid tolerance to clozapine. These findings may limit the efficacy of clozapine as an hypnotic agent over an extended period of time. Further research on insomniac subjects is therefore indicated.

Effect of intermittent truck noise on percentage of deep sleep

Abstract: Sleep was divided into only two categories, ’’deep’’ and ’’shallow,’’ the latter including waking, stage 1, and dreaming. For the sake of objectivity and precision the criterion was the level of alpha frequency and/or the audibility of spindles (from a speeded up tape recording of the EEG signals from frontal electrodes), which were timed by stopwatch. Twenty truck noises, presented every other night at peak levels of 65 dB (A‐weighted), reduced deep sleep of 12, mainly young subjects by an average of 3%. Adaptation of the waking response occurs despite the separation of the noise nights by at least one quiet night. Adaptation to sleeping in the laboratory appears to continue for more than the one or two nights usually assumed.

The REM cycle in altered sleep/wake schedules.

Abstract: The length and rhythmicity of the REM cycle was studied using data from three laboratories. In the three studies, 25 subjects obtained their sleep in naps under three different sleep/wake schedules: 60/160 min (N =8), 30/60 min (N =10), and 60/120 min (N =7), over a period of 40 hrs to 10 days. Previous results from these subjects (Moses, Lubin, Johnson, & Naitoh, 1977) indicated that the REM cycle is sleep-dependent, rather than an expression of an ongoing Basic Rest-Activity Cycle (BRAC). As a further test of the sleep-dependent hypothesis, autocorrelation and r2 analysis was applied to the compressed sleep (i.e., all wake time between and within sleep periods subtracted) of the baseline, nap, and recovery conditions. Compared to baseline, there were no significant differences in nap REM cycle length in the 60/160 and 60/120 groups; the 30/60 group had significantly shorter cycles. It appeared that this REM cycle shortening was due to the significantly shorter REM episodes in this group. The nap r2 values were significantly lower than baseline in the 30/60 and 60/120 groups, indicating increased variability in the timing of REM episodes during naps. All the nap r2 values, however, were significantly larger than those obtained from a random distribution of sleep stages. To further examine the effects of the degree of sleep fragmentation on REM cycle rhythmicity, two additional groups of subjects whose sleep was fragmented by either REM or SWS deprivation were compared to the nap groups. REM deprivation was the most disruptive of REM cycle rhythmicity; the r2 values for REM deprivation were significantly less than those for napping or SWS deprivation. These data offer further support that the REM cycle is a sleep-dependent rhythm and is not an expression of an ongoing BRAC.

Electroencephalographic sleep recordings and depression in the elderly.

Abstract: Eighteen patients over the age of 60 who were experiencing a major depressive episode were studied on a Clinical Research Unit after they had been drug-free for at least two weeks. All-night electroencephalographic (EEG) recordings revealed considerable fragmentation of sleep, a mean sleep efficiency of 58 percent, and very little delta sleep. The findings of reduced sleep time, shortened REM latency, and high REM density were similar to those in depressed patients under the age of 60. These preliminary findings support the application of EEG sleep recordings as a tool for the differential diagnosis of depression in the elderly.