Showing papers on "Non-rapid eye movement sleep published in 1979"

Phase advance of the circadian sleep-wake cycle as an antidepressant

Abstract: Sleep in depressed patients resembles sleep in normal subjects whose circadian rhythms of temperature and rapid-eye-movement sleep are phase-advanced (shifted earlier) relative to their sleep schedules. If this analogy is relevant to the pathophysiology of depressive illness, advancing the time of sleep and awakening should temporarily compensate for the abnormal timing of depressed patients' circadian rhythms. Four of seven manic-depressive patients studied longitudinally spontaneously advanced their times of awakening (activity onset) as they emerged from the depressive phase of their illness. In a phase-shift experiment, a depressed manic-depressive woman was twice brought out of depression for 2 weeks by advancing her sleep period so that she went to sleep and arose 6 hours earlier than usual. The antidepressant effect of the procedure was temporary and similar in duration to circadian desynchronization induced by jet lag in healthy subjects. This result supports the hypothesis that abnormalities of sleep patterns in some types of depression are due to abnormal internal phase relationships of circadian rhythms.

Systematic Trends Across the Night in Human Sleep Cycles

Abstract: The durations of successive sleep cycles, defined according to NREM (stage 2) or REM onsets, were objected to trend analysis in three groups of normal subjects and in a group of elderly patients with chronic brain syndrome (CBS). NREM sleep cycles showed consistent curvilinear trends for all groups except that the trend in children was distinguished by a lengthy first NREM cycle. REM steep cycles showed quite similar curvilinear trends for the three normal age groups with the middle two cycles being longer than the first and fourth. In the CBS patients, REM sleep cycles did not show a significant trend across the night. Real-time cycles (i.e., with time awake included) manifested trends quite similar to those excluding waking. The trends in sleep cycle durations are normative characteristics of sleep which may not be apparent on a single night. A more constant cycle was found in the CBS elderly and may indicate brain pathology. Sleep cycle trends, along with such other temporal characteristics as the decline in stage 4, may provide clues to the metabolic processes which underlie the sleep EEG. They also provide a more exact basis for investigation of hypothesized biorhythm correlates of NREM-REM cycles.

Successful separation of depressed, normal, and insomniac subjects by EEG sleep data.

Abstract: • Data from all-night EEG sleep studies were used to distinguish normal subjects, primary depressed patients, and primary insomniac patients. In part 1, we compared 41 normal subjects, 56 depressed patients, and 18 insomniacs. In a univariate comparison with normal subjects, depressed patients showed less total sleep, longer sleep latency, more early morning awake time, more intermittent awake time, less delta sleep, less sleep efficiency, and shorter rapid eye movement (REM) latencies; compared with insomniacs, depressed patients showed greater early morning awake time, shorter REM latency, greater REM index, and greater REM density. Using multivariate discriminant analysis, 82% of the sample were correctly classified by diagnosis: 100% of the normal subjects, 72% of the depressed patients, and 77% of the insomniacs. Eight variables contributed to the multivariate separation of depressed individuals from insomniacs and normals: total sleep time, total recording period, sleep efficiency, sleep latency, early morning awake time, awake time, REM time, and REM %. When the discriminant functions were applied to a second group of 18 primary depressed patients, 82% were correctly classified as depressed. These results suggest that primary depressed patients and primary insomniac patients may show relatively characteristic patterns of sleep abnormality.

Effects of total sleep loss on sleep tendency.

Abstract: Effects of two nights of sleep loss were assessed in six young adult (18--21 yr.) volunteers (2 women, 4 men). Performance on the Wilkinson Addition Test fell significantly below baseline values during the sleep-loss procedure and recovered after one or two full nights of sleep. Performance on a Serial Alternation Task also declined during sleep loss. Mood and sleepiness, assessed by subjective self-rating scales, showed a significantly less positive mood and a greater degree of sleepiness during sleep loss, with a recovery to baseline levels after one full night of sleep. Sleep tendency, measured at 2-hr. intervals during all waking periods, was assessed using an objective measure of latency to sleep onset, the Sleep Latency Test. The scores fell to about 1 min. at 0600 on the first night of sleep loss and remained at similarly low values throughout the sleep loss period. After one night of recovery sleep the scores remained significantly below baseline levels, which were not achieved until after the second recovery night. The multiple sleep latency test appears to be a valuable operationally defined tool for measuring daytime sleepiness.

Sleep-deprivation: Effects on sleep and EEG in the rat

Abstract: 1. The vigilance states (waking, rapid eye movement (REM) sleep, and non-REM (NREM) sleep), motor activity, food intake and water intake were continuously recorded by telemetry in unrestrained rats. In addition, an amplitude measure and a frequency measure (number of zero-crossings (ZCR) per 10 s) of the telemetered EEG-signal was obtained. The animals were recorded during a control day, then subjected to 12-h or 24-h sleep-deprivation (SD) by means of a slowly rotating cylinder, and subsequently recorded for further 1–2 days. The EEG-parameters were recorded also during SD. 2. On the control day, the EEG-amplitude of NREM-sleep exhibited a decreasing trend in the 12-h light-phase (Figs. 3, 4). The occurence of slow wave sleep (SWS; defined as the NREM-sleep fraction with less than 40 ZCR/10 s) was practically limited to the first part of the light-phase (Figs. 2, 4). Cumulative plots of the zero-crossing bands (Fig. 2) revealed a prominent daily rhythm in the EEG-frequency distributionwithin NREM-sleep. 3. The percentage of NREM-sleep and REM-sleep was little affected by the 12-h SD, but the amount of SWS and the EEG-amplitude of NREM-sleep were increased (Figs. 4, 6). After a 24-h SD period terminating before light-onset, NREM-sleep was reduced and REM-sleep was markedly enhanced (Figs. 4, 6; Table 1). Both the duration and frequency of REM-sleep episodes were increased, and episodes of total sleep prolonged (Table 2). The amount of SWS was significantly more increased after 24-h SD than after 12-h SD, whereas the EEG-amplitude of NREM-sleep was enhanced to a similar extent after both SD-schedules (Tables 1, 3 Fig. 6). 4. After a 24-h SD period terminating before dark-onset, sleep (particularly REM-sleep) was enhanced in the first hours of the dark-phase, yet the usual high activity bouts prevailed in the later part of the dark-phase (Figs. 7, 8; Table 1). The extent and time-course of REM-sleep rebound was similar after the two 24-SD schedules, whereas SWS-rebound was different: SWS exhibited a one-stage rebound when recovery started in the light-phase, and a two-stage rebound when recovery started in the dark-phase (Fig. 9). 5. A comparison of the effects of 12-h SD performed with the usual and with the double cylinder rotation rate, showed only small differences, indicating that forced locomotion was a minor factor in comparison to sleep-deprivation (Fig. 10; Table 1). 6. The daily pattern of SWS on control days, and the marked increase of SWS after SD correspond to the results from other animal and human studies. It is proposed that due to the existence of an intensity dimension, NREM-sleep is finely regulated around its baseline level, and thus may be readily and accurately adjusted to current ‘needs’, whereas REM-sleep, lacking an apparent intensity gradient, is regulated around a level which is considerably below baseline. Thus, in contrast to NREM-sleep, REM-sleep compensation can occur only by an increase in the time devoted to this state, thereby curtailing the time available for other activities.

Sleep in young and old rats.

Abstract: Five young rats, age 152--175 days, and six old rats, age 782--801 days, all of the F-344 strain, were compared by electronic methods for amplitude of slow wave activity during sleep and for other sleep parameters. Unlike humans, who show a pronounced loss of slow wave activity with advanced age, no significant difference in delta activity could be detected between young and old rats. Several hypotheses about the species difference were reviewed. Young and old rats, however, did show several differences in other sleep parameters which parallel those observed in humans. These age-related changes were a moderate decrease in the percent of total sleep time spent in paradoxical sleep, a decrease in the length of sleep bouts, an increase in the number of sleep bouts, and a decrease in the amplitude of the diurnal rhythm of sleep.

Muscarinic supersensitivity: a possible model for the sleep disturbance of primary depression?

Abstract: The sleep changes induced in normal volunteers following the administration of scopolamine on 3 consecutive mornings resemble many of the abnormalities observed in the sleep of patients with primary depression: increased sleep latency and reduced rapid eye movement (REM) latency, total sleep time, and sleep efficiency. Furthermore, in a multivariate discriminant analysis—previously shown to distinguish the sleep records of depressed patients from those of normal controls and insomniac patients—the records from baseline nights were selected as normal and those after scopolamine as predominately depressed. Those observations suggest to us that muscarinic supersensitivity in normals may function as a pharmacological model for the sleep disturbances of depression.

The relationship between stage III + IV + REM sleep and arousals with migraine.

Abstract: SYNOPSIS Three studies are presented investigating the relationship between sleep stages and the onset of migraine on awakening. Study I consists of the polygraphic recording of daytime naps in patients who suffer from sleep-precipitated migraine. All headache naps contained Stages III, IV or REM Sleep. The second study is that of serotonin levels during napping in which serotonin levels were stable during naps in which only Stages I and II were recorded. During naps when Stages III, IV or REM Sleep were recorded, there was considerable variation in serotonin levels. The final study is that of nocturnal sleep periods associated with morning awakening with headache or the onset of headache within 1 hour. The results of this study show an association between nights of increased Stage III + IV + REM sleep and those mornings when headaches occur.

Five variations of sleep deprivation in a depressed woman.

Abstract: Systematic variation in aspects of the sleep-wakefulness cycle of a depressed woman showed that recovery occurred reliably after 19 to 20 hours sustained wakefulness, unrelated to diurnal rhythm. Depression returned during as little as 15 minutes sleep. The effect of sleep deprivation was a specific response, probably unrelated to REM sleep.

Effects of Sleep Deprivation on Memory and Sleep Latencies in Connection with Repeated Awakenings From Sleep

Abstract: Twelve subjects were kept awake 64 hrs. During baseline and recovery sleep, subjects were given a simple memory task. The subjects were awakened 3 times each night during slow-wave sleep and shown 4 playing cards. Approximately 90 min later the subjects were again awakened and tested for retention of the previous cards and given 4 new cards to learn. This procedure was repeated 3 times each night and upon awakening the following morning. On the recovery night recall was reduced, slow-wave sleep was lengthened, sleep latency was shortened, and body motility was reduced. It was suggested that the reason for the poorer recall was deeper sleep induced by the sleep deprivation.

Linguistic organization and cognitive implications of REM and NREM sleep-related reports.

Abstract: Verbal reports related to REM and NREM sleep were subjected to syntactic (taking Chomskian standard theory as model) and pragmatic analysis (pause distribution within and between kernel sentences). Both in REM and NREM-verbal reports descriptions of the mental experience during sleep were syntactically correct and indicated little difficulty in lexical choice and little emotion. Even though the strategy appears to be the same (sequential) in both cases, the retrieval of content appears to be more difficult after NREM than after REM sleep. Perhaps different degrees of content consolidation in memory occur during the two types of sleep.

Type A behavior and normal habitual sleep duration

Abstract: The responses of 361 college students to the Jenkins Activity Survey and a self-report sleep questionnaire were used to demonstrate an inverse relationship between normal habitual sleep duration and level of Type A behavior. The possibility that patterns of sleep may be implicated in the development of Type A behavior in some individuals was considered.