REM Time Research Articles

Reliability of sleep measures.

ABSTRACTThe reliability of sleep measures was calculated over two nights (and within the nights) for 20 young adult males. Percent time in stages 1, 2, 3, and 4, percent movement time, number of movements, and number of stage changes were significantly correlated between Ss over nights. The percent REM time and REM cycle duration were not significantly correlated over nights. Within Ss, the length of the REM period had a significant negative correlation with the length of the preceding NREM period but not with the following NREM period. These data raise questions as to the use of the standard sleep measures as reliable human traits in young male adults.

Chlorpromazine and Sleep in Psychiatric Patients

The effect of chlorpromazine on nine patients with sleep disturbance was investigated. The results showed that chlorpromazine given at bedtime coincided with a marked increase in actual sleep time as exemplified by a significant decrease in intermittent wakefulness. Total REM time was increased proportionately to the increase in actual sleep. In a more extensive study in four patients, it was found that the administration of daytime chlorpromazine (100 mg) had no direct effect on sleep as compared to placebo. In contrast, bedtime chlorpromazine was associated with significant changes in various sleep parameters. That the time course of chlorpromazine administration is responsible for the differential effect on sleep is supported by the preliminary investigation with plasma chlorpromazine levels.

Sleep characteristics of the human aged female

The sleep of ten normal elderly women, aged 66 to 87 years (mean age, 76.7) was studied for four or five nights each. The mean REM percentage was 18.0; total REM time, 70 minutes; and mean REM period length, 18 minutes. This amount of REM sleep was not statistically different from the amount previously reported for the elderly male. The elderly male, as compared to the female, had significantly more first NREM periods shorter than 45 minutes. It was hypothesized that this may reflect slight brain changes in the male, not yet evident for the female. As previously reported for the male, REM sleep was quite markedly reduced in the oldest (aged 87 years) subject of the sample.

Longitudinal studies of the effect of monoamine oxidase inhibitors on sleep in man.

Monoamine oxidase inhibitors suppressed REM sleep during longitudinal sleep studies in four subjects. While the REM suppression occurred during maximum dosages, one normal subject showed an increase in REM time during the initial phase of drug administration. One patient had a marked REM compensation after the drug was discontinued. There were no consistent changes in Non-REM sleep. Monoamine oxidase inhibition was measured by plasma and platelet studies, as well as by 24-hour urinary tryptamine levels.

Selective REM sleep deprivation and compensation phenomena in the rat

This study was undertaken to assess the effectiveness of alternative methods and durations of REM sleep deprivation with rats, and to explore the feasibility of suitable controls. A total of 24 chronically implanted rats on an 8 h schedule were monitored for 3 consecutive days to determine basal amount of REM sleep. All animals were then subjected to one of four control or experimental conditions for either 3 or 6 days, followed by 3 consecutive days of recovery sleep. Water tank deprivation, using a small pedestal, appeared the equivalent of a more traditional arousal method of depriving REM sleep. Neither control arousals during NREM sleep nor the water tank control procedure utilizing a large pedestal, produced substantial deprivation. Negligible differences were found between 3 and 6-day deprived rats in compensation for lost REM time on recovery days, suggesting a ‘plateau’ effect. Other measures suggest that ‘intensity’ changes may account for additional compensation beyond the plateau of increased REM sleep time.

All-night sleep recordings of chronic schizophrenics in remission

Summary 1. A group of 13 chronic male schizophrenics nearing remission and 7 male control subjects were studied with all-night sleep recordings for 3 to 5 consecutive nights. 2. The patient group tended to show increased REM time, increased REM percentage, increased eye movements during REM, failure to suppress tonic EMG activity during REM, lack of the “first night effect,” and shorter REM latency periods. 3. These results and the results of other studies were discussed in relation to the hypothesis that REM sleep deprivation plays some role in the development of psychosis.

The effect of partial REM sleep deprivation and delayed recovery

Four young adult subjects each slept ten consecutive nights in the laboratory without awakenings. The mean nightly REM sleep time was calculated for each subject and used as the baseline value for futher procedures. Two subjects were allowed 75 per cent of their baseline REM sleep time for nineteen consecutive nights and slept without disturbance for the next five (recovery) nights. The first recovery nights were 54 per cent and 13 per cent respectively above the baseline with a more or less exponential decline to the basal level on subsequent nights. The compensatory rises in REM time were compatible with what might have been expected following five nights of complete deprivation and suggest that partial REM deprivation has a cumulative effect roughly proportional to the degree of partial deprivation. The other two subjects underwent complete REM sleep deprivation for five consecutive nights followed by five nights upon which REM sleep time was held to the baseline level. The next five nights were undisturbed and the REM sleep fraction was elevated 100 per cent and 66 per cent respectively above the baseline. These results suggest that the REM sleep deprivation effect can be reversed only by extra amounts of REM sleep and will persist if such compensation does not take place.

The effect of ethyl alcohol on electroencephalographic sleep cycles in cats

EEGs taken from four sleeping cats for three control and four alcohol consecutive nights show that if 1 gm ethanol/kg body weight is administered 15 min. prior to sleep, Stage 1 REM time decreases from control values the first two alcohol nights but returns to control levels on the third and fourth alcohol nights. This pattern of change in REM time is the same as that found in humans. The REM time pattern is effected by a change in length rather than in numbers of REM periods. These data support the use of cats in establishing a mechanism for REM sleep which can be extrapolated to humans.

The effect of ethyl alcohol on man's electroencephalographic sleep cycle

This study indicates that 1 g of ethyl alcohol per kg of body weight administered before sleep exerts a systematic effect on EEG sleep patterns. In three human subjects over 13 consecutive nights (4 control, 5 alcohol, and 4 recovery nights), the most consistent pattern of change from night to night was seen in stage I REM. On the first night of alcohol the mean REM time dropped from the mean control value and over the next four consecutive nights on ethyl alcohol increased steadily to a peak value on the fifth night of alcohol. In four recovery nights REM time dropped back to control levels. This change in REM occurs in the first half of the night, when CSF alcohol levels are at their maximum concentration, and during the second half of the night. Latency or time to the first REM is constant in control and post-alcohol nights but varies unsystematically during nights of alcohol administration. Stages III and IV remain constant while stage II “absorbs” the shifts demonstrated in stage I.