Waking and sleeping最新文献

Lumbar cerebrospinal fluid (CSF) of seven healthy male volunteers contains detectable levels of arginine vasotocin (AVT) when CSF was removed after awakening from rapid eye movement (REM) sleep. No detectable levels of AVT were found in the CSF of the same subjects when CSF WAS removed after awakening from non rapid eye movement (NREM) sleep. The amount of AVT detected in CSF after REM sleep was significantly higher if the subjects experienced vivid and emotive dreams. The present results provide the first evidence for a REM sleep dependent release of AVT into CSF of man.

Sleep of 6 depressed patients with hypersomnia was studied during their depressed phase and their remitted phase using 24-h polygraphic recording. Nine normal subjects were studied as the controls. The latency to sleep onset of the depressed patients was significantly shorter than that of the remitted patients and that of the control subjects. The total sleep time of the depressed patients was significantly longer than that of the remitted patients as well as that of the controls. This increase in sleep time of the depressed patients was mainly due to the increased sleep in day time. The intervals between sleep onset and start of each sleep stage, the relative percentage of individual sleep stages, REM latency and REM density of the depressed patients were not significantly different from those of the remitted patients.

The EEG records of 15 younger females and 40 older females were analyzed in an effort to reevaluate the effects of the first night of laboratory sleep, and to determine to what extent age may be a variable in the First Night Effect. These records substantiate earlier findings that sleep latency is longer, there is more wakefulness, and the REM cycle is disrupted on the first night of laboratory sleep. In addition, there is some evidence that older subjects show a greater First Night Effect. These effects adapt out by the second night of sleep.

The operational value of measuring paradoxical sleep (PS) as a percentage of total sleeping time has been questioned. The purpose of this study was to determine the interactions between the variations in hormonal secretions and paradoxical sleep in women of different age-groups. Three parameters were utilized: REM-percent, REM-density and the eye movement frequencies. The distribution of the time-intervals between the oculomotor signals as indicated by the ratio of the higher to the lower eye movement frequencies gives a clue as to the significance of the spatio-temporal organization of the brain-signals during paradoxical sleep. This notion introduces an internal temporal and dynamic dimension in the concept of REM or Paradoxical Sleep. From our results it appears that the changes in the ratio between the different types of oculomotor discharges are a function not only of hormonal fluctuations but also of age. This point of view opens a new possibility of interpreting the results.

Systemic administration of GABA-transaminase inhibitors, gamma-acetylenic GABA (100 mg/kg) or gamma-vanylic GABA (1200 mg/kg) produces behavioral picture of somnolence accompanied by EEG hypersynchronisation reminiscent of electrographic signs of petit mal epilepsy. Similarly, systemic administration of GABA antagonist, Picrotoxin (3--4 mg/kg) produces a short lasting period of sedation preceding the development of myoclonic jerks which is also accompanied by Wave-spike discharges. The role of GABA in sleep control is discussed. Although the area is not ready for firm conclusions, the results suggest that hyperactivity of GABA-ergic system as well as its hypoactivity could mediate pathological somnolence associated with different forms of epilepsy.

Arginine vasotocin (AVT) or placebo were subcutaneously administered to 4 men at 22.00 and 01.00 h, along four nights, and polygraphic recordings were performed between 22.00 and 02.00 h during sleep. AVT significantly increased only the amount of rapid eye movement (REM) sleep (p less than 0.05), but did not influence the latency of the first REM sleep period. This effect of AVT was not dose dependent in the range between 2 and 12 microgram AVT. AVT or placebo were also intravenously injected or perfused to 10 normal adult subjects, at different times of the day, under clinical control. Doses between 2 microgram perfused 4 h and 12 microgram perfused 30 min, did not produce clinical signs of sleep. It is suggested that AVT is not a blood factor for inducing of slow waves sleep (SWS) or REM sleep in humans.

Basing themselves on an analysis of data cited by other researchers and the results of their own investigation, conducted on man and animals, the authors disclose that sleep changes are determined by the type of behavioural reaction to emotional stress: the behaviour that includes components of search activity directed at changing the situation is accompanied by a reduction of REM sleep time; renunciation of search, as in the cases of passive avoidance, neurotic anxiety and depression, is attended by an increase in REM sleep requirement. Presumably, the function of REM sleep is to compensate for renunciation of search in the waking period. The authors suggest a method of appraising the character of reaction to stress by sleep changes--calculation of the time ratio of REM sleep to delta-sleep in the first two cycles.

The structural and temporal characteristics of tonic variation among electrophysiological measures during sleep are examined from the point of view of sleep stage scoring procedures and the digital quantification and statistical analysis of these measures. Sleep stage scoring procedures are nominally scaled and therefore less able to index structural and temporal characteristics than are measures derived from digital methods of quantification having the properties of interval or ratio scales. These arguments are illustrated using principal components analysis to describe the structure of tonic covariation among 36 variables derived from the computer analysis of EEG, EMG, and EOG. Three components resulting from the analysis are tentatively named 'slow-fast', 'hemispheric-shift' and 'eyes-activation'. They appear across variations in experimental manipulations such as night time awakenings and also across differences in age and species. The periodic characteristics of the vectors associated with the three components are specified by means of the Fast Fourier transform in combination with digital low pass and band pass filtering. Cycles are found which are both slower and faster than the paradigmatic 90 min ultradian rhythm. These results indicate that currently available techniques of digital and statistical analysis provide new possibilities for research on the electrophysiology and psychophysiology of sleep.