Epstein-Barr virus lacking glycoprotein gp42 can bind to B cells but is not able to infect

Sleep consists of two complex states--NREM and REM sleep--and disturbances of the boundaries between the states of sleep and wakefulness may result in violence. We investigated our population for reports of violence associated with sleep. REM behavior disorder is rarely associated with injury to the sufferer or others. NREM sleep related nocturnal wandering associated with self-inflicted injuries has variable etiologies. In the elderly, it is associated with dementia. In young individuals, it may be associated with mesio-temporal or mesio-frontal foci and an indication of a complex partial seizure. It also may be related to abnormal alertness and is associated with excessive daytime sleepiness, micro-sleeps, and hypnagogic hallucinations in sleep disorders such as narcolepsy or sleep disordered breathing.     

Use of dynamic two-dimensional transesophageal echocardiography for renal cell carcinoma with cavoatrial tumor thrombus

Previous investigations involving continuous blood pressure (BP) monitoring have shown an important alteration of the 24-hour BP profile in patients with obstructive sleep apnea syndrome (OSAS). We investigated the impact of REM sleep on the 24-hour BP cycle in 16 severe OSAS male patients (mean respiratory disturbance index = 66 +/- 16 events/hour of sleep), with hypertension (mean BP 162 +/- 21/105 +/- 11 mmHg World Health Organization (WHO) protocol). Two successive nights of polysomnography were performed, and arterial BP was monitored continuously during the second 24-hour period after brachial artery cannulation. During the daytime, subjects were kept awake and supine. At 3 p.m. BP was continuously monitored during quiet supine wakefulness for 20 minutes. Systolic, diastolic and mean BP and heart rate (HR) were analyzed and tabulated in mean values of 5 minute segments. Sleep/wake information were correlated with cardiovascular variables. Each uninterrupted REM sleep period was identified and comparison between the period of quiet supine wakefulness and REM sleep HR and BP values was performed. 8 OSAS patients presented a normal drop of the mean arterial BP during the nocturnal REM sleep periods compared to quiet supine wakefulness (mean value = -10.8 +/- 7.3 mmHg) ("dippers") while the other 8 subjects ("REM sleep non dippers"), revealed an elevated mean arterial BP during REM sleep (mean value = 18.9 +/- 10.9 mm Hg). The absence of the normal circadian BP dip seen during the nocturnal sleep period is considered as an indication of vascular risk. The REM sleep non dipping may play a role in this risk.     

Sleep architecture in a canine model of obstructive sleep apnea

Obstructive sleep apnea (OSA) causes recurrent sleep disruption that is thought to contribute to excessive daytime sleepiness in patients with this disorder. The purpose of this study was to determine the specific effects of OSA on overall sleep architecture in a canine model of OSA. The advantage of this model is that sleep during long-term OSA can be compared to both normal sleep before OSA and recovery sleep after OSA. Studies were performed in four dogs in which sleep-wake state was monitored continuously by a computer that received telemetered EEG and EMG signals. Whenever sleep was detected, the computer sent a signal to close a valve through which the dog breathed; when the dog awoke the occlusion was released. In each dog, data were analyzed from 4 consecutive nights in three phases: a control phase before induction of OSA, a phase during long-term OSA (mean = 85 days, apnea index = 59/hour), and a recovery phase after cessation of OSA. During recovery there was a significant increase in the amount of rapid-eye-movement (REM) sleep compared to the OSA phase (p < 0.01), as well as significant increases in sleep efficiency and decreases in wakefulness (p < 0.01), similar to that reported in OSA patients. The REM rebound during recovery, however, could not be attributed to overall REM deprivation since the amount of REM sleep during the OSA phase was not different from the control phase (p = 0.708). This finding suggests that REM rebound during recovery from OSA is not the result of an overall REM sleep deficit per se. Rather, repeated sleep disruption due to the effects of repetitive apneas and hypoxia may lead to an increased REM sleep drive that manifests itself as a REM sleep rebound during recovery sleep after OSA.     

Acoustic hallucinations as a symptom of a REM sleep-associated parasomnia

This 52-year-old man suffered from auditory hallucinations that occurred during brief episodes of sleep paralysis at the end of REM sleep periods. During these episodes the patient experienced a dissociated state of consciousness with REM sleep intrusions into wakefulness. The occurrence of this mixed state, and of excessive sleep-onset REM periods during daytime polysomnography (MSLT = Multiple Sleep Latency Test), point to a disorder of REM sleep generation. The existence of narcolepsy could be ruled out. The observation of REM sleep-associated hallucinations has been reported earlier. In the presented polysomnographic sleep studies the existence of a REM sleep associated parasomnia characterised by hallucinations and sleep paralysis could be confirmed.     

Sleep-arousal dissociation in a case of hypersomnia

INTRODUCTION: Dissociated sleep-arousal states are clinical and experimental phenomena which represent mixed forms of the three stages of this cycle (arousal, NREM sleep and REM sleep). CLINICAL CASE: We describe the case of a man who presented with a history of excessive diurnal somnolence for the previous 5 years. He also had symptoms of sleep paralysis, hypnagogic hallucinations, automatic behavior and excessive movements during sleep. He had had no episodes of loss of muscle tone; MR was normal; HL DR2 and DQwl antigens were negative; two polisomnographic and a Multiple Latency Sleep test showed: 1. Absence of respiratory disorders. 2. Normal latency of REM sleep. 3. Periods of dissociated sleep (REM without atonia and arousal with atonia), and 4. An average sleep latency of 3.2 minutes and absence of REM periods. CONCLUSION: This case adds a new type of dissociated sleep state which may accompany the disorder known as hypersomnia without REM periods.     

Monotremes and the evolution of rapid eye movement sleep

Early studies of the echidna led to the conclusion that this monotreme did not have rapid eye movement (REM) sleep. Because the monotremes had diverged from the placental and marsupial lines very early in mammalian evolution, this finding was used to support the hypothesis that REM sleep evolved after the start of the mammalian line. The current paper summarizes our recent work on sleep in the echidna and platypus and leads to a very different interpretation. By using neuronal recording from mesopontine regions in the echidna, we found that despite the presence of a high-voltage cortical electroencephalogram (EEG), brainstem units fire in irregular bursts intermediate in intensity between the regular non-REM sleep pattern and the highly irregular REM sleep pattern seen in placentals. Thus the echidna displays brainstem activation during sleep with high-voltage cortical EEG. This work encouraged us to do the first study of sleep, to our knowledge, in the platypus. In the platypus we saw sleep with vigorous rapid eye, bill and head twitching, identical in behaviour to that which defines REM sleep in placental mammals. Recording of the EEG in the platypus during natural sleep and waking states revealed that it had moderate and high-voltage cortical EEGs during this REM sleep state. The platypus not only has REM sleep, but it had more of it than any other animal. The lack of EEG voltage reduction during REM sleep in the platypus, and during the REM sleep-like state of the echidna, has some similarity to the sleep seen in neonatal sleep in placentals. The very high amounts of REM sleep seen in the platypus also fit with the increased REM sleep duration seen in altricial mammals. Our findings suggest that REM sleep originated earlier in mammalian evolution than had previously been thought and is consistent with the hypothesis that REM sleep, or a precursor state with aspects of REM sleep, may have had its origin in reptilian species.     

Ultradian rhythms in hydromineral hormones

The maintenance of hydromineral homeostasis depends on the coordinated action of arginine vasopressin (AVP), atrial natriuretic peptide (ANP), the renin-angiotensin-aldosterone system and other recently identified endocrine or paracrine hormones. Several reports have pointed out the changes in urinary excretion and osmolality during the sleep-wake cycle and the rapid eye movement (REM)-non(N)REM sleep cycles. No such changes occur for ANP levels which have a flat profile over 24 h. The pulsatile fluctuations of AVP are described as random. The ultradian rhythm of plasma renin activity (PRA) depends on the regularity of the REM-NREM sleep cycles and the nocturnal curves reflect all disturbances in the internal sleep structure. A study with a shift in the normal sleep time clearly demonstrated that both PRA and aldosterone oscillations are sleep-stage dependent. These hormones could account for the ultradian variations in renal function. The nocturnal oscillations in sympathovagal balance may play an additional role. It is suggested that a central generator synchronizes endocrine, renal, autonomic and sleep processes.     

Arousal responses to inspiratory resistive loading during REM and non-REM sleep in normal men after short-term fragmentation/deprivation

The arousal response to inspiratory resistive loading in normal men is known to be high during REM sleep compared to non-REM sleep. We investigated whether we could observe the same pattern, i.e. brisk arousal from REM sleep compared to non-REM sleep, in normal subjects who had undergone short-term sleep fragmentation/deprivation prior to the investigation. The arousal response to the repeated application of an external inspiratory resistance of 25 cm H2O/l/s was determined during REM and non-REM sleep in 10 healthy men after a single night with 4 hours of acoustically fragmented sleep. The percentage of arousals to non-arousals occurring within 2 minutes of the load application was significantly higher during REM sleep than during either of the non-REM sleep stages 2 and 3/4 and decreased significantly from stage REM to stage 2 and from stage 2 to stage 3/4. The mean time to arousal in REM was significantly shorter than in non-REM stage 3/4. The duration of sleep (comparing the results of the first with the second half of the sleep period time) did not modify the arousal response in stages 2 and 3/4. Despite short-term sleep fragmentation/deprivation the night before the study, the arousal response to external inspiratory resistive loading was brisker during REM than non-REM sleep in the healthy subjects studied. The responses were of the same magnitude as those induced in prior studies without pretest sleep disturbance. This is different from what is seen in patients with sleep apnea, where breathing disorders are worst during REM sleep and sleep fragmentation/deprivation leads to rapid deterioration of arousal responses to the spontaneously occurring airway occlusions.     

Acute von Willebrand factor secretion from the endothelium in vivo: assessment through plasma propeptide (vWf:AgII) Levels

STUDY OBJECTIVES: Patients with coronary heart disease (CHD) and obstructive sleep apnea may have an increased cardiac risk due to nocturnal myocardial ischemia triggered by apnea-associated oxygen desaturation. Sleep structure in patients with obstructive sleep apnea is fragmented by activation of the central nervous system (CNS) (arousal) due to obstructive apneas. Nocturnal myocardial ischemia may lead to activation of the CNS as well. PATIENTS: Fourteen patients with obstructive sleep apnea and CHD disease and seven patients suffering from obstructive sleep apnea without CHD were studied. Overnight sleep studies and simultaneous six-lead ECG recordings were performed. In addition, sleep studies and ECG recordings were performed with administration of a sustained-release nitrate in these patients in a double-blinded crossover design. RESULTS: Analysis of three nights' recordings revealed 144 episodes of nocturnal myocardial ischemia in six subjects. Five patients had underlying CHD and one patient exhibited diffuse wall defects of the coronary arteries; also, 85.4% of ischemic episodes were concomitant with apneas and oxygen desaturation > 3%, and 77.8% of ischemic episodes occurred during rapid eye movement (REM) sleep, although total amount of REM sleep was only 18% of total sleep time. Mean oxygen saturation was significantly lower (p < 0.05) during apnea-associated ischemic episodes than during nonapnea-associated ischemia (77.3% vs 93.1%). Nitrate administration did not reduce ischemic episodes. Sleep architecture (macrostructure) exhibited a reduction in sleep stages non-REM 3 and 4 and REM sleep. Comparing the microstructure of sleep (arousals) within episodes with and without ischemia but similar criteria like sleep stage, apnea activity, and oxygen saturation, we found significantly more (p < 0.01) and severe (p < 0.001) arousals during periods with myocardial ischemia than during control episodes. In addition, microstructure of sleep was disturbed by myocardial ischemia itself in absence of apneas. CONCLUSION: It is concluded that patients with CHD and obstructive sleep apnea are endangered by apnea-associated ischemia and that these ischemic episodes lead to activation of the CNS and additional fragmentation of sleep. Patients with nocturnal ischemia should be screened for underlying sleep apnea even if nitrate therapy fails.     

Influence of sleep states on laryngeal and abdominal muscle response to upper airway occlusion in lambs

This study was aimed at describing abdominal and laryngeal muscle responses to upper airway occlusion (UAO) in early life and the effect of sleep states on these responses. Twelve nonsedated, 9-26-d-old lambs were studied. We simultaneously recorded 1) airflow (pneumotachograph + face mask); 2) sleep states (electrocorticogram and electrooculogram); 3) abdominal muscle (external obliquus) electromyogram (EMG); and 4) glottic constrictor (thyroarytenoid) and dilator (posterior cricoarytenoid and cricothyroid) muscle EMGs. The pneumotachograph was repeatedly occluded for 15-30 s in wakefulness and natural sleep. We analyzed 90 occlusions during wakefulness (11 lambs), 28 during non-rapid eye movement (nREM) sleep (six lambs), and 23 during rapid eye movement (REM) sleep (five lambs). A phasic expiratory external obliquus EMG was present during baseline and progressively increased throughout UAO in wakefulness and nREM sleep, but not in REM sleep. Phasic thyroarytenoid EMG progressively increased during inspiratory efforts throughout UAO in wakefulness and nREM sleep, paralleling the increase in glottic dilator (posterior cricoarytenoid and cricothyroid) EMG. In contrast, glottic muscle response to UAO in REM sleep was severely blunted or disorganized by frequent swallowing movements. We conclude that UAO triggers complex and coordinated laryngeal and abdominal muscle responses during wakefulness and nREM sleep in lambs; these responses are largely absent, however, in REM sleep. These unique results, together with the defective arousal response in REM sleep, suggest that vulnerability to airway occlusion could be increased during REM sleep in early life. Possible implications for understanding severe postnatal apneas are discussed.     

REM sleep parasomnia

The parasomnias consist of a heterogenous group of sleep behaviour disorders with different etiologies and various symptomatologies. By employing polysomnography and the simultaneous video recording of behaviour during sleep, it is possible to associate behavioral disturbances during sleep with specific sleep stages. In the present case study, a patient with a REM (rapid eye movement) sleep behaviour disorder is discussed. This rare form of parasomnia is characterized by motor enactment of vivid and striking dreams. Underlying disease in the present case involved bilateral lacunar ischemic infarcts in the brain stem. Under the combined psychotropic medication of carbamazepine and amitriptyline, the behaviour disorder during REM sleep remitted markedly.     

Contributions of the pedunculopontine region to normal and altered REM sleep

The pedunculopontine (PPN) region of the upper brainstem is recognized as a critical modulator of activated behavioral states such as wakefulness and rapid eye movement (REM) sleep. The expression of REM sleep-related physiology (e.g. thalamocortical arousal, ponto-geniculate-occipital (PGO) waves, and atonia) depends upon a subpopulation of PPN neurons that release acetylcholine (ACh) to act upon muscarinic receptors (mAChRs). Serotonin's potent hyperpolarization of cholinergic PPN neurons is central to present working models of REM sleep control. A growing body of experimental evidence and clinical experience suggests that the responsiveness of the PPN region, and thereby modulation of REM sleep, involves closely adjacent glutamatergic neurons and alternate afferent neurotransmitters. Although many of these afferents are yet to be defined, dopamine-sensitive GABAergic pathways exiting the main output nuclei of the basal ganglia and adjacent forebrain nuclei appear to be the most conspicuous and the most likely to be clinically relevant. These GABAergic pathways are ideally sited to modulate the physiologic hallmarks of REM sleep differentially (e.g. atonia versus cortical activation), because each originates from a functionally unique forebrain circuit and terminates in a unique pattern upon brain stem neurons with unique membrane characteristics. Evidence is reviewed that changes in the quality, timing, and quantity of REM sleep that characterize narcolepsy, REM sleep behavior disorder, and neurodegenerative and affective disorders (depression and schizophrenia) reflect 1) changes in responsiveness of cells in the PPN region governed by these afferents; 2) increase or decrease in PPN cell number; or 3) mAChRs mediating increased responsiveness to ACh derived from the PPN. Auditory evoked potentials and acoustic startle responses provide means independent from recording sleep to assess pathophysiologies affecting the PPN and its connections and thereby complement investigations of their role in affecting daytime functions (e.g. arousal and attention).     

Effect of sleep on changes in breathing pattern accompanying sigh breaths

We studied the effect of sleep on the characteristics of sigh breaths and the associated changes in breathing pattern in breaths following spontaneous sighs in 4 unrestrained dogs with an intact upper airway. The sigh breath was characterized by its large tidal volume (VT), long TI and TE in comparison with the control breath. The volume of the sigh breath was larger in awake sighs than in those recorded during non-REM (NREM) and REM sleep. The strength of Hering-Breuer reflex as determined by duration of the post-sigh apnea was similar in NREM and REM sleep. Sighs occurring during wakefulness, NREM and REM sleep were associated with augmented activity of the parasternal muscles during inspiration, and a persistent tonic abdominal muscle activity during the expiratory period. Breathing pattern in the post-sigh period was characterized by a smaller VT and longer TE in the first post-sigh breath in all sleep states (compared with the control breath), but the pattern returned to control level within the second or third post-sigh breath in both NREM and REM sleep. Sighs did not precipitate periodic breathing or other forms of abnormal breathing patterns in either wakefulness or sleep. We conclude that the respiratory control mechanisms stabilizing breathing after a sigh in the awake dog are intact in NREM and REM sleep.     

An evaluative study of the short-term effects of once-daily, sustained-release theophylline on sleep in nocturnal asthmatics

OBJECTIVE: To examine the effects of once-daily, sustained-release theophylline on sleep patterns in nocturnal asthmatics. DESIGN: Double-blind, randomised, cross-over, placebocontrolled trial over 22 days. Seven-day period to establish therapeutic levels of theophylline (11.8 +/- 3 mg/l); 8-day cross-over period of 4 days' placebo or theophylline; 7-day baseline period. Electrophysiological sleep patterns, overnight bronchoconstriction and arterial O2 saturation monitored on nights 7, 11 and 15. SETTING: Sleep Laboratory, Medical School, University of the Witwatersrand. PATIENTS: Twelve volunteers who met the criteria for asthma, had previously used theophylline, were clinically stable and had a history of nocturnal awakenings caused by asthma were enrolled. OUTCOME MEASURES: Sleep-onset latency (SOL), within-sleep wakefulness (WSW), rapid eye movement sleep (REM), slow-wave sleep (SWS), peak expiratory flow rate (PEFR) and arterial oxygen saturation. RESULTS: SOL increased on theophylline--12 minutes (range 7-9 minutes) compared with placebo--6 minutes (range 3-11 minutes); WSW increased from 33 minutes (range 17-66 minutes) on placebo to 72 minutes (range 35-150 minutes) on theophylline. REM sleep was unaltered. SWS decreased in 10-12 patients, but this difference was not significant. Early morning PEFR was significantly better on theophylline in all study limbs. CONCLUSION: Our findings show that while once-daily, sustained-release theophylline improves bronchodilation in nocturnal asthmatics, it increases nocturnal wakefulness and decreases sleep efficiency during short-term treatment. This may, however, not be a long-term effect.     

Enhanced slow wave sleep in patients with prolactinoma

Bidirectional interactions between nocturnal hormone secretion and sleep regulation are well established. In particular, a link between PRL and rapid eye movement (REM) sleep has been hypothesized. Short-term administration of PRL and even long-term hyperprolactinemia in animals increases REM sleep. Furthermore, sleep disorders are frequent symptoms in patients with endocrine diseases. We compared the sleep electroencephalogram of seven drug-free patients with prolactinoma (mean PRL levels 1450 +/- 1810 ng/mL; range between 146 and 5106 ng/mL) with that of matched controls. The patients had secondary hypogonadism but no other endocrine abnormalities. They spent more time in slow wave sleep than the controls (79.4 +/- 54.4 min in patients vs. 36.6 +/- 23.5 min in controls, P < 0.05). REM sleep variables did not differ between the samples. Our data suggest that chronic excessive enhancement of PRL levels exerts influences on the sleep electroencephalogram in humans. Our result, which seems to be in contrast to the enhanced REM sleep under hyperprolactinemia in rats, leads to the hypothesis that both slow wave sleep and REM sleep can be stimulated by PRL. These findings are in accordance with reports of good sleep quality in patients with prolactinoma, which is in contrast to that of patients with other endocrine diseases.     

Chronic headaches and sleep disorders

BACKGROUND: Headaches and sleep problems are common complaints in the daily practice of the general practitioner. Since the relationship between headaches and sleep complaints is complex, clear models of interaction are needed for adequate diagnosis and treatment. METHODS: All subjects, successively seen in a headache clinic during a defined period, were subdivided based on the time of onset of cephalalgia. Subjects who reported onset of headache on a long-term basis, during the nocturnal or early morning (before final awakening) period, were systematically studied by a headache clinic and a sleep disorders center. This subgroup represented 17% of the total headache group. RESULTS: Although the results of the headache clinic study did not differentiate this subgroup from the other patients, the sleep disorders center's interviews and questionnaires demonstrated a significant impact of the sleep disorders on headache and daytime function. Nocturnal monitoring during sleep identified specific sleep disorders in 55% of the subjects with onset of headache during the nocturnal sleep period. Follow-up after treatment of the sleep disorder showed that all subjects with an identifiable sleep disorder reported either an improvement or absence of their headache. The subjects identified with periodic limb movement syndrome were mostly those who reported only an improvement in their sleep and still needed treatment for their headaches. The question of the interaction and association of sleep-related headache and periodic limb movement syndrome is unresolved. CONCLUSION: Headaches occurring during the night or early morning are often related to a sleep disturbance.     

REM sleep behavior disorders in multiple system atrophy

We report the results of clinical and polysomnographic investigations on 39 consecutive multiple system atrophy (MSA) patients. Twenty-seven patients (69%) reported nocturnal motor paroxysmal episodes related to dreams, suggesting the clinical diagnosis of REM sleep behavior disorder (RBD). In 12 of them (44%), RBD preceded the clinical onset of the disease by more than 1 year. In seven (26%), the RBD onset was concomitant with and in eight (30%) was at least 2 years after the appearance of motor or autonomic symptoms. On polysomnographic recordings, 35 of 39 MSA patients (90%) had RBD. Other polysomnographic findings included nonclinical obstructive sleep apnea in 6 patients, laryngeal stridor in 8 patients, and periodic limb movements during sleep in 10 patients. Our data show that RBD represents the most common clinical sleep manifestation and polysomnographic finding in patients with MSA. RBD can frequently herald the appearance of other MSA symptoms by years. Extended polysomnographic montages are recommended in MSA sleep studies.     

The influence of a heavy thermal load on REM sleep in the rat

This study was carried out in order to further test the hypothesis that the occurrence of REM sleep in the rat in the form of episodes separated by long intervals (single REM sleep episodes) and by short intervals (sequential REM sleep episodes) is differently influenced by changes in both sleep and ambient related processes. Rats were studied during the exposure to Ta -10 degrees C for 24 or 48 h and during a 12 h recovery period at laboratory Ta (23 degrees C) following either the first or the second 24 h of cold exposure. The exposure to such a low Ta induced an almost complete abolition of REM sleep which was followed, during recovery, by a marked REM sleep rebound. However, in spite of the larger REM sleep deprivation, the REM sleep rebound was weaker following the 48 h-exposure than that following the exposure for 24 h. The increase in the amount of REM sleep during the recovery period was due to an increase in the amount of that occurring in the form of sequential episodes, whilst that in the form of single episodes did not change with respect to control levels. However, the occurrence of REM sleep in the form of sequential episodes was partially impaired during the REM sleep rebound observed in the recovery period following the 48 h-exposure. These results would suggest that the homeostatic regulation of physiological variables may conflict with that of REM sleep occurrence and that the degree of such a contrast is indicated, at low Ta, by the amount of REM sleep in the form of single episodes and, during the following recovery, by the amount of REM sleep in the form of sequential episodes.     

Cavitary necrosis complicating pneumonia in children: sequential findings on chest radiography

We tested the hypothesis that the obese (fa/fa) Zucker rat has a sleep organization that differs from that of lean Zucker rats. We used the polygraphic technique to identify and to quantify the distribution of the three main states of the rat: wakefulness (W), non-rapid-eye-movement (NREM), and rapid-eye movement (REM) sleep states. Assessment of states was made with light present (1000-1600), at the rats thermoneutral temperature of 29 degrees C. Obese rats, compared with lean ones, did not show significant differences in the total time spent in the three main states. Whereas the mean durations of W and REM states did not differ statistically, that of NREM did (P = 0.046). However, in the obese rats, the frequencies of switching from NREM sleep to W, which increased, and from NREM to REM sleep, which decreased, were statistically significantly different (P = 0.019). Frequency of switching from either REM or W state was not significantly different. We conclude that sleep organization differs between lean and obese Zucker rats and that it is due to a disparity in switching from NREM sleep to either W or REM sleep and the mean duration of NREM sleep.     

Effects of hypnotic induction and suggestions on nocturnal dreaming and thinking.

Examined the effects of hypnotic induction and types of suggestions on sleep mentation, using 77 Ss in a 2 * 3 factorial experiment. Immediately before going to sleep at night, 1/2 of the Ss were exposed to a hypnotic induction and 1/2 were not, and all Ss were given either authoritative, permissive, or no suggestions to think and dream that night on a specific topic. Ss reported their thoughts and dreams when awakened at sleep onset and during REM and NREM periods. The intricate findings indicate that hypnotic induction and types of suggestions exerted complex effects on nocturnal thinking and dreaming. Contents of the dreams were affected by an interaction between hypnotic induction and types of suggestions, and the hypnotic induction increased the number of nocturnal thoughts which pertained to the specified topic. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)