scholarly journals Low-Frequency Oscillations of Cortical Oxidative Metabolism in Waking and Sleep

1988 ◽  
Vol 8 (2) ◽  
pp. 215-226 ◽  
Author(s):  
Boris A. Vern ◽  
William H. Schuette ◽  
Boris Leheta ◽  
Vern C. Juel ◽  
Miodrag Radulovacki
Keyword(s):  
Blood Volume ◽  
Rem Sleep ◽  
Oxidative Metabolism ◽  
Redox State ◽  
Slow Wave Sleep ◽  
Cerebral Metabolism ◽  
Mean Amplitude ◽  
High Amplitude ◽  
State Transitions ◽  
Waking And Sleep

To study the changes in cortical oxidative metabolism and blood volume during behavioral state transitions, we employed reflectance spectrophotometry of the cortical cytochrome c oxidase (cyt aa3) redox state and blood volume in unanesthetized cats implanted with bilateral cortical windows and EEG electrodes. Continuous oscillations in the redox state and blood volume (∼9/min) were observed during waking and sleep. These primarily metabolic oscillations of relatively high amplitude were usually synchronous in homotopic cortical areas, and persisted during barbiturate-induced electrocortical silence. Their mean amplitude and frequency did not vary across different behavioral/EEG states, although the mean levels of cyt aa3 oxidation and blood volume during rapid eye movement (REM) sleep significantly exceeded those during waking and slow-wave sleep. These data suggest the existence of a spontaneously oscillating metabolic phenomenon in cortex that is not directly related to neuroelectric activity. A superimposed increase in cortical oxidative metabolism and blood volume occurs during REM sleep. Experimental data concerning cerebral metabolism and blood flow that are obtained by clinical methods that employ relatively long sample acquisition times should therefore be interpreted with caution.

scholarly journals Sounding It Out: Auditory Stimulation and Overnight Memory Processing

2021 ◽  
Author(s):  
Marcus O. Harrington ◽  
Scott A. Cairney
Keyword(s):  
Rem Sleep ◽  
Memory Consolidation ◽  
Slow Wave Sleep ◽  
Auditory Stimulation ◽  
Theta Oscillations ◽  
Neural Oscillations ◽  
Healthy Children ◽  
Factors Affecting ◽  
Memory Processing ◽  
Eeg Recordings

Abstract Purpose of Review Auditory stimulation is a technique that can enhance neural oscillations linked to overnight memory consolidation. In this review, we evaluate the impacts of auditory stimulation on the neural oscillations of sleep and associated memory processes in a variety of populations. Recent Findings Cortical EEG recordings of slow-wave sleep (SWS) are characterised by two cardinal oscillations: slow oscillations (SOs) and sleep spindles. Auditory stimulation delivered in SWS enhances SOs and phase-coupled spindle activity in healthy children and adults, children with ADHD, adults with mild cognitive impairment and patients with major depression. Under certain conditions, auditory stimulation bolsters the benefits of SWS for memory consolidation, although further work is required to fully understand the factors affecting stimulation-related memory gains. Recent work has turned to rapid eye movement (REM) sleep, demonstrating that auditory stimulation can be used to manipulate REM sleep theta oscillations. Summary Auditory stimulation enhances oscillations linked to overnight memory processing and shows promise as a technique for enhancing the memory benefits of sleep.

Regulation of cytochrome oxidase redox state during umbilical cord occlusion in preterm fetal sheep

2007 ◽  
Vol 292 (4) ◽  
pp. R1569-R1576 ◽  
Author(s):  
Laura Bennet ◽  
Vincent Roelfsema ◽  
Justin M. Dean ◽  
Guido Wassink ◽  
Gordon G. Power ◽  
...  
Keyword(s):  
Cytochrome Oxidase ◽  
Umbilical Cord ◽  
Redox State ◽  
Cerebral Oxygenation ◽  
Cerebral Metabolism ◽  
Electron Flow ◽  
Initial Response ◽  
Severe Hypoxia ◽  
Fetal Sheep ◽  
Severe Hypotension

The preterm fetus is capable of surviving prolonged periods of severe hypoxia without neural injury for much longer than at term. To evaluate the hypothesis that regulated suppression of brain metabolism contributes to this remarkable tolerance, we assessed changes in the redox state of cytochrome oxidase (CytOx) relative to cerebral heat production, and cytotoxic edema measured using cerebral impedance, during 25 min of complete umbilical cord occlusion or sham occlusion in fetal sheep at 0.7 gestation. Occlusion was followed by rapid, profound reduction in relative cerebral oxygenation and EEG intensity and an immediate increase in oxidized CytOx, indicating a reduction in electron flow down the mitochondrial electron transfer chain. Confirming rapid suppression of cerebral metabolism there was a loss of the temperature difference between parietal cortex and body at a time when carotid blood flow was maintained at control values. As occlusion continued, severe hypotension/hypoperfusion developed, with a further increase in CytOx levels to a plateau between 8 and 13 min and a progressive rise in cerebral impedance. In conclusion, these data strongly suggest active regulation of cerebral metabolism during the initial response to severe hypoxia, which may help to protect the immature brain from injury.

Parasomnias

2018 ◽  
Author(s):  
KyoungBin Im
Keyword(s):  
Mental Disorders ◽  
Rem Sleep ◽  
Slow Wave Sleep ◽  
Rem Sleep Behavior Disorder ◽  
Behavior Disorder ◽  
Nrem Sleep ◽  
Normal Subjects ◽  
Related Phenomenon ◽  
Sleep Behavior ◽  
Diagnostic And Statistical Manual

Parasomnias have long been recognized as part of sleep-related disorders or diseases in the mental disorders classification system such as Diagnostic and Statistical Manual of Mental Disorders. Nevertheless, many parasomnia symptoms are considered as a transient deviation from the norm in otherwise normal subjects due to disrupted status of consciousness. Sleep states are classified as rapid eye movement (REM) sleep and non-REM (NREM) sleep; similarly, parasomnias are classified as NREM-related parasomnias and REM-related parasomnias. NREM-related parasomnias share common pathophysiology of arousal-related phenomenon out of slow-wave sleep. Although listed as REM parasomnia disorders, nightmares and sleep paralysis are still considered comorbid symptoms or signs of other sleep disorders or mental disorders. Only REM sleep behavior disorder (RBD) is considered a relatively homogenous disease entity among all parasomnia diagnoses. Although RBD is the most newly added disorder entity in parasomnias, it is the most rigorously studied parasomnia such as RBD is strongly and clearly associated with concomitant or future developing neurodegenerative disease. This review contains 1 figure, 4 tables, and 18 references. Key Words: confusional arousals, dream enactment, pseudo-RBD, REM sleep behavior disorder, sleep-related eating, sleep terror, sleepwalking

Dysthymic Disorder and Rheumatic Pain Modulation Disorder (Fibrositis Syndrome): A Comparison of Symptoms and Sleep Physiology

1986 ◽  
Vol 31 (7) ◽  
pp. 608-616 ◽  
Author(s):  
Madhulika A. Gupta ◽  
Harvey Moldofsky
Keyword(s):  
Rem Sleep ◽  
Sleep Onset ◽  
High Amplitude ◽  
Depressive Illness ◽  
Pain Modulation ◽  
Dysthymic Disorder ◽  
Systematic Evaluation ◽  
Onset Latency ◽  
Rheumatic Pain ◽  
Sleep Physiology

It has been suggested that “fibrositis” or rheumatic pain modulation disorder (RPMD) is a varient of depressive illness. Both disorders are associated with abnormalities in sleep physiology. Since the clinical features of RPMD do not meet all the criteria for a major depressive disorder, the symptoms and sleep phsyiology in subjects with dysthmic disorder (DSM III criteria) (N = 6), and RMPD (N = 6) were compared, in order to determine the similarity between the two groups. The sleep physiology in dysthymic disorder was first examined over three consecutive nights since a systematic evaluation of the sleep physiology in this group of disorders has not yet been reported. All dysthymic patients showed episodic bursts of high-amplitude (75–150 microvolts) theta (3–5 Hz) bursts in stage 2 sleep, and REM onset latency was abbreviated only on night 2. The theta bursts have not been previously reported, and may be an early marker of disorganization of non-REM sleep in the dysthymic subjects. The comparison of the two groups revealed that RPMD subjects reported more pre- and post-sleep pain (p < 0.01), lighter sleep (p < 0.01), and more physical ailments during sleep (p < 0.01), and had more alpha (7–11.5 Hz) in non-REM sleep (p < 0.01). The dysthymic subjects who reported deeper sleep (p < 0.01), had a greater sleep continuity disturbance with longer stage 2 onset latency (p < 0.05), fewer hours of sleep (p < 0.05), more wakefulness after sleep onset (p < 0.05), more awakenings per hour of sleep (p < 0.01) and more stage changes per hour of sleep (p < 0.01), and showed theta bursts in stage 2 (p < 0.01). The distinctive symptoms and sleep physiologies in the two groups suggest that the two disorders are not related.

Neostriatal administration of somatostatin: differential effect of small and large doses on behavior and motor control

1977 ◽  
Vol 55 (2) ◽  
pp. 234-242 ◽  
Author(s):  
M. Rezek ◽  
V. Havlicek ◽  
L. Leybin ◽  
C. Pinsky ◽  
E. A. Kroeger ◽  
...  
Keyword(s):  
Motor Control ◽  
Eye Movements ◽  
Slow Wave ◽  
Rem Sleep ◽  
Differential Effect ◽  
Slow Wave Sleep ◽  
Small Doses ◽  
Freely Moving ◽  
Behavioral Excitation ◽  
Higher Doses

The administration of small doses of somatostatin (SRIF) (0.01 and 0.1 μg) into the neostriatal complex of unrestrained, freely moving rats induced general behavioral excitation associated with a variety of stereotyped movements, tremors, and a reduction of rapid eye movements (REM) and deep slow wave sleep (SWS). In contrast, the higher doses of SRIF (1.0 and 10.0 μg) caused movements to be uncoordinated and frequently induced more severe difficulties in motor control such as contralateral hemiplegia-in-extension which restricted or completely prevented the expression of normal behavioral patterns. As a result, the animals appeared drowsy and inhibited. Analysis of the sleep-waking cycle revealed prolonged periods of a shallow SWS while REM sleep and deep SWS were markedly reduced; electroencephalogram recordings revealed periods of dissociation from behavior. The administration of endocrinologically inactive as well as the active analogues of SRIF failed to induce effects comparable with those observed after the administration of the same dose of the native hormone (10.0 μg).

Ventilatory responses to CO2 and lung inflation in tonic versus phasic REM sleep

1979 ◽  
Vol 47 (6) ◽  
pp. 1304-1310 ◽  
Author(s):  
C. E. Sullivan ◽  
E. Murphy ◽  
L. F. Kozar ◽  
E. A. Phillipson
Keyword(s):  
Eye Movements ◽  
Rem Sleep ◽  
Slow Wave Sleep ◽  
Minute Volume ◽  
Sleep State ◽  
Lung Inflation ◽  
Ventilatory Responses ◽  
Sustained Inflation ◽  
Per Se ◽  
Phasic Rem Sleep

Ventilatory responses to CO2 and to lung inflation were compared in four dogs during tonic and phasic segments of rapid-eye-movement (REM) sleep. Phasic REM sleep (P-REM) was identified by the presence of bursts of rapid eye movements, visible muscle twitchings, and frequent phasic discharges in the nuchal electromyogram. These features were absent during tonic REM sleep (T-REM). During P-REM the response of minute volume of ventilation (VI) to progressive hypercapnia (0.58 +/- 0.19 (l/min)/Torr, mean +/- SE) was significantly less than in slow-wave sleep (SWS) (1.40 +/- 0.14; P less than 0.05). In contrast, during T-REM the response (1.48 +/- 0.19) was similar to that in SWS. Similarly, during P-REM the duration of apnea (5.9 +/- 1.5 s) elicited by sustained inflation of the lungs with 1.0 liter of air, was significantly shorter than in SWS (25.8 +/- 0.8); in contrast, during T-REM the duration of apnea (17.8 +/- 3.6) was similar to that in SWS. The results indicate that previously described decreases in VI responses to CO2 and apneic responses to lung inflation during P-REM, compared to SWS, are related to the phasic phenomena of REM sleep, rather than to the REM sleep state per se.

Consciousness among delta waves: a paradox?

Brain ◽  
2021 ◽  
Author(s):  
Joel Frohlich ◽  
Daniel Toker ◽  
Martin M Monti
Keyword(s):  
Slow Wave Sleep ◽  
Spectral Power ◽  
Vegetative State ◽  
Mitochondrial Diseases ◽  
Epileptic Seizures ◽  
High Amplitude ◽  
Convincing Evidence ◽  
Delta Activity ◽  
Parallel Body ◽  
Delta Oscillations

Abstract A common observation in EEG research is that consciousness vanishes with the appearance of delta (1 – 4 Hz) waves, particularly when those waves are high amplitude. High amplitude delta oscillations are very frequently observed in states of diminished consciousness, including slow wave sleep, anaesthesia, generalised epileptic seizures, and disorders of consciousness such as coma and vegetative state. This strong correlation between loss of consciousness and high amplitude delta oscillations is thought to stem from the widespread cortical deactivation that occurs during the “down states” or troughs of these slow oscillations. Recently, however, many studies have reported the presence of prominent delta activity during conscious states, which casts doubt on the hypothesis that high amplitude delta oscillations are an indicator of unconsciousness. These studies include work in Angelman syndrome, epilepsy, behavioural responsiveness during propofol anaesthesia, postoperative delirium, and states of dissociation from the environment such as dreaming and powerful psychedelic states. The foregoing studies complement an older, yet largely unacknowledged, body of literature that has documented awake, conscious patients with high amplitude delta oscillations in clinical reports from Rett syndrome, Lennox-Gastaut syndrome, schizophrenia, mitochondrial diseases, hepatic encephalopathy, and nonconvulsive status epilepticus. At the same time, a largely parallel body of recent work has reported convincing evidence that the complexity or entropy of EEG and magnetoencephalogram or MEG signals strongly relates to an individual’s level of consciousness. Having reviewed this literature, we discuss plausible mechanisms that would resolve the seeming contradiction between high amplitude delta oscillations and consciousness. We also consider implications concerning theories of consciousness, such as integrated information theory and the entropic brain hypothesis. Finally, we conclude that false inferences of unconscious states can be best avoided by examining measures of electrophysiological complexity in addition to spectral power.

scholarly journals Cerebral metabolic rate of oxygen during transition from wakefulness to sleep measured with high temporal resolution OxFlow MRI with concurrent EEG

2020 ◽  
pp. 0271678X2091928
Author(s):  
Alessandra Caporale ◽  
Hyunyeol Lee ◽  
Hui Lei ◽  
Hengyi Rao ◽  
Michael C Langham ◽  
...  
Keyword(s):  
Metabolic Rate ◽  
Slow Wave ◽  
Slow Wave Sleep ◽  
Cerebral Metabolism ◽  
Sleep Onset ◽  
High Temporal Resolution ◽  
Mean Values ◽  
Cerebral Metabolic Rate ◽  
Sleep Physiology ◽  
Concomitant Reduction

During slow-wave sleep, synaptic transmissions are reduced with a concomitant reduction in brain energy consumption. We used 3 Tesla MRI to noninvasively quantify changes in the cerebral metabolic rate of O2 (CMRO2) during wakefulness and sleep, leveraging the ‘OxFlow’ method, which provides venous O2 saturation (SvO2) along with cerebral blood flow (CBF). Twelve healthy subjects (31.3 ± 5.6 years, eight males) underwent 45–60 min of continuous scanning during wakefulness and sleep, yielding one image set every 3.4 s. Concurrent electroencephalography (EEG) data were available in eight subjects. Mean values of the metabolic parameters measured during wakefulness were stable, with coefficients of variation below 7% (average values: CMRO2 = 118 ± 12 µmol O2/min/100 g, SvO2 = 67.0 ± 3.7% HbO2, CBF = 50.6 ±4.3 ml/min/100 g). During sleep, on average, CMRO2 decreased 21% (range: 14%–32%; average nadir = 98 ± 16 µmol O2/min/100 g), while EEG slow-wave activity, expressed in terms of [Formula: see text]-power, increased commensurately. Following sleep onset, CMRO2 was found to correlate negatively with relative [Formula: see text]-power (r = −0.6 to −0.8, P < 0.005), and positively with heart rate (r = 0.5 to 0.8, P < 0.0005). The data demonstrate that OxFlow MRI can noninvasively measure dynamic changes in cerebral metabolism associated with sleep, which should open new opportunities to study sleep physiology in health and disease.

scholarly journals Insights into paradoxical (REM) sleep homeostatic regulation in mice using an innovative automated sleep deprivation method

SLEEP ◽  
2020 ◽  
Vol 43 (7) ◽  
Author(s):  
Sébastien Arthaud ◽  
Paul-Antoine Libourel ◽  
Pierre-Hervé Luppi ◽  
Christelle Peyron
Keyword(s):  
Slow Wave ◽  
Rem Sleep ◽  
High Efficiency ◽  
Environmental Changes ◽  
Slow Wave Sleep ◽  
Paradoxical Sleep ◽  
Corticosterone Level ◽  
Plasma Corticosterone ◽  
Homeostatic Regulation ◽  
External Modulation

Abstract Identifying the precise neuronal networks activated during paradoxical sleep (PS, also called REM sleep) has been a challenge since its discovery. Similarly, our understanding of the homeostatic mechanisms regulating PS, whether through external modulation by circadian and ultradian drives or via intrinsic homeostatic regulation, is still limited, largely due to interfering factors rendering the investigation difficult. Indeed, none of the studies published so far were able to manipulate PS without significantly altering slow-wave sleep and/or stress level, thus introducing a potential bias in the analyses. With the aim of achieving a better understanding of PS homeostasis, we developed a new method based on automated scoring of vigilance states—using electroencephalogram and electromyogram features—and which involves closed-loop PS deprivation through the induction of cage floor movements when PS is detected. Vigilance states were analyzed during 6 and 48 h of PS deprivation as well as their following recovery periods. Using this new automated methodology, we were able to deprive mice of PS with high efficiency and specificity, for short or longer periods of time, observing no sign of stress (as evaluated by plasma corticosterone level and sleep latency) and requiring no human intervention or environmental changes. We show here that PS can be homeostatically modulated and regulated while no significant changes are induced on slow-wave sleep and wakefulness, with a PS rebound duration depending on the amount of prior PS deficit. We also show that PS interval duration is not correlated with prior PS episode duration in the context of recovery from PS deprivation.

Each distinct type of mental state is supported by specific brain functions

2000 ◽  
Vol 23 (6) ◽  
pp. 941-943 ◽  
Author(s):  
Claude Gottesmann
Keyword(s):  
Slow Wave ◽  
Mental State ◽  
Rem Sleep ◽  
Psychological Functioning ◽  
Slow Wave Sleep ◽  
Mental Content ◽  
Distinct Type ◽  
Inhibitory Processes ◽  
Brain Functions

Reflective waking mentation is supported by cortical activating and inhibitory processes. The thought-like mental content of slow wave sleep appears with lower levels of both kinds of influence. During REM sleep, the equation: activation + disinhibition + dopamine may explain the often psychotic-like mode of psychological functioning.[Hobson et al.; Nielsen; Revonsuo; Solms; Vertes & Eastman]

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