scholarly journals Altered sleep spindles and slow waves during space shuttle missions

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Dominik P. Koller ◽  
Vida Kasanin ◽  
Erin E. Flynn-Evans ◽  
Jason P. Sullivan ◽  
Derk-Jan Dijk ◽  
...  
Keyword(s):  
Sleep Quality ◽  
Slow Wave ◽  
Wave Amplitude ◽  
Space Shuttle ◽  
Slow Waves ◽  
Sleep Spindles

AbstractSleep deficiencies and associated performance decrements are common among astronauts during spaceflight missions. Previously, sleep in space was analyzed with a focus on global measures while the intricate structure of sleep oscillations remains largely unexplored. This study extends previous findings by analyzing how spaceflight affects characteristics of sleep spindles and slow waves, two sleep oscillations associated with sleep quality and quantity, in four astronauts before, during and after two Space Shuttle missions. Analysis of these oscillations revealed significantly increased fast spindle density, elevated slow spindle frequency, and decreased slow wave amplitude in space compared to on Earth. These results reflect sleep characteristics during spaceflight on a finer electrophysiological scale and provide an opportunity for further research on sleep in space.

scholarly journals 0061 Does Combining M1 M2 Reference Influence Amplitude of Slow Waves?

SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A24-A24
Author(s):  
N A Walker ◽  
H L Roth ◽  
Z Fan ◽  
B V Vaughn
Keyword(s):  
Slow Wave ◽  
Wave Amplitude ◽  
Wave Activity ◽  
Slow Waves ◽  
Measurement Tool ◽  
Average Difference ◽  
Average Standard Deviation ◽  
Electrode Distance ◽  
Amplitude Measurement ◽  
Average Loss

Abstract Introduction Slow wave amplitudes are critical to determining Stage N3 sleep yet ECG artifact frequently interferes with accurate amplitude measurement. This artifact may be lessened by using a combined M1-M2 reference however theoretically this may decrease the amplitude due to shorter inter-electrode distance (predicted 27% loss). The AASM Scoring Manual recommends scoring slow wave activity using F4-M1 channel or alternatively F3-M2, but does not recognize a combined reference. This study measures the differences in slow wave amplitude using contralateral versus combine reference. Methods 12 polysomnograms were randomly selected for analysis of amplitude of slow wave using contralateral and combined reference channels. Six separate EEG channels (F3-M1, F3-M2, F3-M1+M2, F4-M1, F4-M2, and F4-M1+M2) were used to analyze 25 different slow waves from each polysomnogram. Individual slow waves from Stage N3 sleep were analyzed using the Natus Sleepworks Amplitude Measurement Tool if their peak and trough were free EKG artifact. Averages and standard deviations of the waveforms were calculated for each patient and channel. Differences were normalized by dividing by the amplitude of the original wave using the contralateral reference. Results Subjects age ranged from 30–69 yrs, with 6 being females. Mean amplitudes were as follows: F3-M2 was 131.75µV, F3-M1+M2 125.84 µV, F4-M1 130.57 µV, and F4-M1+M2 128.22µV. The overall average difference of F4-M1 to F4-M1+M2 was 0.92% and the average difference of F3-M2 to F3-M1+M2 was 3.52% with the average standard deviation of 8.47%. Conclusion This study shows the average loss in amplitude of converting F4-M1 to F4-M1+M2 was less than 1% and 3.5% for F3-M2 to F3-M1+M2. Combining M1M2 reference may be a valuable alternative to reduce EKG artifact. Support None

scholarly journals The effect of cholecystokinin peptides on ovine duodeno-jejunal slow waves with and without pretreatment with proglumide

2007 ◽  
Vol 78 (4) ◽  
Author(s):  
K.W. Romanski
Keyword(s):  
Slow Wave ◽  
Wave Amplitude ◽  
Phase 1 ◽  
Late Phase ◽  
Duodenal Bulb ◽  
Slow Waves ◽  
High Dose ◽  
Myoelectric Activity ◽  
Intestinal Slow Waves ◽  
Cck Receptor Antagonist

Cholecystokinin exerts a composite influence on gastrointestinal motility but little is known about its effect on small-intestinal slow waves. Thus, six rams were implanted with four bipolar serosal electrodes onto the duodeno-jejunal wall. In the course of chronic experiments the myoelectric activity was continuously recorded in the non-fasted animals. After recording of the full normal migrating myoelectric complex (MMC), 0.15 M NaCl or CCK peptides were injected intravenously during various phases of the next MMC cycle. Five mℓ of saline was injected over 30 s during phases 1, 2a, or 2b of the MMC. Cerulein was administered at doses of 1 (over 30 s), 10 (over 30 or 60 s), or 100 ng/kg (over 30, 60, 120 or 300 s) and cholecystokinin octapeptide (CCK-OP) at doses 20 times higher. CCK peptides were applied during early or late phase 1 of the MMC and during phases 2a and 2b of the MMC. In the course of additional experiments, saline and hormone administration was directly preceded by infusion of proglumide, an unspecific CCK receptor antagonist, at a dose of 10 mg/kg. The myoelectric recordings were continued until the arrival of a subsequent regular phase 3 of theMMC.In the duodenal bulb, slow waves were occasionally observed. In the duodenum the slow-wave frequency oscillated between 20 and 24 cpm and in the jejunum between 19 and 22 cpm before or after CCK peptides and proglumide. In the duodenum the slow-wave amplitude increased significantly after all doses of cerulein injected during phase 2b of the MMC. After administration of CCK-OP changes in duodenal slow-wave amplitude were not significant but exhibited a tendency similar to those after cerulein. In the jejunum, injection of cerulein and CCK-OP during phase 2 of the MMC increased the slow-wave amplitude significantly and the duration of these changes was longer than in the duodenum. After infusion of proglumide, administration of cerulein at the low dose over 30 s and at the high dose over 300 s in the course of late phase 1 and phases 2a and 2b of the MMC, significantly increased the duodenal slow-wave amplitude. Cerulein injection during phase 2b of the MMC at the high dose over 30 and 60 s, preceded by proglumide infusion, significantly inhibited the duodenal slow-wave amplitude. In the jejunum these changes were even more pronounced and their duration was much longer. It is concluded that CCK peptides affect slow-wave amplitude in the duodeno-jejunum in non-fasted sheep. This effect is stronger in the jejunum and is altered but not abolished by pretreatment with proglumide. Cerulein evokes more pronounced alterations in the slow-wave amplitude than CCK-OP in conscious sheep.

Excitation-contraction coupling without Ca2+ action potentials in small intestine

1983 ◽  
Vol 244 (5) ◽  
pp. C356-C361 ◽  
Author(s):  
K. M. Sanders
Keyword(s):  
Small Intestine ◽  
Slow Wave ◽  
Action Potentials ◽  
Wave Amplitude ◽  
Channel Blocker ◽  
Slow Waves ◽  
Contractile Apparatus ◽  
Contraction Coupling ◽  
Wave Cycle ◽  
The Relationship

Sensitive mechanical and intracellular electrical recordings showed that phasic contractions occurred in response to electrical slow waves in the absence of Ca2+ action potentials. Drugs that either enhanced or depressed slow waves were used to study the relationship between slow-wave amplitude and the amplitude of the phasic contractions. Acetylcholine (Ach) (10(-8) to 3 X 10(-7) M) increased slow waves and contractions without causing action potentials. When ACh was raised to 10(-6) M, action potentials were elicited and accompanying contractions increased in amplitude by at least a factor of five. The Ca2+ channel blocker, Mn2+ (0.5 mM), decreased slow-wave amplitude and the associated phasic contractions. These data agree with a previous study (12), suggesting that an oscillation in intracellular Ca2+ occurs during each slow-wave cycle. The present study suggests that the increase in intracellular Ca2+ during the slow wave is sufficient to activate the contractile apparatus.

033 The effect of sleep disturbance on cognition in late-life depression

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A15-A15
Author(s):  
Andrea Ricciardiello ◽  
Sharon Naismith ◽  
Angela D’Rozario ◽  
Fiona Kumfor ◽  
Rick Wassing
Keyword(s):  
Executive Function ◽  
Sleep Disturbance ◽  
Slow Wave ◽  
Cognitive Deficits ◽  
Memory Performance ◽  
Verbal Learning ◽  
Late Life ◽  
Control Group ◽  
Sleep Spindles ◽  
Late Life Depression

Abstract Introduction Late-life depression is the most common psychiatric disorder in older adults and is associated with cognitive deficits, however, the role of sleep disturbance in cognitive deficits is poorly defined. In the current study we aimed to examine sleep macro and micro-architecture differences between those with late-life depression and controls. Secondly, we sought to determine how sleep changes relate to clinical memory and executive function measures in those with late-life depression and controls. Methods Using prior clinical data, this retrospective study assessed adults >50 years who had completed an overnight PSG study and comprehensive psychiatric, neuropsychological, and medical assessment. Memory performance was measured using the Weschler Memory Scale logical Memory 1 and 2 components, Rey Auditory Verbal Learning Test (Senior) 30-minute recall and Rey Complex Figure 3-minute recall. Executive function was defined by z scores from Trail Making Test, D-KEFS Stroop Test and Controlled Oral Word Association Test. The sample comprised of 71 depressed participants, defined by a Geriatric Depression Scale score ≥6, and 101 non-depressed participants (GDS <6 and no lifetime history of depression using DSM-IV criteria). Results Contrary to our hypothesis no significant macroarchitectural differences were observed between the groups. Less time spent in slow-wave sleep (SWS) was associated with worse delayed memory recall scores in the depression group (z=.342, p=0.008) although this was not seen in the control group. SWS and slow wave activity (SWA) were not related to measures of executive function performance. Depressed participants demonstrated a reduced level of sleep spindles (Dep= 159 ±142.8, con= 213±163, p=.03) although there were no associations with memory outcomes. Conclusion Compared to younger adults with depression, macroarchitectural differences in those with late-life depression are not as pronounced, due to a reduction of SWS and SWA power as a function of ageing. The efficiency of SWS hippocampal dependent memory processes in depression may be reduced, therefore, more time spent in SWS is related to better memory performance. This study assessed the density of sleep spindles but not spindle and slow wave oscillation coupling which may be more important for hippocampal dependent memory. Support (if any):

scholarly journals The Aging Slow Wave: A Shifting Amalgam of Distinct Slow Wave and Spindle Coupling Subtypes Define Slow Wave Sleep Across the Human Lifespan

SLEEP ◽  
2021 ◽  
Author(s):  
Brice V McConnell ◽  
Eugene Kronberg ◽  
Peter D Teale ◽  
Stefan H Sillau ◽  
Grace M Fishback ◽  
...  
Keyword(s):  
Slow Wave ◽  
Neurological Disease ◽  
Mixed Model ◽  
Slow Wave Sleep ◽  
Sleep Stage ◽  
Slow Waves ◽  
Cross Sectional ◽  
Relative Contribution ◽  
Human Lifespan ◽  
Development And Aging

Abstract Study Objectives Slow wave and spindle coupling supports memory consolidation, and loss of coupling is linked with cognitive decline and neurodegeneration. Coupling is proposed to be a possible biomarker of neurological disease, yet little is known about the different subtypes of coupling that normally occur throughout human development and aging. Here we identify distinct subtypes of spindles within slow wave upstates and describe their relationships with sleep stage across the human lifespan. Methods Coupling within a cross-sectional cohort of 582 subjects was quantified from stages N2 and N3 sleep across ages 6-88 years old. Results were analyzed across the study population via mixed model regression. Within a subset of subjects, we further utilized coupling to identify discrete subtypes of slow waves by their coupled spindles. Results Two different subtypes of spindles were identified during the upstates of (distinct) slow waves: an “early-fast” spindle, more common in stage N2 sleep, and a “late-fast” spindle, more common in stage N3. We further found stages N2 and N3 sleep contain a mixture of discrete subtypes of slow waves, each identified by their unique coupled-spindle timing and frequency. The relative contribution of coupling subtypes shifts across the human lifespan, and a deeper sleep phenotype prevails with increasing age. Conclusions Distinct subtypes of slow waves and coupled spindles form the composite of slow wave sleep. Our findings support a model of sleep-dependent synaptic regulation via discrete slow wave/spindle coupling subtypes and advance a conceptual framework for the development of coupling-based biomarkers in age-associated neurological disease.

scholarly journals A pilot study on essential oil aroma stimulation for enhancing slow-wave EEG in sleeping brain

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Li-Wei Ko ◽  
Cheng-Hua Su ◽  
Meng-Hsun Yang ◽  
Shen-Yi Liu ◽  
Tung-Ping Su
Keyword(s):  
Essential Oil ◽  
Sleep Quality ◽  
Slow Wave ◽  
Slow Wave Sleep ◽  
Sleep Eeg ◽  
Poor Sleep ◽  
Alpha Power ◽  
Poor Sleep Quality ◽  
Healthy Human ◽  
Study Results

AbstractSleep quality is important to health and life quality. Lack of sleep can lead to a variety of health issues and reduce in daytime function. Recent study by Fultz et al. also indicated that sleep is crucial to brain metabolism. Delta power in sleep EEG often indicates good sleep quality while alpha power usually indicates sleep interruptions and poor sleep quality. Essential oil has been speculated to improve sleep quality. Previous studies also suggest essential oil aroma may affect human brain activity when applied awake. However, those studies were often not blinded, which makes the effectiveness and mechanism of aroma a heavily debated topic. In this study, we aim to explore the effect of essential oil aroma on human sleep quality and sleep EEG in a single-blinded setup. The aroma was released when the participants are asleep, which kept the influence of psychological expectation to the minimum. We recruited nine young, healthy participants with regular lifestyle and no sleep problem. All participants reported better sleep quality and more daytime vigorous after exposing to lavender aroma in sleep. We also observed that upon lavender aroma releases, alpha wave in wake stage was reduced while delta wave in slow-wave sleep (SWS) was increased. Lastly, we found that lavender oil promote occurrence of SWS. Overall, our study results show that essential oil aroma can be used to promote both subjective and objective sleep quality in healthy human subjects. This makes aroma intervention a potential solution for poor sleep quality and insomnia.

scholarly journals Abnormal gastric slow waves in patients with functional dyspepsia assessed by multichannel electrogastrography

2001 ◽  
Vol 280 (6) ◽  
pp. G1370-G1375 ◽  
Author(s):  
Xuemei Lin ◽  
Jiande Z. Chen
Keyword(s):  
Wave Propagation ◽  
Functional Dyspepsia ◽  
Slow Wave ◽  
Single Channel ◽  
Slow Waves ◽  
Lower Percentage ◽  
Healthy Controls ◽  
Fasting State ◽  
Gastric Slow Wave ◽  
Gastric Slow Waves

The aim of this study was to utilize multichannel electrogastrography to investigate whether patients with functional dyspepsia had impaired propagation or coordination of gastric slow waves in the fasting state compared with healthy controls. The study was performed in 10 patients with functional dyspepsia and 11 healthy subjects. Gastric myoelectrical activity was measured by using surface electrogastrography with a specially designed four-channel device. The study was performed for 30 min or more in the fasting state. Special computer programs were developed for the computation of the propagation and coupling of the gastric slow wave. It was found that, compared with the healthy controls, the patients showed a significantly lower percentage of slow wave propagation (58.0 ± 8.9 vs. 89.9 ± 2.6%, P < 0.002) and a significantly lower percentage of slow wave coupling (46.9 ± 4.4 vs. 61.5 ± 6.9%, P < 0.04). In addition, the patients showed inconsistencies in the frequency and regularity of the gastric slow wave among the four-channel electrogastrograms (EGGs). It was concluded that patients with functional dyspepsia have impaired slow wave propagation and coupling. Multichannel EGG has more information than single-channel EGG for the detection of gastric myoelectrical abnormalities.

scholarly journals 0093 Dynamics Of Cortical Sleep Spindles And Slow Waves Following Motor Learning In Mice

SLEEP ◽  
2018 ◽  
Vol 41 (suppl_1) ◽  
pp. A37-A38
Author(s):  
K Kam ◽  
W Pettibone ◽  
A Varga
Keyword(s):  
Motor Learning ◽  
Slow Waves ◽  
Sleep Spindles

scholarly journals Selection of stimulus parameters for enhancing slow wave sleep events with a Neural-field theory thalamocortical computational model

2021 ◽  
Author(s):  
Felipe A. Torres ◽  
Patricio Orio ◽  
María-José Escobar
Keyword(s):  
Computational Model ◽  
Slow Wave ◽  
Memory Consolidation ◽  
Closed Loop ◽  
Slow Wave Sleep ◽  
Brain Activity ◽  
Sensory Stimulation ◽  
Sleep Spindles ◽  
Slow Oscillations ◽  
Closed Loop Stimulation

AbstractSlow-wave sleep cortical brain activity, conformed by slow-oscillations and sleep spindles, plays a key role in memory consolidation. The increase of the power of the slow-wave events, obtained by auditory sensory stimulation, positively correlates to memory consolidation performance. However, little is known about the experimental protocol maximizing this effect, which could be induced by the power of slow-oscillation, the number of sleep spindles, or the timing of both events’ co-occurrence. Using a mean-field model of thalamocortical activity, we studied the effect of several stimulation protocols, varying the pulse shape, duration, amplitude, and frequency, as well as a target-phase using a closed-loop approach. We evaluated the effect of these parameters on slow-oscillations (SO) and sleep-spindles (SP), considering: (i) the power at the frequency bands of interest, (ii) the number of SO and SP, (iii) co-occurrences between SO and SP, and (iv) synchronization of SP with the up-peak of the SO. The first three targets are maximized using a decreasing ramp pulse with a pulse duration of 50 ms. Also, we observed a reduction in the number of SO when increasing the stimulus energy by rising its amplitude. To assess the target-phase parameter, we applied closed-loop stimulation at 0º, 45º, and 90º of the phase of the narrow-band filtered ongoing activity, at 0.85 Hz as central frequency. The 0º stimulation produces better results in the power and number of SO and SP than the rhythmic or aleatory stimulation. On the other hand, stimulating at 45º or 90º change the timing distribution of spindles centers but with fewer co-occurrences than rhythmic and 0º phase. Finally, we propose the application of closed-loop stimulation at the rising zero-cross point using pulses with a decreasing ramp shape and 50 ms of duration for future experimental work.Author summaryDuring the non-REM (NREM) phase of sleep, events that are known as slow oscillations (SO) and spindles (SP) can be detected by EEG. These events have been associated with the consolidation of declarative memories and learning. Thus, there is an ongoing interest in promoting them during sleep by non-invasive manipulations such as sensory stimulation. In this paper, we used a computational model of brain activity that generates SO and SP, to investigate which type of sensory stimulus –shape, amplitude, duration, periodicity– would be optimal for increasing the events’ frequency and their co-occurrence. We found that a decreasing ramp of 50 ms duration is the most effective. The effectiveness increases when the stimulus pulse is delivered in a closed-loop configuration triggering the pulse at a target phase of the ongoing SO activity. A desirable secondary effect is to promote SPs at the rising phase of the SO oscillation.

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