scholarly journals Dynamic modulation of theta–gamma coupling during rapid eye movement sleep

SLEEP ◽  
2019 ◽  
Vol 42 (12) ◽  
Author(s):  
Mojtaba Bandarabadi ◽  
Richard Boyce ◽  
Carolina Gutierrez Herrera ◽  
Claudio L Bassetti ◽  
Sylvain Williams ◽  
...  
Keyword(s):  
Eye Movement ◽  
Rem Sleep ◽  
Temporal Dynamics ◽  
Brain Structures ◽  
Rapid Eye Movement ◽  
Sleep Episode ◽  
Frequency Coupling ◽  
Theta Phase ◽  
Hippocampal Networks ◽  
Cross Frequency Coupling

Abstract Theta phase modulates gamma amplitude in hippocampal networks during spatial navigation and rapid eye movement (REM) sleep. This cross-frequency coupling has been linked to working memory and spatial memory consolidation; however, its spatial and temporal dynamics remains unclear. Here, we first investigate the dynamics of theta–gamma interactions using multiple frequency and temporal scales in simultaneous recordings from hippocampal CA3, CA1, subiculum, and parietal cortex in freely moving mice. We found that theta phase dynamically modulates distinct gamma bands during REM sleep. Interestingly, we further show that theta–gamma coupling switches between recorded brain structures during REM sleep and progressively increases over a single REM sleep episode. Finally, we show that optogenetic silencing of septohippocampal GABAergic projections significantly impedes both theta–gamma coupling and theta phase coherence. Collectively, our study shows that phase-space (i.e. cross-frequency coupling) coding of information during REM sleep is orchestrated across time and space consistent with region-specific processing of information during REM sleep including learning and memory.

scholarly journals An Asymmetrical Hypothesis for the NREM-REM Sleep Alternation—What Is the NREM-REM Cycle?

2021 ◽  
Vol 15 ◽  
Author(s):  
Olivier Le Bon
Keyword(s):  
Eye Movement ◽  
Rem Sleep ◽  
Refractory Period ◽  
High Variability ◽  
Oscillator Model ◽  
Rapid Eye Movement ◽  
Sleep Regulation ◽  
Short Term ◽  
Sleep Episode ◽  
Sleep Homeostasis

Since the discovery of rapid eye movement (REM) sleep (Aserinsky and Kleitman, 1953), sleep has been described as a succession of cycles of non-REM (NREM) and REM sleep episodes. The hypothesis of short-term REM sleep homeostasis, which is currently the basis of most credible theories on sleep regulation, is built upon a positive correlation between the duration of a REM sleep episode and the duration of the interval until the next REM sleep episode (inter-REM interval): the duration of REM sleep would therefore predict the duration of this interval. However, the high variability of inter-REM intervals, especially in polyphasic sleep, argues against a simple oscillator model. A new “asymmetrical” hypothesis is presented here, where REM sleep episodes only determine the duration of a proportional post-REM refractory period (PRRP), during which REM sleep is forbidden and the only remaining options are isolated NREM episodes or waking. After the PRRP, all three options are available again (NREM, REM, and Wake). I will explain why I think this hypothesis also calls into question the notion of NREM-REM sleep cycles.

scholarly journals Changes in cross-frequency coupling following closed-loop auditory stimulation in non-rapid eye movement sleep

2019 ◽  
Author(s):  
Krugliakova Elena ◽  
Volk Carina ◽  
Jaramillo Valeria ◽  
Sousouri Georgia ◽  
Huber Reto
Keyword(s):  
Eye Movement ◽  
Closed Loop ◽  
Auditory Stimulation ◽  
Brain Network ◽  
Slow Waves ◽  
Dependent Manner ◽  
Rapid Eye Movement ◽  
Frequency Coupling ◽  
The Right ◽  
Cross Frequency Coupling

AbstractThe activity of different brain networks in non-rapid eye movement (NREM) sleep is regulated locally in an experience-dependent manner, reflecting the extent of the network load during wakefulness. In particular, improved task performance after sleep correlates with the local post-learning power increase of neocortical slow waves and faster oscillations such as sleep spindles and their temporal coupling. Recently, it was demonstrated that by targeting slow waves in a particular region at a particular phase with closed-loop auditory stimulation it is possible to locally manipulate slow-wave activity and interact with training-induced neuroplastic changes. Based on this finding, we tested whether closed-loop auditory stimulation targeting the up-phase of slow-waves over the right sensorimotor area might affect power in delta, theta and sigma bands and coupling between these oscillations within the circumscribed region. We demonstrate that while closed-loop auditory stimulation globally enhances power in delta, theta and sigma bands, changes in cross-frequency coupling of these oscillations were more spatially restricted. In particular, stimulation induced a significant decrease of delta-theta coupling in frontal channels, within the area of the strongest baseline coupling between these frequency bands. In contrast, a significant increase in delta-sigma coupling was observed over the right parietal area, located directly posterior to the target electrode. These findings suggest that closed-loop auditory stimulation locally modulates coupling between delta phase and sigma power in a targeted region, which could be used to manipulate sleep-dependent memory formation within the brain network of interest.

scholarly journals Neurophysiological control of sleep with special emphasis on melatonin

2020 ◽  
Vol 18 (4) ◽  
pp. 355-376
Author(s):  
Iv. Penchev Georgiev
Keyword(s):  
Sleep Disorders ◽  
Eye Movement ◽  
Rem Sleep ◽  
Sleep Onset ◽  
Vascular Diseases ◽  
Nrem Sleep ◽  
Brain Structures ◽  
Rapid Eye Movement ◽  
Human Beings ◽  
Melatonin Receptor Agonists

Sleep and wakefulness are two main types of human and animal behavior. On the average human beings spend about one-third of their lives asleep. The sleep-wake cycle is the most important circadian rhythms which alternates in a periodic manner lasting for about 24 hours. Sleep is determined as the natural periodic suspension of consciousness characterized by relative immobility and reduced responsiveness to external stimuli. The researchers have found and identified many special brain structures and systems controlling waking, rapid eye movement (REM) sleep and non-rapid eye (NREM) sleep and the transitions among these states. Currently, there is an enhanced interest of researchers toward sleep and its neurophysiological mechanisms of regulation because the number of people suffering from various sleep disturbance such as insomnia, delayed sleep onset, duration and propensity of sleep, worldwide dramatically increases. In addition to the next day drowsiness, nervousness, tiredness and decreased workability, it has been suggested that sleep is important also for the maintaining of mood, memory and cognitive function of the brain and is essential for the normal functioning of the endocrine and immune systems. More recently, new studies show a sustained link between sleep disorders and different serious health problems, including obesity, insulin resistance, type 2 diabetes mellitus, cardio-vascular diseases and depression. Therefore, the purpose of this review is to summarize and analyze the available data about the neurological control of wakefulness, non-rapid-eye-movement (NREM) sleep and rapid- eye-movement (REM) sleep creating a substantial basis for better understanding different sleep disorders. Special attention is paid on the pharmacological aspects and use of some new classes of sleep promoting agents – melatonin, melatonin receptor agonists and orexin receptor antagonists.

scholarly journals The Relationship Between Daily Rapid-Eye Movement Sleep and Cognitive Functioning in Older Adults

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 159-159
Author(s):  
Tiana Broen ◽  
Tomiko Yoneda ◽  
Jonathan Rush ◽  
Jamie Knight ◽  
Nathan Lewis ◽  
...  
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Cognitive Functioning ◽  
Eye Movement ◽  
Rem Sleep ◽  
Cognitive Tests ◽  
Rapid Eye Movement ◽  
Targeted Interventions ◽  
The Impact ◽  
The Relationship

Abstract Previous cross-sectional research suggests that age-related decreases in Rapid-Eye Movement (REM) sleep may contribute to poorer cognitive functioning (CF); however, few studies have examined the relationship at the intraindividual level by measuring habitual sleep over multiple days. Applying a 14-day daily diary design, the current study examines the dynamic relationship between REM sleep and CF in 69 healthy older adults (M age=70.8 years, SD=3.37; 73.9% female; 66.6% completed at least an undergraduate degree). A Fitbit device provided actigraphy indices of REM sleep (minutes and percentage of total sleep time), while CF was measured four times daily on a smartphone via ambulatory cognitive tests that captured processing speed and working memory. This research addressed the following questions: At the within-person level, are fluctuations in quantity of REM sleep associated with fluctuations in next day cognitive measures across days? Do individuals who spend more time in REM sleep on average, perform better on cognitive tests than adults who spend less time in REM sleep? A series of multilevel models were fit to examine the extent to which each index of sleep accounted for daily fluctuations in performance on next day cognitive tests. Results indicated that during nights when individuals had more REM sleep minutes than was typical, they performed better on the working memory task the next morning (estimate = -.003, SE = .002, p = .02). These results highlight the impact of REM sleep on CF, and further research may allow for targeted interventions for earlier treatment of sleep-related cognitive impairment.

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