scholarly journals The Defensive Activation Theory: REM Sleep as a Mechanism to Prevent Takeover of the Visual Cortex

2021 ◽  
Vol 15 ◽  
Author(s):  
David M. Eagleman ◽  
Don A. Vaughn
Keyword(s):  
Visual Cortex ◽  
Eye Movement ◽  
Rem Sleep ◽  
Rapid Eye Movement ◽  
Activation Theory ◽  
Continuous Activity ◽  
The Brain ◽  
New Hypothesis

Regions of the brain maintain their territory with continuous activity: if activity slows or stops (e.g., because of blindness), the territory tends to be taken over by its neighbors. A surprise in recent years has been the speed of takeover, which is measurable within an hour. These findings lead us to a new hypothesis on the origin of REM sleep. We hypothesize that the circuitry underlying REM sleep serves to amplify the visual system’s activity periodically throughout the night, allowing it to defend its territory against takeover from other senses. We find that measures of plasticity across 25 species of primates correlate positively with the proportion of rapid eye movement (REM) sleep. We further find that plasticity and REM sleep increase in lockstep with evolutionary recency to humans. Finally, our hypothesis is consistent with the decrease in REM sleep and parallel decrease in neuroplasticity with aging.

scholarly journals The Defensive Activation theory: dreaming as a mechanism to prevent takeover of the visual cortex

2020 ◽  
Author(s):  
David M. Eagleman ◽  
Don A. Vaughn
Keyword(s):  
Visual Cortex ◽  
Eye Movement ◽  
Rem Sleep ◽  
Rapid Eye Movement ◽  
Activation Theory ◽  
Continuous Activity ◽  
The Brain ◽  
New Hypothesis

AbstractRegions of the brain maintain their territory with continuous activity: if activity slows or stops (e.g., because of blindness), the territory tends to be taken over by its neighbors. A surprise in recent years has been the speed of takeover, which is measurable within an hour. These findings lead us to a new hypothesis on the origin of dream sleep. We hypothesize that the circuitry underlying dreaming serves to amplify the visual system’s activity periodically throughout the night, allowing it to defend its territory against takeover from other senses. We find that measures of plasticity across 25 species of primates correlate positively with the proportion of rapid eye movement (REM) sleep. We further find that plasticity and REM sleep increase in lockstep with evolutionary recency to humans. Finally, our hypothesis is consistent with the decrease in REM sleep and parallel decrease in neuroplasticity with aging.

Sleep Disorders

2016 ◽  
pp. 275-296
Author(s):  
Douglas J. Gelb
Keyword(s):  
Sleep Disorders ◽  
Eye Movement ◽  
Rem Sleep ◽  
Nrem Sleep ◽  
The Body ◽  
Rapid Eye Movement ◽  
Cyclic Activity ◽  
Abnormal Behaviors ◽  
The Brain ◽  
Meaningful Stimuli

Sleep consists of a highly patterned sequence of cyclic activity in various regions of the brain; it is not simply a state of temporary unconsciousness. Although the brain is less responsive than normal during sleep, it is not totally unresponsive. In fact, during sleep the brain responds more readily to meaningful stimuli. Rapid eye movement (REM) sleep can be characterized as a period when the brain is active and the body is paralyzed, whereas in nonrapid eye movement (NREM) sleep, the brain is less active but the body can move. Sleep disorders are grouped into three general categories, based on whether patients have trouble staying awake, trouble sleeping, or abnormal behaviors during sleep.

scholarly journals Cortical monitoring of cardiac activity during rapid eye movement sleep: the heartbeat evoked potential in phasic and tonic REM microstates

SLEEP ◽  
2021 ◽  
Author(s):  
Péter Simor ◽  
Tamás Bogdány ◽  
Róbert Bódizs ◽  
Pandelis Perakakis
Keyword(s):  
Eye Movement ◽  
Sensory Processing ◽  
Rem Sleep ◽  
Evoked Potential ◽  
Physiological State ◽  
Cardiac Activity ◽  
Nrem Sleep ◽  
Rapid Eye Movement ◽  
Heartbeat Evoked Potential ◽  
The Brain

Abstract Sleep is a fundamental physiological state that facilitates neural recovery during periods of attenuated sensory processing. On the other hand, mammalian sleep is also characterized by the interplay between periods of increased sleep depth and environmental alertness. Whereas the heterogeneity of microstates during non-rapid-eye-movement (NREM) sleep was extensively studied in the last decades, transient microstates during REM sleep received less attention. REM sleep features two distinct microstates: phasic and tonic. Previous studies indicate that sensory processing is largely diminished during phasic REM periods, whereas environmental alertness is partially reinstated when the brain switches into tonic REM sleep. Here, we investigated interoceptive processing as quantified by the heartbeat evoked potential (HEP) during REM microstates. We contrasted the HEPs of phasic and tonic REM periods using two separate databases that included the nighttime polysomnographic recordings of healthy young individuals (N = 20 and N = 19). We find a differential HEP modulation of a late HEP component (after 500 ms post-R-peak) between tonic and phasic REM. Moreover, the late tonic HEP component resembled the HEP found in resting wakefulness. Our results indicate that interoception with respect to cardiac signals is not uniform across REM microstates, and suggest that interoceptive processing is partially reinstated during tonic REM periods. The analyses of the HEP during REM sleep may shed new light on the organization and putative function of REM microstates.

Eye movements modulate interoceptive processing during rapid eye movement sleep: the heartbeat evoked potential in phasic and tonic REM microstates

2020 ◽  
Author(s):  
Péter Simor ◽  
Bogdány Tamás ◽  
Robert Bodizs ◽  
Pandelis Perakakis
Keyword(s):  
Eye Movement ◽  
Sensory Processing ◽  
Rem Sleep ◽  
Evoked Potential ◽  
Physiological State ◽  
Nrem Sleep ◽  
Rapid Eye Movement ◽  
Rapid Eye Movement Sleep ◽  
Heartbeat Evoked Potential ◽  
The Brain

Sleep is a fundamental physiological state that facilitates neural recovery during periods of attenuated sensory processing. On the other hand, mammalian sleep is also characterized by the interplay between periods of increased sleep depth and environmental alertness. Whereas the heterogeneity of microstates during non-rapid-eye-movement (NREM) sleep was extensively studied in the last decades, transient microstates during REM sleep received less attention. REM sleep features two distinct microstates: phasic and tonic. Previous studies indicate that sensory processing is largely diminished during phasic REM periods, whereas environmental alertness is partially reinstated when the brain switches into tonic REM sleep. Here, we investigated interoceptive processing as quantified by the heartbeat evoked potential (HEP) during REM microstates. We contrasted the HEPs of phasic and tonic REM periods using two separate databases that included the nighttime polysomnographic recordings of healthy young individuals (N = 20 and N = 19). We find a differential HEP modulation of a late HEP component (after 500 ms post-R-peak) between tonic and phasic REM. Moreover, the late tonic HEP component resembled the HEP found in resting wakefulness. Our results indicate that interoception with respect to cardiac signals is not uniform across REM microstates, and suggest that interoceptive processing is partially reinstated during tonic REM periods. The analyses of the HEP during REM sleep may shed new light on the organization and putative function of REM microstates.

What Is a Dream?

2020 ◽  
pp. 1-12
Author(s):  
Sue Llewellyn
Keyword(s):  
Eye Movement ◽  
Rem Sleep ◽  
Nrem Sleep ◽  
Sleep Cycle ◽  
Rapid Eye Movement ◽  
Fixed Sequence ◽  
The World ◽  
The Brain ◽  
Light Sleep

Dreaming happens during sleep. When we aren’t interacting with the world, our minds turn inwards. We dream. These dreams differ. Rapid eye movement (REM) dreams are visual, vivid, bizarre, emotional, and highly associative with embodied narratives, whereas non-rapid eye movement (NREM) dreams tend to be shorter and more thought-like. During REM dreams, the brain is as active, or even more active, than it is during wakefulness. In some dreams, during REM sleep, the dreamer is lucid—they become aware they are dreaming and can, sometimes control the dream content. These different types of dream happen at different times in the sleep cycle. Across the night, we experience NREM sleep (including light sleep and deep sleep) and REM sleep in a fixed sequence. The night isn’t a uniform period of rest. This introductory chapter explains these basic issues about sleep and dreams.

scholarly journals Control of Sleep and Wakefulness

2012 ◽  
Vol 92 (3) ◽  
pp. 1087-1187 ◽  
Author(s):  
Ritchie E. Brown ◽  
Radhika Basheer ◽  
James T. McKenna ◽  
Robert E. Strecker ◽  
Robert W. McCarley
Keyword(s):  
Brain Stem ◽  
Eye Movement ◽  
Rem Sleep ◽  
Emotional Reactivity ◽  
Low Voltage ◽  
Nrem Sleep ◽  
Gabaergic Neurons ◽  
Cortical Activation ◽  
Rapid Eye Movement ◽  
The Brain

This review summarizes the brain mechanisms controlling sleep and wakefulness. Wakefulness promoting systems cause low-voltage, fast activity in the electroencephalogram (EEG). Multiple interacting neurotransmitter systems in the brain stem, hypothalamus, and basal forebrain converge onto common effector systems in the thalamus and cortex. Sleep results from the inhibition of wake-promoting systems by homeostatic sleep factors such as adenosine and nitric oxide and GABAergic neurons in the preoptic area of the hypothalamus, resulting in large-amplitude, slow EEG oscillations. Local, activity-dependent factors modulate the amplitude and frequency of cortical slow oscillations. Non-rapid-eye-movement (NREM) sleep results in conservation of brain energy and facilitates memory consolidation through the modulation of synaptic weights. Rapid-eye-movement (REM) sleep results from the interaction of brain stem cholinergic, aminergic, and GABAergic neurons which control the activity of glutamatergic reticular formation neurons leading to REM sleep phenomena such as muscle atonia, REMs, dreaming, and cortical activation. Strong activation of limbic regions during REM sleep suggests a role in regulation of emotion. Genetic studies suggest that brain mechanisms controlling waking and NREM sleep are strongly conserved throughout evolution, underscoring their enormous importance for brain function. Sleep disruption interferes with the normal restorative functions of NREM and REM sleep, resulting in disruptions of breathing and cardiovascular function, changes in emotional reactivity, and cognitive impairments in attention, memory, and decision making.

scholarly journals Differential Gene Expression in Brain and Liver Tissue of Wistar Rats after Rapid Eye Movement Sleep Deprivation

2020 ◽  
Vol 2 (4) ◽  
pp. 442-465
Author(s):  
Atul Pandey ◽  
Ryan Oliver ◽  
Santosh K Kar
Keyword(s):  
Sleep Deprivation ◽  
Eye Movement ◽  
Rem Sleep ◽  
Liver Tissue ◽  
Rapid Eye Movement ◽  
Sleep State ◽  
Rem Sleep Deprivation ◽  
Body Tissues ◽  
Differential Gene ◽  
The Brain

Sleep is essential for the survival of most living beings. Numerous researchers have identified a series of genes that are thought to regulate “sleep-state” or the “deprived state”. As sleep has a significant effect on physiology, we believe that lack of total sleep, or particularly rapid eye movement (REM) sleep, for a prolonged period would have a profound impact on various body tissues. Therefore, using the microarray method, we sought to determine which genes and processes are affected in the brain and liver of rats following nine days of REM sleep deprivation. Our findings showed that REM sleep deprivation affected a total of 652 genes in the brain and 426 genes in the liver. Only 23 genes were affected commonly, 10 oppositely, and 13 similarly across brain and liver tissue. Our results suggest that nine-day REM sleep deprivation differentially affects genes and processes in the brain and liver of rats.

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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