Composition and replay of mnemonic sequences: The contributions of REM and slow-wave sleep to episodic memory

2013 ◽  
Vol 36 (6) ◽  
pp. 610-611 ◽  
Author(s):  
Sen Cheng ◽  
Markus Werning

AbstractWe propose that rapid eye movement (REM) and slow-wave sleep contribute differently to the formation of episodic memories. REM sleep is important for building up invariant object representations that eventually recur to gamma-band oscillations in the neocortex. In contrast, slow-wave sleep is more directly involved in the consolidation of episodic memories through replay of sequential neural activity in hippocampal place cells.

2021 ◽  
Vol 11 (4) ◽  
pp. 410
Author(s):  
Simon Ruch ◽  
Kristoffer Fehér ◽  
Stephanie Homan ◽  
Yosuke Morishima ◽  
Sarah Maria Mueller ◽  
...  

Slow-wave sleep (SWS) has been shown to promote long-term consolidation of episodic memories in hippocampo–neocortical networks. Previous research has aimed to modulate cortical sleep slow-waves and spindles to facilitate episodic memory consolidation. Here, we instead aimed to modulate hippocampal activity during slow-wave sleep using transcranial direct current stimulation in 18 healthy humans. A pair-associate episodic memory task was used to evaluate sleep-dependent memory consolidation with face–occupation stimuli. Pre- and post-nap retrieval was assessed as a measure of memory performance. Anodal stimulation with 2 mA was applied bilaterally over the lateral temporal cortex, motivated by its particularly extensive connections to the hippocampus. The participants slept in a magnetic resonance (MR)-simulator during the recordings to test the feasibility for a future MR-study. We used a sham-controlled, double-blind, counterbalanced randomized, within-subject crossover design. We show that stimulation vs. sham significantly increased slow-wave density and the temporal coupling of fast spindles and slow-waves. While retention of episodic memories across sleep was not affected across the entire sample of participants, it was impaired in participants with below-average pre-sleep memory performance. Hence, bi-temporal anodal direct current stimulation applied during sleep enhanced sleep parameters that are typically involved in memory consolidation, but it failed to improve memory consolidation and even tended to impair consolidation in poor learners. These findings suggest that artificially enhancing memory-related sleep parameters to improve memory consolidation can actually backfire in those participants who are in most need of memory improvement.


1978 ◽  
Vol 45 (5) ◽  
pp. 681-689 ◽  
Author(s):  
C. E. Sullivan ◽  
E. Murphy ◽  
L. F. Kozar ◽  
E. A. Phillipson

We studied waking and ventilatory responses to laryngeal stimulation during sleep in three dogs. The dogs breathed through an endotracheal tube inserted caudally into the trachea through a tracheostomy. Laryngeal stimulation was produced either by inflating a small balloon that was positioned in the rostral tracheal segment, or by squirting water onto the larynx through a catheter inserted through the tracheostomy. Airflow was measured with a pneumotachograph, and sleep state was determined by behavioral, electroencephalographic, and electromyographic criteria. We found that the degree of laryngeal stimulation required to produce arousal and coughing was higher in rapid-eye-movement (REM) sleep than in slow-wave sleep (SWS). Stimuli that failed to cause arousal from SWS often produced a single expiratory effort, or brief apnea (1--2 s) and bradycardia. In contrast, during REM sleep subarousal stimuli often resulted in prolonged apnea (greater than 10 s) and marked bradycardia. We conclude that during REM sleep arousal responses to laryngeal stimulation are depressed, but ventilatory and cardiac responses are intact.


1986 ◽  
Vol 250 (1) ◽  
pp. R96-R103 ◽  
Author(s):  
J. Walter ◽  
D. Davenne ◽  
S. Shoham ◽  
C. A. Dinarello ◽  
J. M. Krueger

The effects of human interleukin 1 (IL 1) on the architecture of rabbit sleep-wake cycles and brain temperature (Tbr) changes coupled to states of vigilance were examined. Cerebral intraventricular infusion of IL 1 induced increased slow-wave sleep (SWS), increased electroencephalographic slow-wave (0.5-4 Hz) amplitudes, and fever. Heat-inactivated IL 1 failed to elicit these responses. IL 1 also significantly inhibited rapid-eye-movement (REM) sleep; however, inactivated IL 1 also reduced REM sleep; thus some of the IL 1-induced REM reduction may be related to the infusion process. The duration and number of sleep cycles (REM-to-REM interval) were unaffected by IL 1. Similarly, Tbr changes that normally occur during the transition from one arousal state to another remained unchanged after IL 1 infusion, even though rabbits were simultaneously febrile. We conclude that IL 1 selectively enhances SWS while leaving sleep cycles and Tbr changes coupled to states of vigilance undisturbed.


1973 ◽  
Vol 4 (2) ◽  
pp. 201-212 ◽  
Author(s):  
Vincent P. Zarcone

Both marijuana and alcohol have effects on sleep which can be clinically important if either drug is used heavily. A number of polygraphic studies of both drugs' effect on sleep demonstrate that both are rapid eye movement (REM) sleep suppressors and that both effect the REM sleep deprivation response for days after the acute effects have ceased. Marijuana also increases slow wave sleep compared to alcohol which decreases it. The studies reviewed indicate that marijuana, like alcohol, has persisting effects on neuronal activity and presumably on its underlying neurochemical regulation. Also, the studies suggest that caution should be employed in advising the public about the use of marijuana.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jin-Xiang Cheng ◽  
Jiafeng Ren ◽  
Jian Qiu ◽  
Yingcong Jiang ◽  
Xianchao Zhao ◽  
...  

AbstractThis study aimed to investigate the clinical characteristics and predictors of increased rapid eye movement (REM) sleep or slow wave sleep (SWS) in patients with obstructive sleep apnea (OSA) following positive airway pressure (PAP) therapy. The study retrospectively analyzed data from patients with OSA who underwent both diagnostic polysomnography (PSG) and pressure titration PSG at the Tangdu Hospital Sleep Medicine Center from 2011–2016. Paired diagnostic PSG and pressure titration studies from 501 patients were included. REM rebound was predicted by a higher oxygen desaturation index, lower REM proportion, higher arousal index, lower mean pulse oxygen saturation (SpO2), higher Epworth sleepiness score and younger age (adjusted R2 = 0.482). The SWS rebound was predicted by a longer total duration of apneas and hypopneas, lower N3 duration, lower SpO2 nadir, lower REM proportion in diagnostic PSG and younger age (adjusted R2 = 0.286). Patients without REM rebound or SWS rebound had a high probability of comorbidities with insomnia and mood complaints. Some parameters (subjective and objective insomnia, excessive daytime sleepiness, age and OSA severity) indicate changes in REM sleep and SWS between diagnostic and titration PSG tests. Treatment of insomnia and mood disorders in patients with OSA may helpful to improve the use PAP.


2020 ◽  
Vol 375 (1799) ◽  
pp. 20190655 ◽  
Author(s):  
M. J. Eckert ◽  
B. L. McNaughton ◽  
M. Tatsuno

Neural activity patterns of recent experiences are reactivated during sleep in structures critical for memory storage, including hippocampus and neocortex. This reactivation process is thought to aid memory consolidation. Although synaptic rearrangement dynamics following learning involve an interplay between slow-wave sleep (SWS) and rapid eye movement (REM) sleep, most physiological evidence implicates SWS directly following experience as a preferred window for reactivation. Here, we show that reactivation occurs in both REM and SWS and that coordination of REM and SWS activation on the same day is associated with rapid learning of a motor skill. We performed 6 h recordings from cells in rats' motor cortex as they were trained daily on a skilled reaching task. In addition to SWS following training, reactivation occurred in REM, primarily during the pre-task rest period, and REM and SWS reactivation occurred on the same day in rats that acquired the skill rapidly. Both pre-task REM and post-task SWS activation were coordinated with muscle activity during sleep, suggesting a functional role for reactivation in skill learning. Our results provide the first demonstration that reactivation in REM sleep occurs during motor skill learning and that coordinated reactivation in both sleep states on the same day, although at different times, is beneficial for skill learning. This article is part of the Theo Murphy meeting issue ‘Memory reactivation: replaying events past, present and future’.


1983 ◽  
Vol 244 (1) ◽  
pp. R114-R118 ◽  
Author(s):  
J. M. Walker ◽  
L. E. Walker ◽  
D. V. Harris ◽  
R. J. Berger

Electrophysiological sleep patterns, respiration frequency, brain temperature (Tbr), and ear temperature (Tear) were recorded from five pocket mice (Perognathus longimembris) exposed to ambient temperatures (Ta) of 22.5, 27.5, 32.5, and 35.0 degrees C. Thermoregulation was curtailed during rapid-eye-movement (REM) sleep, since Tbr declined following REM onsets at Ta's below thermoneutrality and increased at Ta's above thermoneutrality. Tbr subsequently returned to pre-REM levels following the termination of each REM episode. Respiratory frequency was inversely related to Ta but not as strongly during REM sleep as during slow-wave sleep (SWS). These results confirm previous reports of loss of thermoregulatory ability during REM sleep. Mean duration and proportions of wakefulness, SWS, and REM sleep were unaffected by Ta, consistent with earlier findings on ground squirrels, but differing from reports of decreased REM sleep in nonhibernators. Hibernators may have lower peripheral thermosensitivities than nonhibernators, facilitating sleep at low ambient temperatures and during entrance into hibernation.


1979 ◽  
Vol 42 (1) ◽  
pp. 214-228 ◽  
Author(s):  
R. P. Vertes

1. The activity of 44 single brain stem gigantocellular neurons was recorded in the freely moving rat during the following four states: quiet waking (W), waking with movement (W-M), slow-wave sleep (SWS), and rapid eye movement (REM) sleep. 2. Cells were classified into three groups on the basis of the states in which they maintained their highest rate of discharge. The three cell categories were: movement-REM (MOV-REM), movement (MOV), and quiet waking (QW) neurons. The MOV-REM neurons, comprising 68% of the cell population, discharged significantly more during waking-movement and REM sleep than during either W or SWS. The MOV neurons, 16% of the cells, showed significant increases in activity only when the rat moved. The QW neurons, also 16% of the cells, typically maintained high rates of discharge in the absence of movement. 3. The MOV-REM neurons were further divided into two subclasses of cells--phasically and tonically discharging neurons. The phasic MOV-REM cells appeared to participate in phasic motor events of REM sleep and corresponding movements during waking. The pattern of activity of the tonic MOV-REM neurons suggested that they may be involved in the generation and maintenance of the theta rhythm of the hippocampus during waking-movement and REM sleep. 4. No cells were found to discharge significantly more in REM sleep or SWS sleep than in the other states, (i.e., no REM or SWS selective cells were seen).


1987 ◽  
Vol 62 (5) ◽  
pp. 1832-1836 ◽  
Author(s):  
F. G. Issa ◽  
S. G. McNamara ◽  
C. E. Sullivan

Previous studies have shown that the arousal threshold to hypoxia, hypercapnia, and tracheal occlusions is greatly depressed in rapid-eye-movement (REM) sleep compared with slow-wave sleep (SWS). The aim of this study was to compare the arousal thresholds in SWS and REM sleep in response to an upper airway pressure stimulus. We compared the waking responses to tracheal (T) vs. nasal (N) occlusion in four unanesthetized, naturally sleeping dogs. The dogs either breathed through a tracheal fistula or through the snout using a fiberglass mask. A total of 295 T and 160 N occlusion tests were performed in SWS and REM sleep. The mean time to arousal during N and T tests was variable in the same dog and among the dogs. The mean time to arousal in SWS-tracheal occlusion was longer than that in N tests in only two of the four dogs. The total number of tests inducing arousal within the first 15 s of SWS-nasal occlusion tests was significantly more than that of T tests (N: 47%; T: 27%). There was a marked depression of arousal within the initial 15 s of REM sleep in T tests compared with N tests (N: 21%; T: 0%). The frequency of early arousals in REM tests was less than that of SWS for both N and T tests. The early arousal in N occlusion is in sharp contrast to the well-described depressed arousal responses to hypoxia, hypercapnia, and asphyxia. This pattern of arousal suggests that the upper airway mechanoreceptors may play an important role in the induction of an early arousal from nasal occlusion.


1977 ◽  
Vol 55 (2) ◽  
pp. 234-242 ◽  
Author(s):  
M. Rezek ◽  
V. Havlicek ◽  
L. Leybin ◽  
C. Pinsky ◽  
E. A. Kroeger ◽  
...  

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).


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