Sleep regulation in rats during early development

1990 ◽  
Vol 258 (3) ◽  
pp. R634-R644 ◽  
Author(s):  
P. Alfoldi ◽  
I. Tobler ◽  
A. A. Borbely
Keyword(s):  
High Frequency ◽  
Dark Period ◽  
Power Spectra ◽  
Light Period ◽  
Rapid Eye Movement Sleep ◽  
Sleep Regulation ◽  
Age Related ◽  
High Frequency Activity ◽  
Freely Moving ◽  
Electroencephalogram Eeg

Sleep states and power spectra of the electroencephalogram (EEG) were determined in freely moving young rats. Recordings during 24 h were obtained from the same animals at three different ages. Already at the age of 23 days waking predominated in the 12-h dark period. Rapid-eye-movement sleep (REMS) declined between the age of 23 and 40 days. Its 24-h maximum was situated in the dark period at 23 and 29 days of age and in the light period at 40 days. Slow-wave activity (SWA; 0.75-4.0 Hz) of the non-REMS (NREMS) EEG showed marked age-related changes: a declining trend in the 12-h light period was absent at 23 days, moderate at 29 days, and prominent at 40 days. At 23 days, SWA progressively declined within ultradian sleep episodes and at 24 days was massively increased after 2-h sleep deprivation (SD). At the age of 30 days, 6-h SD induced much smaller changes. The distinct 24-h pattern of high-frequency activity (10.25-25.0 Hz) was present at all ages and may represent an EEG correlate of a circadian process. We conclude that homeostatic mechanisms regulating NREMS intensity are already operative a few days after weaning.

scholarly journals MicroRNA 132 alters sleep and varies with time in brain

2011 ◽  
Vol 111 (3) ◽  
pp. 665-672 ◽  
Author(s):  
Christopher J. Davis ◽  
James M. Clinton ◽  
Ping Taishi ◽  
Stewart G. Bohnet ◽  
Kimberly A. Honn ◽  
...  
Keyword(s):  
Sleep Deprivation ◽  
Eye Movement ◽  
Dark Period ◽  
Wave Activity ◽  
Light Period ◽  
Rapid Eye Movement ◽  
Rapid Eye Movement Sleep ◽  
Direct Effects ◽  
Sleep Regulation ◽  
Light Phase

MicroRNA (miRNA) levels in brain are altered by sleep deprivation; however, the direct effects of any miRNA on sleep have not heretofore been described. We report herein that intracerebroventricular application of a miRNA-132 mimetic (preMIR-132) decreased duration of non-rapid-eye-movement sleep (NREMS) while simultaneously increasing duration of rapid eye movement sleep (REMS) during the light phase. Further, preMIR-132 decreased electroencephalographic (EEG) slow-wave activity (SWA) during NREMS, an index of sleep intensity. In separate experiments unilateral supracortical application of preMIR-132 ipsilaterally decreased EEG SWA during NREMS but did not alter global sleep duration. In addition, after ventricular or supracortical injections of preMIR-132, the mimetic-induced effects were state specific, occurring only during NREMS. After local supracortical injections of the mimetic, cortical miRNA-132 levels were higher at the time sleep-related EEG effects were manifest. We also report that spontaneous cortical levels of miRNA-132 were lower at the end of the sleep-dominant light period compared with at the end of the dark period in rats. Results suggest that miRNAs play a regulatory role in sleep and provide a new tool for investigating sleep regulation.

Electroencephalogram analysis of non-rapid eye movement sleep in rats

1988 ◽  
Vol 255 (1) ◽  
pp. R27-R37 ◽  
Author(s):  
L. Trachsel ◽  
I. Tobler ◽  
A. A. Borbely
Keyword(s):  
Eye Movement ◽  
Slow Wave ◽  
Power Spectra ◽  
Low Frequency ◽  
Wave Activity ◽  
Slow Wave Activity ◽  
Rapid Eye Movement ◽  
Rapid Eye Movement Sleep ◽  
Episode Duration ◽  
High Frequency Activity

Sleep states and power spectra of the electroencephalogram were determined for consecutive 4-s epochs during 24 h in rats that had been implanted with electrodes under deep pentobarbital anesthesia. The power spectra in non-rapid eye movement sleep (NREMS) showed marked trends: low-frequency activity (0.75-7.0 Hz) declined progressively throughout the 12-h light period (L) and remained low during most of the 12-h dark period (D); high-frequency activity (10.25-25.0 Hz) rose toward the end of L and reached a maximum at the beginning of D. Within a single NREMS episode (duration 0.5-5.0 min), slow-wave activity (0.75-4.0 Hz) increased progressively to a plateau level. The rise was approximated by a saturating exponential function: although the asymptote level of the function showed a prominent 24-h rhythm, the time constant remained relatively stable (approximately 40 s). After short interruptions of NREMS episodes, slow-wave activity rose more steeply than after long interruptions. The marked 24-h variation of maximum slow-wave activity within NREMS episodes may reflect the level of a homeostatic sleep process.

Sleep and hibernation in ground squirrels (Citellus spp): electrophysiological observations

1977 ◽  
Vol 233 (5) ◽  
pp. R213-R221 ◽  
Author(s):  
J. M. Walker ◽  
S. F. Glotzbach ◽  
R. J. Berger ◽  
H. C. Heller
Keyword(s):  
Rem Sleep ◽  
Slow Wave Sleep ◽  
Dark Period ◽  
Total Sleep Time ◽  
Brain Temperature ◽  
Sleep Time ◽  
Light Period ◽  
Ground Squirrels ◽  
Sleep Stages ◽  
Electroencephalogram Eeg

Electroencephalogram (EEG), electrooculogram, electromyogram, and electrocardiogram were recorded from ground squirrels (Citellus beldingi and C. lateralis) during the summer and also during the hibernation season. Summer recordings revealed that the animals spent an average of 66% of the 24-h period asleep (49% of the 12-h light period and 84% of the 12-h dark period); 19% of the total sleep time (TST) consisted of rapid-eye-movement (REM) sleep, and 81% of TST consisted of slow-wave sleep (SWS). Recordings obtained during the hibernation season showed that hibernation was entered through sleep, but the distribution of sleep states was different than in euthermic sleep. During the early entrance when brain temperature (Tbr) was between 35 and 25 degrees C, the animals were asleep 88% of the time, but only 10% of the TST was spent in REM sleep. The EEG amplitude declined with decreased Tbr so that classical sleep stages could not be identified below a Tbr of 25 degrees C. The frequency of the EEG increased as Tbr decreased; but activity in the 0–4 cycles/s band occupied the majority of the record even at a Tbr of 10 degrees C. Below a Tbr of 10 degrees C the EEG was isoelectric except for intermittent bursts of spindles. It was concluded from these and other results that the entrance into hibernation represents an extension of the thermoregulatory adjustments that occur during SWS.

Dynamics of the sleep EEG after an early evening nap: experimental data and simulations

1996 ◽  
Vol 271 (3) ◽  
pp. R501-R510 ◽  
Author(s):  
E. Werth ◽  
D. J. Dijk ◽  
P. Achermann ◽  
A. A. Borbely
Keyword(s):  
Power Density ◽  
Time Course ◽  
Sleep Eeg ◽  
Rapid Eye Movement Sleep ◽  
Theta Band ◽  
Sleep Regulation ◽  
Homeostatic Model ◽  
Nighttime Sleep ◽  
Electroencephalogram Eeg ◽  
Homeostatic Mechanisms

Increasing sleep pressure is associated with highly predictable changes in the dynamics of the sleep electroencephalogram (EEG). To investigate whether the effects of reduced sleep pressure also can be accounted for by homeostatic mechanisms, nighttime sleep following an evening nap was recorded in healthy young men. In comparison with the baseline night, sleep latency in the postnap night was prolonged, rapid eye movement sleep (REMS) latency was reduced, and EEG power density in non-REMS was decreased in the delta and theta band. The buildup of both EEG slow-wave activity (SWA; power density in the 0.75-to 4.5-Hz range) and spindle frequency activity (SFA; power density in the 12.25-to 15.0-Hz range) in non-REMS episodes was diminished (SWA: episodes 1-3; SFA: episode 1). The typical declining trend of SWA over consecutive non-REM sleep episodes was attenuated. The time course of SWA could be closely simulated with a homeostatic model of sleep regulation, although some discrepancies in level and buildup of SWA were apparent. We conclude that homeostatic mechanisms can largely account for the dynamics of the sleep EEG under conditions of reduced sleep pressure.

scholarly journals Effect of Restricted Feeding on Metabolic Health and Sleep-Wake Rhythms in Aging Mice

2021 ◽  
Vol 15 ◽  
Author(s):  
Yong-Xia Xu ◽  
Guo-Ying Liu ◽  
Qian Jiang ◽  
Han-Qi Bi ◽  
Shi-Chan Wang ◽  
...  
Keyword(s):  
Older Adults ◽  
Blood Glucose ◽  
Dark Period ◽  
Metabolic Health ◽  
Light Period ◽  
Restricted Feeding ◽  
Dietary Regimen ◽  
Aged Mice ◽  
Age Related ◽  
Significant Difference

Aging, an irreversible and unavoidable physiological process in all organisms, is often accompanied by obesity, diabetes, cardiovascular diseases, sleep disorders, and fatigue. Thus, older adults are more likely to experience metabolic symptoms and sleep disturbances than are younger adults. Restricted feeding (RF) is a dietary regimen aimed at improving metabolic health and extending longevity, as well as reorganizing sleep-wake cycles. However, the potential of RF to improve metabolic health and sleep quality in older adults who are known to show a tendency toward increased weight gain and decreased sleep is unknown. To elucidate this issue, aged mice were assigned to an RF protocol during the active phase for 2 h per day for 2 weeks. Sleep-wake cycles were recorded during the RF regime in RF group and control mice. At the end of this period, body weight and blood biochemistry profiles, including blood glucose, cholesterol, and enzyme activity, in addition to dopamine concentrations in the brain, were measured in the RF group and age-matched controls. RF for 2 weeks improved the metabolic health of aged mice by reducing their body weights and blood glucose and cholesterol levels. At the beginning of the RF regime, sleep decreased in the dark period but not in the light period. After stable food entrainment was achieved (7 days post-RF commencement), the amount of time spent in wakefulness during the light period dramatically increased for 2 h before food availability, thereby increasing the mean duration of awake episodes and decreasing the number of wakefulness episodes. There was no significant difference in the sleep-wake time during the dark period in the RF group, with similar total amounts of wakefulness and sleep in a 24-h period to those of the controls. During the RF regime, dopamine levels in the midbrain increased in the RF group, pointing to its potential as the mechanism mediating metabolic symptoms and sleep-wake regulation during RF. In conclusion, our study suggested that RF during aging might prohibit or delay the onset of age-related diseases by improving metabolic health, without having a severe deleterious effect on sleep.

State-dependent effects of light-dark cycle on somatosensory and visual cortex EEG in rats

2005 ◽  
Vol 289 (4) ◽  
pp. R1083-R1089 ◽  
Author(s):  
Tadanobu Yasuda ◽  
Kyo Yasuda ◽  
Richard A. Brown ◽  
James M. Krueger
Keyword(s):  
Visual Cortex ◽  
Dark Period ◽  
Afferent Input ◽  
Light Period ◽  
Wave Band ◽  
Rapid Eye Movement Sleep ◽  
State Dependent ◽  
Eeg Power ◽  
Wake State ◽  
Constant Dark

Somatosensory (SSctx) and visual cortex (Vctx) EEG were evaluated in rats under a 12:12-h light-dark (LD) cycle and under constant light (LL) or constant dark (DD) in each sleep or wake state. Under LD conditions during light period, relative Vctx EEG slow-wave activity (SWA) was higher than that of the SSctx, whereas during dark period, relative Vctx EEG SWA was lower than in the SSctx. These effects were state specific, occurring only during non-rapid eye movement sleep (NREMS). Under LL conditions, the duration of REMS and NREMS during the period that would have been dark if the LD cycle had continued (subjective dark period) was greater than under LD conditions. DD conditions had little effect on the duration of NREMS and REMS. SSctx and Vctx EEG SWA were suppressed by LL during the subjective dark period; however, the degree of Vctx SWA suppression was smaller than that of the SSctx. DD conditions during the subjective light period enhanced SSctx SWA, whereas Vctx SWA was suppressed. Under LL conditions during the subjective dark period, Vctx EEG power was higher than that of the SSctx across a broad frequency range during NREMS, REMS, and wakefulness. During DD, SSctx EEG power during NREMS was higher than that of the Vctx in the delta wave band, whereas SSctx power during REMS and wakefulness was higher than that of the Vctx in frequencies higher than 8 Hz. We concluded that the SSctx and Vctx EEGs are differentially affected by light during subsequent sleep. Results provide support for the notion that regional sleep intensity is dependent on prior regional afferent input.

Sleep changes induced by lipopolysaccharide in the rat are influenced by age

2001 ◽  
Vol 280 (2) ◽  
pp. R398-R403 ◽  
Author(s):  
Thomas Schiffelholz ◽  
Marike Lancel
Keyword(s):  
Wave Activity ◽  
Immune Challenge ◽  
Aged Rats ◽  
Rapid Eye Movement Sleep ◽  
Middle Aged ◽  
Age Related ◽  
Sleep Alterations ◽  
Electroencephalogram Eeg ◽  
Elevated Body Temperature ◽  
Age Related Changes

In mammals, aging is associated with immune senescense. To examine whether the sleep changes occurring during immune challenge are affected by age, we assessed sleep alterations induced by the administration of lipopolysaccharide (LPS) in young and middle-aged rats. During vehicle, the middle-aged rats exhibited less pre-rapid eye movement sleep (pre-REMS) as well as REMS, due to a smaller number and shorter duration of REMS episodes, than young rats. LPS elevated body temperature, increased non-REMS, and suppressed both pre-REMS and REMS in the young as well as in the middle-aged rats. However, in the young animals, LPS significantly enhanced slow-wave activity in the electroencephalogram (EEG) within non-REMS, reflecting an increase in sleep intensity. In contrast, LPS attenuated EEG power in most frequency bands in the older animals. This finding indicates age-related changes in the modulation of sleep by LPS.

Polysomnographic Findings in Nights Preceding a Migraine Attack

Cephalalgia ◽  
2001 ◽  
Vol 21 (1) ◽  
pp. 31-37 ◽  
Author(s):  
R Göder ◽  
G Fritzer ◽  
A Kapsokalyvas ◽  
P Kropp ◽  
U Niederberger ◽  
...  
Keyword(s):  
Slow Wave Sleep ◽  
Power Spectra ◽  
Cortical Activation ◽  
Alpha Power ◽  
Sleep Regulation ◽  
Beta Power ◽  
Rem Density ◽  
Sleep Parameters ◽  
Sleep Alterations ◽  
Electroencephalogram Eeg

Sleep recordings were performed in eight patients to analyse sleep alterations preceding migraine attacks. Polysomnographic recordings from nights before an attack were compared with nights without following migraine. We analysed standard sleep parameters and electroencephalogram (EEG) power spectra. The main findings preceding migraine attacks were a significant decrease in the number of arousals, a decrease in rapid eye movement (REM) density, a significant decrease of beta power in the slow wave sleep, and a decrease of alpha power during the first REM period. The results suggest a decrease in cortical activation during sleep preceding migraine attacks. According to the models of sleep regulation, alterations in the function of aminergic or cholinergic brainstem nuclei have to be discussed.

Sleep of transgenic mice producing excess rat growth hormone

2002 ◽  
Vol 282 (1) ◽  
pp. R70-R76 ◽  
Author(s):  
I. Hajdu ◽  
F. Obal ◽  
J. Fang ◽  
J. M. Krueger ◽  
C. D. Rollo
Keyword(s):  
Growth Hormone ◽  
Transgenic Mice ◽  
Eye Movement ◽  
Hormonal Changes ◽  
Rapid Eye Movement ◽  
Rapid Eye Movement Sleep ◽  
Sleep Regulation ◽  
Rat Growth ◽  
Electroencephalogram Eeg

The effects of chronic excess of growth hormone (GH) on sleep-wake activity was determined in giant transgenic mice in which the metallothionein-1 promoter stimulates the expression of rat GH (MT-rGH mice) and in their normal littermates. In the MT-rGH mice, the time spent in spontaneous non-rapid eye movement sleep (NREMS) was enhanced moderately, and rapid eye movement sleep (REMS) time increased greatly during the light period. After a 12-h sleep deprivation, the MT-rGH mice continued to sleep more than the normal mice, but there were no differences in the increments in NREMS, REMS, and electroencephalogram (EEG) slow-wave activity (SWA) during NREMS between the two groups. Injection of the somatostatin analog octreotide elicited a prompt sleep suppression followed by increases in SWA during NREMS in normal mice. These changes were attenuated in the MT-rGH mice. The decreased responsiveness to octreotide is explained by a chronic suppression of hypothalamic GH-releasing hormone in the MT-rGH mice. Enhancements in spontaneous REMS are attributed to the REMS-promoting activity of GH. The increases in spontaneous NREMS are, however, not consistent with our current understanding of the role of somatotropic hormones in sleep regulation. Metabolic, neurotransmitter, or hormonal changes associated with chronic GH excess may indirectly influence sleep.

Selective Shunting During Carotid Endarterectomy Based on Two-Channel Computerized Electroencephalographic/Compressed Spectral Array Analysis

Neurosurgery ◽  
1989 ◽  
Vol 24 (3) ◽  
pp. 339-344 ◽  
Author(s):  
Rene Tempelhoff ◽  
Paul A. Modica ◽  
Robert L. Grubb ◽  
Keith M. Rich ◽  
Barbel Holtmann
Keyword(s):  
High Frequency ◽  
Eeg Monitoring ◽  
Array Analysis ◽  
Amplitude Attenuation ◽  
Neurological Exam ◽  
On Line ◽  
High Frequency Activity ◽  
Computerized Eeg ◽  
Electroencephalogram Eeg ◽  
Angiographic Findings

Abstract The reliability of selective shunting based on computerized electroencephalographic (EEG) monitoring has not been addressed. In this study, 103 carotid endarterectomies were performed with selective shunting based on a two-channel computerized EEG monitor that processed the on-line, raw electroencephalogram (EEG) to produce a compressed spectral array (CSA). Ischemic EEG events were identified by amplitude attenuation of the raw EEG and/or loss of high-frequency activity on the CSA. Fourteen patients (13.6%) received a bypass shunt, and postoperative neurological examinations showed 97 patients (94.2%) to be intact. A correlation between total (cumulative) ischemic EEG time and the postoperative neurological exam was demonstrated (P < 0.0001). Six postoperative deficits (5.8%) occurred, five in patients whose computerized EEGs demonstrated an ischemic EEG event late during carotid clamping, when it was no longer possible to place a shunt. The sixth deficit was found in a patient whose EEG did not demonstrate any signs of cerebral ischemia. Five of these six new deficits resolved within 12 hours, and only one persisted for 72 hours, when the patient died of a pulmonary embolism (cerebral infarction and mortality rate of 1%). These results appear to demonstrate that two-channel monitoring of both the CSA and the unprocessed (raw) EEG simultaneously can be used as a reliable indicator of whether a bypass shunt is required during carotid cross-clamping in all patients, regardless of their preoperative neurological history or angiographic findings.

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