REM Sleep Deprivation Research Articles

The effects of citalopram, SB-334867 and orexin-1, alone or in various combinations, on the anxiogenic-like effects of REM sleep deprivation in male mice.

Sleep deprivation may induce anxiety. On the other hand, anxiety disorders elicit main changes in the quality of sleep. Moreover, orexin and citalopram play a role in the modulation of insomnia and mood diseases. Thus, we planned preclinical research to evaluate the effect of combinations of orexin agents and citalopram on anxiety behavior in rapid eye movement (REM) sleep-deprived mice. For drug intracerebroventricular (i.c.v.) infusion, the guide cannula was surgically implanted in the left lateral ventricle of mice. REM sleep deprivation was conducted via water tank apparatus for 24 h. The anxiety behavior of mice was evaluated using the elevated plus maze (EPM). Our results revealed that REM sleep deprivation reduced the percentage of open arm time (%OAT) and the percentage of the open arm entries (%OAE) but not closed arm entries (locomotor activity) in the EPM test, presenting an anxiogenic response ( P < 0.05). We found a sub-threshold dose of SB-334867, orexin-1 receptor antagonist, and orexin-1 which did not alter anxiety reaction in the REM sleep-deprived mice ( P > 0.05). Intraperitoneal (i.p.) injections of citalopram (5 and 10 mg/kg) increased both %OAT and %OAE ( P < 0.001) representing an anxiolytic effect, but not locomotor activity in the REM sleep-deprived mice. Interestingly, co-treatment of citalopram (1, 5 and 10 mg/kg; i.p.) and SB-334867 (0.1 µg/mouse; i.c.v.) potentiated the anxiolytic effect in the REM sleep-deprived mice. On the other hand, co-treatment of different dosages of citalopram along with a sub-threshold dose of orexin-1 did not alter %OAT, %OAE, and locomotor activity in the REM sleep-deprived mice. We found a synergistic anxiolytic effect of citalopram and SB-334867 in the REM sleep-deprived mice. These results suggested an interaction between citalopram and SB-334867 to prevent anxiogenic behavior in the REM sleep-deprived mice.

Activation of dopamine D2 receptors attenuates neuroinflammation and ameliorates the memory impairment induced by rapid eye movement sleep deprivation in a murine model.

The proinflammatory state, which may be induced by sleep deprivation, seems to be a determining factor in the development of neurodegenerative processes. Investigations of mechanisms that help to mitigate the inflammatory effects of sleep disorders are important. A new proposal involves the neurotransmitter dopamine, which may modulate the progression of the immune response by activating receptors expressed on immune cells. This study aimed to determine whether dopamine D2 receptor (D2DR) activation attenuates the proinflammatory response derived from rapid eye movement (REM) sleep deprivation in mice. REM sleep deprivation (RSD) was induced in 2-month-old male CD1 mice using the multiple platform model for three consecutive days; during this period, the D2DR receptor agonist quinpirole (QUIN) was administered (2 mg/kg/day i.p.). Proinflammatory cytokine levels were assessed in serum and homogenates of the brain cortex, hippocampus, and striatum using ELISAs. Long-term memory deficits were identified using the Morris water maze (MWM) and novel object recognition (NOR) tests. Animals were trained until learning criteria were achieved; then, they were subjected to RSD and treated with QUIN for 3 days. Memory evocation was determined afterward. Moreover, we found RSD induced anhedonia, as measured by the sucrose consumption test, which is commonly related to the dopaminergic system. Our data revealed increased levels of proinflammatory cytokines (TNFα and IL-1β) in both the hippocampus and serum from RSD mice. However, QUIN attenuated the increased levels of these cytokines. Furthermore, RSD caused a long-term memory evocation deficit in both the MWM and NOR tests. In contrast, QUIN coadministration during the RSD period significantly improved the performance of the animals. On the other hand, QUIN prevented the anhedonic condition induced by RSD. Based on our results, D2DR receptor activation protects against memory impairment induced by disturbed REM sleep by inhibiting neuroinflammation.

Oxidative Stress Induces Endothelial Dysfunction and Endothelial Cell Damage in Rapid Eye Movement (REM) Sleep Deprivation Animal Model

INTRODUCTION: Rapid eye movement (REM) sleep deprivation causes oxidative stress, leading to endothelial dysfunction, a predictor of cardiovascular disease. It is still unclear what causes endothelial dysfunction in patients with sleep disorder. This study evaluates the effects of REM sleep deprivation on the endothelium in the rat model of REM sleep deprivation. MATERIALS AND METHODS: Sprague-Dawley male rats (N=28) were divided into four groups (n=7); (1) free-moving control (FMC), (2) REM sleep deprivation (REMsd), (3) tank control (TC), and (4) sleep recovery (SR). The inverted flowerpot technique was utilised to develop REM sleep deprivation. Bodyweight gain (BWg), food consumption (Fc), and systolic blood pressure (SBP) were evaluated. The descending thoracic aorta was isolated to assess oxidative stress markers, in vitro functional study, and histomorphological examination. RESULTS: REM sleep deprivation showed a decrease in BWg significantly despite a significant increase in Fc, increased SBP, increased oxidative stress markers, caused endothelial dysfunction and endothelial cell damage. In REM sleep-deprived rats, there was a significant reduction in antioxidant markers, including total antioxidant capacity (TAC), superoxide dismutase (SOD) activity, catalase (CAT), and glutathione (GSH), while the levels of malondialdehyde (MDA) were significantly increased. The REM sleep-deprived rats displayed altered vascular function, including impaired vasorelaxation and hypercontractility. Histomorphology of the endothelium in REM sleep-deprived rats revealed features of endothelial damage. CONCLUSION: REM sleep deprivation is suggested to be linked to endothelial dysfunction due to endothelial damage. These changes are proposed to result from increased oxidative stress. Sleep recovery reduced the harmful effects following REM sleep deprivation.

Lithium Treatment Improves Cardiac Dysfunction in Rats Deprived of Rapid Eye Movement Sleep.

Rapid eye movement (REM) sleep deprivation triggers mania and induces cardiac fibrosis. Beyond neuroprotection, lithium has cardioprotective potential and antifibrotic activity. This study investigated whether lithium improved REM sleep deprivation-induced cardiac dysfunction and evaluated the potential mechanisms. Transthoracic echocardiography, histopathological analysis, and Western blot analysis were performed in control and REM sleep-deprived rats with or without lithium treatment (LiCl of 1 mmol/kg/day administered by oral gavage for 4 weeks) in vivo and in isolated ventricular preparations. The results revealed that REM sleep-deprived rats exhibited impaired contractility and greater fibrosis than control and lithium-treated REM sleep-deprived rats. Western blot analysis showed that REM sleep-deprived hearts had higher expression levels of transforming growth factor beta (TGF-β), phosphorylated Smad 2/3, and alpha-smooth muscle actin than lithium-treated REM sleep-deprived and control hearts. Moreover, lithium-treated REM sleep-deprived hearts had lower expression of angiotensin II type 1 receptor, phosphorylated nuclear factor kappa B p65, calcium release-activated calcium channel protein 1, transient receptor potential canonical (TRPC) 1, and TRPC3 than REM sleep-deprived hearts. The findings suggest that lithium attenuates REM sleep deprivation-induced cardiac fibrogenesis and dysfunction possibly through the downregulation of TGF-β, angiotensin II, and Ca2+ signaling.

Synergistic antidepressant effects of citalopram and SB-334867 in the REM sleep-deprived mice: Possible role of BDNF

This study was done to evaluate the effect of co-treatment of orexin agents along with citalopram on the modulation of depression-like behavior and the expression of BDNF in the prefrontal cortex (PFC) of sleep-deprived male mice. A sleep deprivation model was performed in which rapid eye movement (REM) sleep was completely prohibited, and non-REM sleep was intensely reduced for 24 h. For drug microinjection, the guide cannula was surgically fixed in the left lateral ventricle of mice. Furthermore, we used the open-field test (OFT), forced swim test (FST), tail suspension test (TST), and splash test for recording depression-like behavior as well as Real-Time PCR amplification for assessing the expression of BDNF in the PFC of REM sleep-deprived mice. Our results revealed that REM sleep deprivation did not change locomotor activity while increased depressive-like behavior in FST, TST, and splash tests. However, the expression of BDNF was decreased in the PFC. Intraperitoneally (i.p.) administration of citalopram induced antidepressant effect in the normal and REM sleep-deprived mice. Moreover, intracerebroventricular (i.c.v.) microinjection of a non-effective dose of SB-334867, an orexin antagonist, potentiated the antidepressant-like effect of citalopram.On the other hand, a non-significant dosage of orexin-1 reversed the antidepressant effect of citalopram in the normal and REM sleep-deprived animals. Furthermore, our results showed that injection of citalopram alone or with SB-334867 increased the mRNA expression level of BDNF in the PFC of REM sleep-deprived mice. These data suggest that REM sleep deprivation interferes with the neural systems underlying the depression-like process and supports a likely interaction of the orexin system with citalopram on the modulation of depression-like behavior in REM sleep-deprived mice.

Effects of uridine administration on hippocampal matrix metalloproteinases and their endogenous inhibitors in REM sleep-deprived rats

Rapid eye movement (REM) sleep is associated with synaptic plasticity which is considered essential for long-term potentiation (LTP). The composition of extracellular matrix (ECM), in part, plays a role in REM sleep-associated synaptic functioning. The objective of this study was to investigate the effects of uridine administration on levels of matrix metalloproteinases (MMPs) and their endogenous inhibitors (TIMPs) in rats subjected to REM sleep deprivation (REMSD). REMSD was induced by modified multiple platform method for 96-hour. Rats were randomized to receive either saline or uridine (1 mmol/kg) intraperitoneally twice a day for four days. Rats were then decapitated and their hippocampi were dissected for analyzing the levels of MMP-2, MMP-3, MMP-9, TIMP-1, TIMP-2 and TIMP-3 by Western-blotting and the activities of MMP-2 and MMP-9 by Gelatin zymography. REMSD resulted in reduced levels of MMP-3, MMP-9, TIMP-3 and activity of MMP-9 in saline-treated rats, while uridine treatment significantly enhanced their impairment. TIMP-1 was enhanced following REMSD but uridine treatment had no significant effect on TIMP-1 levels. MMP-2, TIMP-2 levels and MMP-2 activity were not affected by either REMSD or uridine administration. These data show that REMSD significantly affects ECM composition which is ameliorated by uridine administration suggesting a possible use of uridine in sleep disorders.

Intraperitoneal ozone injection prevents REM sleep deprivation - induced spatial learning and memory deficits by suppressing the expression of Sema3A in the hippocampus in rats.

Objective(s):Sleep deprivation is a common health problem in modern society and is negatively associated with deleterious effects on cognitive functions such as learning and memory ability. This study was undertaken to provide a detailed account of the effect of chronic ozone intraperitoneal injection on the deleterious effects of sleep deprivation on brain function in rats. Materials and Methods: Sleep deprivation was induced using the modified multiple platform model. The rats received REM sleep deprivation with an intraperitoneal injection of ozone or midazolam for 28 days. The effects of ozone on REM sleep deprivation-induced hippocampus-dependent learning and memory deficits were studied by the following approaches: Morris water maze (MWM) tests were used to evaluate spatial learning and memory of rats. Morphological changes in the brain were evaluated using hematoxylin and eosin (HE) staining. RNA-sequence was performed to seek a common mechanism. The expression of the targeted gene was examined by qPCR and Western blotting.Results:Ozone intraperitoneal injection reversed spatial learning and memory deficits associated with REM sleep deprivation, ameliorating pathological brain damage and down-regulating the hippocampal expression of Sema3A in rats after REM sleep deprivation. Conclusion:Ozone intraperitoneal injection alleviated sleep deprivation-induced spatial learning and memory deficits by protecting hippocampal neurons via down-regulation of the expression of Sema3A in the hippocampus.

Chronic caffeine consumption improves the acute sleep deprivation-induced spatial memory impairment while altering N-methyl-D-aspartate receptor subunit expression in male rats.

Caffeine is a psychostimulant substance that is mostly used to prevent fatigue, increase alertness, and ameliorate sleep loss situations. In this study, we aimed to investigate the effect of chronic caffeine consumption on learning and memory functions and related genes in rapid eye movement (REM) sleep-deprived rats. During the neonatal period (postnatal day [PND] 28) Wistar albino male rats (n = 32) were randomly assigned into four groups: Control (C), caffeine application (Cf), acute REM sleep-deprivation (RD), and caffeine application + acute RD (Cf + RD). The 48 h of RD was executed when caffeine administration was completed. The learning and memory performance was evaluated by the Morris water maze test (MWMT). Following this, the rats were decapitated to isolate hippocampus tissues. In MWMT, time spent in the targeted quadrant decreased significantly in the RD group compared with the C and Cf + RD group. NR2A expression level increased in the RD group compared with C, Cf, and Cf + RD groups (p < 0.05). NR2B expression level increased in RD and Cf + RD groups compared with C and Cf groups (p < 0.05). BDNF and c-Fos expression levels did not differ significantly between the groups. RD impaired hippocampal spatial memory performance in the MWMT test. Our results indicated that chronic caffeine consumption has a therapeutic effect on spatial memory deterioration impairment caused by RD. Furthermore, it seems that the effect of caffeine RD on the hippocampus may be mediated by NR2A.

Rapid Eye Movement Sleep Deprivation Enhances Adenosine Receptor Activation and the CREB1/YAP1/c-Myc Axis to Alleviate Depressive-like Behaviors in Rats.

As neuromodulators, adenosine and its receptors are mediators of sleep-wake regulation. A putative correlation between CREB1 and depression has been predicted in our bioinformatics analyses, and its expression was also predicted to be upregulated in response to sleep deprivation. Therefore, this study aims to elaborate the A1 and A2A adenosine receptors and CREB1-associated mechanism underlying the antidepressant effect of rapid eye movement sleep deprivation (REMSD) in rats with chronic unpredictable mild stress (CUMS)-induced depressive-like behaviors. The modeled rats were injected with adenosine A1 receptor antagonist DPCPX or adenosine A2A receptor antagonist ZM241385 to assess the role of adenosine receptors in depression. In addition, ectopic expression and depletion experiments of CREB1 and YAP1 were also conducted in vivo and in vitro. It was found that REMSD alleviated depressive-like behaviors in CUMS rats, as shown by increased spontaneous activity, sucrose consumption and percentage, and shortened escape latency and immobility duration. Meanwhile, A1 or A2A adenosine receptor antagonists negated the antidepressant effect of REMSD. REMSD enhanced adenosine receptor activation and promoted the phosphorylation of CREB1, thus increasing the expression of CREB1. In addition, the overexpression of CREB1 activated the YAP1/c-Myc axis and consequently alleviated depressive-like behaviors. Collectively, our results provide new mechanistic insights for an understanding of the antidepressant effect of REMSD, which is associated with the activation of adenosine receptors and the CREB1/YAP1/c-Myc axis.

0284 Repetitive Weekly REM Sleep Deprivation-Recovery Cycle Obtained from a Large U.S. Sample by Home-Based Under-Mattress Monitoring Devices

Abstract Introduction American adults are typically sleep deprived during weekdays and attempt to recover sleep on the weekends. Technological advances in home sleep monitoring have provided the opportunity to analyze sleep patterns on a scale much larger than previously imaginable. This study explores the weekly REM sleep deprivation–recovery cycle in a large U.S. sample. Methods Estimated total sleep time (TST) and REM/TST (R%) were analyzed by a commercially-available home-sleep-monitoring device (Sleeptracker-AI Monitor, Fullpower Technologies, California, USA). The device passively monitors sleep using piezo-electric sensors that register the forces exerted through the mattress. The de-identified data from the devices were analyzed following review and exemption of the study (#57681) from the Stanford University IRB. Data from 07/2020–06/2021, from 101,442 individuals with 14,277,964 recorded nights, were available. The analytic dataset included individuals with at least 300 nights of sleep per year and 26 of 52 nights per each day of the week (excluding nights abutting federal holidays). Results A total of 21,543 individuals (11,095 men, 51±14 years; 9,821 women, 50±15 years; 627 unspecified genders) and 6,850,717 recorded nights met the inclusion criteria. There is a stepwise increase in R% from Sunday night to Friday night and a decrease back to Sunday night, following a cycle of weekday sleep deprivation and weekend recovery. The means and standard deviations (across individuals’ averages) of TST in hours and R% for each night were: Sunday (TST*:7.21±0.885, R%*:24.20±3.09), Monday (TST*:7.18±0.853, R%*:24.56±3.10), Tuesday (TST*:7.16±0.847, R%*:24.67±3.13), Wednesday (TST*:7.16±0.845, R%*:24.80±3.15), Thursday (TST*:7.18±0.845, R%*:24.87±3.15), Friday (TST*:7.51±0.904, R%*:25.05±3.15), and Saturday (TST*:7.59±0.897, R%*:24.83±3.12). Each statistic, when compared with the previous night of the week, was significant (p &amp;lt; 0.05/7, Bonferroni corrected) by paired t-test (denoted by an asterisk). Conclusion The use of advanced technology to estimate sleep-wake patterns in a large sample permits the validation of a repetitive REM sleep deprivation–recovery cycle. Individuals are, on average, partially sleep deprived starting Sunday night, which leads to a progressive REM sleep rebound that transitions into a REM recovery cycle on Friday and Saturday nights. Further work will focus on studying this cycle within different groups (e.g., age, gender), across seasons, and including other sleep parameters. Support (If Any)

Sleep Disruption Exacerbates Cognitive Dysfunction by Promoting Lipid‐Immune Dysregulation in the Corticohippocampal System of Pentylenetetrazol‐Kindled Rats

Sleep deprivation has been identified as one of the triggers for seizures in patients with generalised epilepsy. Therefore, we tested whether rapid eye movement (REM) sleep deprivation would increase susceptibility to developing generalised seizures established by pentylenetetrazol (PTZ) kindling; and whether REM sleep deprivation would affect treatment response and cognitive outcomes in epileptic rats. Furthermore, possible mechanistic underpinnings such as lipid‐immune responses in the prefrontal cortex and hippocampus were evaluated. Male rats were either sleep‐deprived followed by PTZ kindling, or kindled before being sleep‐deprived, or kindled before sleep deprivation and treated with a known anticonvulsant, diazepam. Thereafter, cognitive behaviours were evaluated. Following euthanasia, the prefrontal cortex and hippocampus were extracted and processed for biochemical and histological/histochemical/immunohistochemical assessments. Our results showed increased susceptibility to epileptogenesis in the group exposed to sleep deprivation before kindling compared to the PTZ‐kindling group without sleep deprivation. Also, sleep deprivation aggravated epilepsy features in the sleep‐deprived PTZ‐kindled rats and negatively impacted drug (diazepam) response in these animals. These were all linked to a disruption in lipid profile, and interleukin‐17 (IL‐17) activity; exacerbation in demyelination, microglial activation, and low‐density lipoprotein receptor‐related protein 1 (LRP1) expression in the prefrontal cortex and hippocampus following sleep deprivation and PTZ kindling. Furthermore, we observed a substantial deterioration in spatial working memory especially in the sleep‐deprived PTZ‐kindled group compared to the kindled group. Overall, our findings suggest that impairment of cognitive functions as seen in the sleep deprivation before kindling and sleep deprivation after kindling groups is attributable to a perturbation in the interaction between lipoproteins, their receptors, immune cells and their inflammatory/phagocytic responses impairing myelination/remyelination, thus aggravating cognitive deficits.

Effects of citicoline administration on synaptic proteins in rapid eye movement sleep-deprived rats.

Objective(s):Sleep has a pivotal role in learning-memory and sleep deprivation (SD) negatively affects synaptic functioning. Cytidine-5-diphosphocholine (Citicoline) has been known to improve learning and memory functions. Our objective was to explore the effects of Citicoline on hippocampal and cortical synaptic proteins in rapid eye movement (REM) sleep-deprived rats.Materials and Methods:Rats (n=36) were randomly divided into 6 groups. Environmental control or sleep deprivation was done by placing the rat on a 13 cm diameter platform (Large Platform [LP] group) or on a 6.5 cm diameter platform (REMSD group), respectively, for 96 hours. Rats randomized for controls (Home Cage [HC] group) were followed up in home cages. Rats in each of the REMSD, LP or HC group were randomized to receive either saline (0,9%NaCl) or Citicoline (600 μmol/kg) intraperitoneally twice a day for four days. After the experiments, rats were sacrificed; their cerebral cortices and hippocampi were dissected for analyzing the levels of pre-synaptic proteins synaptophysin and synapsin I, and the post-synaptic density protein-95 (PSD-95) by Western-blotting. Results: Hippocampal levels of PSD-95, but not the pre-synaptic proteins, were reduced by REM sleep deprivation. Citicoline treatment ameliorated the reduction in PSD-95 levels in REM sleep-deprived rats. On the other hand, REM sleep deprivation was not found to be significantly effective on pre- or post-synaptic proteins in cerebral cortex.Conclusion:REM sleep deprivation reduces hippocampal PSD-95 levels which are enhanced by Citicoline treatment. These data propose that Citicoline may ameliorate the adverse effects of SD on hippocampal synaptic functioning.

Chaperone Hsp70 (HSPA1) Is Involved in the Molecular Mechanisms of Sleep Cycle Integration.

The molecular mechanisms of sleep cycle integration at the beginning and the end of the inactive period are not clear. Sleep cycles with a predominance of deep slow-wave sleep (SWS) seem to be associated with accelerated protein synthesis in the brain. The inducible Hsp70 chaperone corrects protein conformational changes and has protective properties. This research explores (1) whether the Hspa1 gene encoding Hsp70 protein activates during the daily rapid-eye-movement sleep (REMS) maximum, and (2) whether a lower daily deep SWS maximum affects the Hspa1 expression level during the subsequent REMS. Combining polysomnography in male Wistar rats, RT-qPCR, and Western blotting, we reveal a three-fold Hspa1 upregulation in the nucleus reticularis pontis oralis, which regulates REMS. Hspa1 expression increases during the daily REMS maximum, 5–7 h after the natural peak of deep SWS. Using short-term selective REMS deprivation, we demonstrate that REMS rebound after deprivation exceeds the natural daily maximum, but it is not accompanied by Hspa1 upregulation. The results suggest that a high proportion of deep SWS, usually observed after sleep onset, is a necessary condition for Hspa1 upregulation during subsequent REMS. The data obtained can inform the understanding of the molecular mechanisms integrating SWS and REMS and key biological function(s) of sleep.

Impact of Rapid Eye Movement Sleep Deprivation on Pain Behaviour and Oxidative Stress in the Thalamus: Role of Tualang Honey Supplementation.

BackgroundInsufficient sleep alters the body’s physiological functions. This study investigated whether oxidative stress (OS) in the thalamus was correlated with the pain behaviour score in the rapid eye movement (REM) sleep-deprived rat model.MethodsFour groups of Sprague-Dawley rats were included in the study (n = 6): i) control; ii) REM sleep-deprived rats for 72 h (REMsd); iii) REM sleep-deprived rats for 72 h pretreated with Tualang honey (REMsd-H) and iv) tank control (TC). Following the intervention, 1% formalin was injected on the right hind paw and pain behaviour was recorded for 1 h. OS markers of glutathione (GSH), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) in the thalamus were measured.ResultsREM sleep deprivation increased pain behaviour scores in phase II of the formalin test with decreased GSH, GR, SOD and CAT. The MDA level was significantly higher in the REMsd compared to REMsd-H. There was an inverse correlation between pain behaviour scores and GSH, GR and SOD levels. A positive correlation was found between the pain behaviour score and the MDA level.ConclusionOS levels were significantly correlated with the pain behaviour score in the REMsd rats. Tualang honey administration reduced pain behaviour score and OS in the thalamus.

Effect of rapid eye movement sleep deprivation during pregnancy on glucocorticoid receptor regulation of HPA axis function in female offspring

Poor maternal sleep quality during the different phases of pregnancy acts as a prenatal stress and is critical for fetal development. Despite the potential adverse effects of maternal stress on the behavior and physiology of the offspring, the mechanisms remain poorly understood. The present study investigates the effects of maternal sleep deprivation (SD) at different stages of pregnancy on the hypothalamic–pituitary–adrenal (HPA) axis in female offspring. The pregnant rats were subjected to sleep deprivation of 12 h per day at different stages; early (ESD), mid (MSD), and late (LSD) stages, on pregnancy days 1–7, 8–14, and 14–20, respectively. At postnatal day 60, levels of corticosterone (CORT), hypothalamic corticotropin-releasing factor receptor 1 (CRF-R1), and hippocampal glucocorticoid receptors (GR) were evaluated in the offspring. Although the hypothalamic CRF-R1 level was increased in the offspring of SD dams, immunohistochemical staining showed reduced immunoreactivity of GR in ESD and LSD offspring hippocampal area. Altogether, the data suggests that a critical period for adverse effects of SD on the HPA axis in female offspring of Wistar rats may be during early and late pregnancy.

REM Sleep Deprivation Alters Learning-Induced Cell Proliferation and Generation of Newborn Young Neurons in the Dentate Gyrus of the Dorsal Hippocampus.

The hippocampus-dependent "trace-appetitive conditioning task" increases cell proliferation and the generation of newborn young neurons. Evidence suggests that adult hippocampal neurogenesis and rapid eye movement (REM) sleep play an essential role in memory consolidation. On the other hand, REM sleep deprivation (REM-SD) induces detrimental effects on training-induced cell proliferation in the hippocampus's dentate gyrus (DG). Nonetheless, the role of REM sleep in the trace-appetitive memory and fate determination of the newly proliferated cells is not known. Here, we have studied the following: (I) the effects of 24 h of REM-SD (soon after training) on trace- and delay-appetitive memory and cell proliferation in the adult DG and (II) the effects of chronic (96 h) REM-SD (3 days after the training, the period in which newly generated cells progressed toward the neuronal lineage) on trace-appetitive memory and the generation of newborn young neurons. We used a modified multiple platform method for the selective REM-SD without altering non-REM (NREM) sleep. We found that 24 h of REM-SD, soon after trace-conditioning, impaired the trace-appetitive memory and the training-induced cell proliferation. Nevertheless, 96 h of REM-SD (3 days after the training) did not impair trace memory. Interestingly, 96 h of REM-SD altered the generation of newborn young neurons. These results suggest that REM sleep plays an essential role in training-induced cell proliferation and the fate determination of the newly generated cells toward the neuronal lineage.

REM sleep deprivation before extinction or reinstatement alters methamphetamine reward memory via D1-like dopamine receptors

We aimed to determine whether REM sleep deprivation (RSD) affects extinction and reinstatement of methamphetamine (METH) reward memory in male rats and also to evaluate the possible role of dopamine D1-like and D2-like dopamine (DA) receptors in these processes. Male rats were trained to acquire METH-induced place preference (2 mg/kg, i.p.). METH reward memory was then reinstated following a 10-day extinction period. The animals underwent a 72-hour sleep deprivation episode by multiple platforms method (in separate groups), either before the extraction or before the reinstatement of METH reward memory. The animals received SCH 23390 (0.01 or 0.05 mg/kg, i.p.) or sulpiride (20 or 60 mg/kg, i.p.) as antagonists of D1-like and D2-like DA receptors, respectively, either immediately following each daily extinction session or before the reinstatement of METH-seeking behavior. The RSD episode postponed extinction and facilitated reinstatement of METH reward memory. Administration of SCH 23390, but not sulpiride, facilitated METH extinction and decreased reinstatement of the extinguished METH-seeking behavior. Moreover, locomotor activity was not affected by METH and/or the RSD paradigm. The results would seem to suggest that the D1-like, but not the D2-like, DA receptors may be involved in the extinction and reinstatement of the extinguished METH reward memory in RSD animals. Nonetheless, more investigations are needed to elucidate the exact mechanisms involved.

REM-Sleep Deprivation Induces Mitochondrial Biogenesis in the Rat Hippocampus

Sleep loss is proposed as a trigger for manic episodes in bipolar disorder in humans. It has been shown that sleep and wakefulness can affect changes in mitochondrial gene expression, oxidative phosphorylation (OXPHOS) activity, and morphology in the brain. In this study, we investigated alterations in mitochondrial bioenergetic function in the brain of rats after 72-h rapid eye movement sleep deprivation (REM-SD). Alterations in the mitochondrial DNA (mtDNA) copy number were detected in the prefrontal cortex and hippocampus through amplification of mitochondrially encoded NADH dehydrogenase 1 (mt-Nd1) gene using quantitative real-time polymerase chain reaction. The expression levels of mitochondrial biogenesis-related proteins such as peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PPARGC1A), cytochrome c oxidase subunit 4I1 (COX4I1) and sirtuin 3 (SIRT3) were assessed using western blot analysis and immunohistochemistry. We found that REM-SD significantly increased the mtDNA copy number in the hippocampus but not in the prefrontal cortex. In addition, REM-SD increased the protein expression of COX4I1 in the hippocampus. Furthermore, we observed manic-like behaviors in rats exposed to 72-h REM-SD. REM-SD increased locomotion in the open-field test and the time spent in open arms in the elevated plus-maze test. REM-SD may induce mitochondrial dysfunction in the brain, which may be involved in the induction of mania.

Effect of selective sleep deprivation on heart rate variability in post-90s healthy volunteers.

The 5-minute frequency domain method was used to examine the effects of polysomnography (PSG)-guided acute selective sleep deprivation (REM/SWS) on the cardiovascular autonomic nervous system, heart rate, and rhythm in healthy volunteers to understand the relationship between cardiac neuro regulatory homeostasis and cardiovascular system diseases in healthy subjects. The study included 30 healthy volunteers selected through the randomized-controlled method, randomly divided into REM sleep deprivation and SWS sleep deprivation groups. PSG analyses and dynamic electrocardiogram monitoring were done at night, during slow wave sleep or REM sleep. An all-night sleep paradigm, without any interruptions, was tested 3 times for comparison. The frequency domain parameter method was further used to monitor the volunteers 5 min before and after a period of sleep deprivation. According to the characteristics of the all-night sleep scatter plot, healthy volunteers were divided into abnormal and normal scatter plot groups. When compared with the period before sleep deprivation, high frequency (HF) and normalized high-frequency component (HFnu) were found to be decreased. Normalized low-frequency component (LFnu) increased in the abnormal scatter plot group after sleep deprivation, and this difference was statistically significant (P < 0.05). The scatter plot also showed that very low frequency (VLF) increased only in the normal group after deprivation and this difference, as well, was statistically significant (P < 0.05). The increase in diastolic blood pressure in the abnormal group was statistically significant (P < 0.05), but the change in blood pressure in the normal group was not statistically significant (P > 0.05). There are 62.5% of the patients and 20% of the employees that were observed to have abnormal whole-night sleep patterns during the uninterrupted whole-night sleep regime. Patients with atrial or ventricular premature beats (more than 0.1%), and those with ST-t changes during sleep, were all ascertained as abnormal. We concluded that some healthy people could face unstable autonomic nervous functioning related to their long-term tension, anxiety, time urgency, hostility, and other chronic stress states. In the face of acute sleep deprivation selectivity, mild stress based excitability of the vagus nerve is reduced, which diminishes the protective function, making them susceptible to conditions such as premature ventricular arrhythmia.

TUALANG HONEY MODULATED NOCICEPTIVE RESPONSES IN THE THALAMUS OF REM SLEEP DEPRIVATION RAT MODEL

Sleep deprivation has been shown to alter pain responses in humans and animals. The present study investigated whether the administration of Tualang honey in the rapid eye movement (REM) sleep deprivation rat model would modulate nociceptive responses with associated changes in the thalamus. Forty-eight Sprague Dawley male rats were randomised into four groups (n=12 for each group): control group (FMC), REM sleep deprivation (REMsd), REM sleep deprivation pretreated with Tualang Honey for 1 month (REMsdH) and tank control (TC). Following sleep deprivation for 72 hours, a formalin test was conducted and pain behaviour was recorded and analysed. The rats were sacrificed, and the brains were removed for histological examination and assessment of N-methyl-D-aspartate receptor (NMDA R2) level in the thalamus. REMsdH group showed a significantly lower level of pain behaviour score and NMDA R2 compared to the REMsd group (p&lt;0.05). In addition, REMsdH also demonstrated a significantly higher number of Nissl stained neurons in comparison with the REMsd group (p&lt;0.05). Furthermore, dark neurons, suggestive of neuronal damage, were observed in the REMsd group. In conclusion, administration of Tualang honey before REM sleep deprivation modulated nociceptive responses and prevent changes in thalamic neurons and NMDA R2 level.