Recovery Sleep Research Articles

Balancing brain metabolic states during sickness and recovery sleep.

Sickness sleep and rebound following sleep deprivation share humoral signals including the rise of cytokines, in particular interleukins. Nevertheless, they represent unique physiological states with unique brain firing patterns and involvement of specific circuitry. Here, we performed untargeted metabolomics of mouse cortex and hippocampus to uncover changes with sickness and rebound sleep as compared with normal daily sleep. We found that the three settings are biochemically unique with larger differences in the cortex than in the hippocampus. Both sickness and rebound sleep shared an increase in tryptophan. Surprisingly, these two sleep conditions showed opposite modulation of the methionine-homocysteine cycle and differences in terms of the energetic signature, with sickness impinging on glycolysis intermediates whilst rebound increased the triphosphorylated form of nucleotides. These findings indicate that rebound following sleep deprivation stimulates an energy rich setting in the brain that is devoid during sickness sleep.

Individualized rTMS Intervention Targeting Sleep Deprivation-Induced Vigilance Decline: Task fMRI-Guided Approach.

Sleep deprivation (SD) is prevalent in our increasingly round-the-clock society. Optimal countermeasures such as ample recovery sleep are often unfeasible, and brief naps, while helpful, do not fully restore cognitive performance following SD. Thus, we propose that targeted interventions, such as repetitive transcranial magnetic stimulation (rTMS), may enhance cognitive performance recovery post-SD. We recruited 50 participants for two SD experiments. In the first experiment, participants performed a psychomotor vigilance task (PVT) under three conditions: normal sleep (resting wakefulness), after 24 h of SD, and following a subsequent 30-min nap. We analyzed dynamic changes in PVT outcomes and cerebral responses across conditions to identify the optimal stimulation target. Experiment 2 adopted the same protocol except that, after the nap, 10-Hz, sham-controlled, individualized rTMS was administrated. Then, an analysis of variance was conducted to investigate the ability of stimulation to improve the PVT reaction times. Through task-related functional magnetic resonance imaging, we identified cerebral responses within the right middle frontal gyrus (MFG) as the optimal stimulation target. Subsequent application of individualized 10-Hz rTMS over the right MFG attenuated SD-induced deterioration of vigilance. Our findings suggest that combining a brief nap with individualized rTMS can significantly aid the recovery of vigilance following SD. This approach, through modulating neural activity within functional brain networks, is a promising strategy to counteract the cognitive effects of SD.

Sex differences in sleep deficits in mice with an autism-linked Shank3 mutation

BackgroundInsomnia is more prevalent in individuals with Autism Spectrum Disorder (ASD), can worsen core-symptoms and reduces quality of life of both individuals and caregivers. Although ASD is four times more prevalent in males than females, less is known about sex specific sleep differences in autistic individuals. Recent ASD studies suggest that sleep problems may be more severe in females, which aligns with the sex bias seen in insomnia for the general population. We have previously shown that male mice with a mutation in the high confidence ASD gene Shank3, Shank3∆C, recapitulate most aspects of the ASD insomnia phenotype. The objective of the present study was to leverage the Shank3∆C model to investigate sex-specific effects in sleep using polysomnography.MethodsAdult male and female Shank3∆C and wildtype (WT) littermates were first recorded for 24 h of baseline recordings. Subsequently, they were sleep deprived (SD) for five hours via gentle handling and allowed 19 h of recovery sleep to characterize the homeostatic response to SD. Vigilance states (rapid eye movement (REM) sleep, non-rapid eye movement (NREM) sleep and wake) were assigned by manual inspection using SleepSign. Data processing, statistical analysis and visualization were conducted using MATLAB.ResultsSex and genotype effects were found during baseline sleep and after SD. At baseline, male Shank3∆C mice sleep less during the dark period (active phase) while female Shank3∆C mice sleep less during the light period (rest phase) and sleep more during the dark period. Both male and female Shank3∆C mice show reduced spectral power in NREM sleep. We detect a significant effect of sex and genotype in sleep onset latency and homeostatic sleep pressure (sleepiness). In addition, while male Shank3∆C mice fail to increase sleep time following SD as seen in WT, female Shank3∆C mice decrease sleep time.ConclusionsOverall, our study demonstrates sex differences in sleep architecture and homeostatic response to SD in adult Shank3∆C mice. Thus, our study demonstrates an interaction between sex and genotype in Shank3∆C mice and supports the use of the Shank3∆C model to better understand mechanisms contributing to the sex differences in insomnia in ASD in clinical populations.

Association of weekday-to-weekend sleep duration pattern with myocardial infarction: analysis of the NHANES 2017- 2020

Abstract Background Short sleep is linked to increased acute myocardial infarction (MI) risk.However, the association of weekend-to-weekday sleep patterns with MI in a nationally representative population remains unknown. The goal is to investigate how weekday and weekend sleep durations affect myocardial infarction (MI) in the general population, and if longer weekend sleep can offset insufficient weekday sleep's effects. Methods A cross-sectional study utilized data from the 2017-2020 NHANES to examine the relationship between sleep patterns and MI. Participants self-reported their average sleep durations on weekdays (1) and weekends (2), along with the calculated weekend-to-weekday sleep duration ratio (SDR) (3). Logistic regression models, adjusting for various factors, including demographics and comorbidities, were employed to analyze the association. Those with SDR > 1 had more weekend sleep, while an SDR = 1 indicated equal sleep durations. Results The study involved 9,205 adult participants, with a mean ± SD age of 68.8 ± 10.8 years and 30.7% being female. Among them, 4.65% (428 patients) had a history of MI. The mean ± SD of weekday and weekend sleep hours was 7.6 ± 1.7 and 8.3 ± 1.8 hours, respectively. For weekday sleep duration, after univariate analysis, individuals compared to those in Q1 were statistically significant 0.72 times less likely in Q2 and 1.4 times more likely in Q4 to experience MI . While MI was 0.76 times less likely to occur among participants in Q3, it was not statistically significant (95% CI Q2: 0.54, 0.96; Q4: 1.05, 1.76; Q3:0.57, 1.00). After adjusting, participants only in Q3 were statistically significant 0.71 times less likely to develop MI.(Q3: 95% CI 0.51, 0.99). For weekend sleep duration, the univariate analysis showed that individuals in Q2, Q3, and Q4 were significantly less likely to experience MI (OR = 0.63, 0.67, and 0.69; 95% CIs: 0.48-0.82, 0.51-0.87, 0.53-0.90, respectively) After adjusting, only participants in Q2 were statistically significant less likely to develop MI (OR = 0.71; 95% CI 0.52 - 0.96). For the weekend-to-weekday sleep duration ratio (SDR), after univariate analysis, individuals were statistically significant 0.54 times less likely, and 1.5 times more likely to experience MI in those whose SDR is more than 1, and those whose SDR equals 1, respectively (95% CI SDR > 1: 1.14, 1.98; SDR = 1: 0.39, 0.72). After adjusting, participants with SDR more than 1 were statistically significant 0.69 times less likely to develop MI. Conclusions Moderate sleep durations on weekdays (in Q3), weekends (in Q2), along with SDR more than 1, were negatively linked with MI in a general population. This implies that sleep durations on both weekends and weekdays have comparable associations with MI. Additionally, full recovery sleep on weekends following sleep-deprived weekdays, might reduce MI risk. Further studies are needed to explore impact of weekend and weekday sleep patterns on MI.Histogram and Margins plotTable of Odd ratios

Fasting as an intervention to alter the impact of simulated night-shift work on glucose metabolism in healthy adults: a cluster randomised controlled trial.

Night-shift work causes circadian misalignment and impairs glucose metabolism. We hypothesise that food intake during night shifts may contribute to this phenomenon. This open-label, multi-arm, single-site, parallel-group controlled trial involved a 6 day stay at the University of South Australia's sleep laboratory (Adelaide, SA, Australia). Healthy, non-shift-working adults without obesity (N=55; age 24.5 ± 4.8 years; BMI 24.8 ± 2.8 kg/m2) were assigned to the next available run date and cluster randomised (1:1:1) to fasting-at-night (N=20), snack-at-night (N=17), or meal-at-night (N=18) conditions. One participant withdrew from each group, prior to starting the study. Due to study design, neither participants nor people collecting their measurements could be blinded. Statistical and laboratory staff were concealed to study allocation. Participants were fed at calculated energy balance, with the macronutrient composition of meals being similar across conditions. The primary outcomes were a linear mixed-effects model of glucose, insulin and NEFA AUC in response to a 75 g OGTT that was conducted prior to and after 4 consecutive nights of shift work plus 1 night of recovery sleep. Insulin sensitivity, insulinogenic and disposition indexes were also calculated. Night-shift work impaired insulin sensitivity, as measured by insulin AUC (p=0.035) and the insulin sensitivity index (p=0.016) across all conditions. Insulin secretion, as measured by the insulinogenic index, was increased in the fasting-at-night condition only (p=0.030), resulting in a day×condition interaction in glucose AUC (p<0.001) such that glucose tolerance was impaired in the meal-at night (+2.00 [95% CI 1.45, 2.56], p<0.001) and snack at-night (+0.96 [0.36, 1.56], p=0.022) conditions vs the fasting-at-night (+0.34 [-0.21, 0.89]) condition. A day×condition interaction was also observed in NEFA AUC (p<0.001), being higher in the meal-at-night (+0.07 [0.03, 0.10]. p=0.001) and snack-at-night (0.01 [-0.03, 0.05], p=0.045) conditions vs the fasting-at-night condition (-0.02 [-0.06, 0.01]). No adverse events occurred. The timing of food intake has a critical effect on glucose metabolism during simulated night-shift work, which was readily amendable to a meal re-timing intervention. Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12616001556437 FUNDING: This work was funded by the National Health and Medical Research Council (NHMRC), APP1099077.

Caffeine Intake Alters Recovery Sleep after Sleep Deprivation.

Caffeine is a well-known psychostimulant reputed to alleviate the deleterious effects of sleep deprivation. Nevertheless, caffeine can alter sleep duration and quality, particularly during recovery sleep. We evaluated the effects of acute caffeine intake on the duration and quality of recovery sleep following total sleep deprivation (TSD), taking into account daily caffeine consumption. Forty-one participants performed a double-blind, crossover TSD protocol (38 h of continuous wakefulness) with acute caffeine or placebo. Caffeine (2.5 mg/kg) or placebo was administered twice during continuous wakefulness (last treatment 6.5 h before bedtime for the recovery night). Polysomnographic measurements were recorded using a connected headband. TSD was associated with a rebound in total sleep time (TST) on the recovery night (+110.2 ± 23.2 min, p < 0.001). Caffeine intake decreased this recovery TST (-30.2 ± 8.2 min p = 0.02) and the N3 sleep stage duration (-35.6 ± 23.2 min, p < 0.01). Caffeine intake altered recovery sleep continuity (increased number of long awakenings), stability (higher stage transition frequency), and organization (less time spent in complete sleep cycle) and decreased the delta power spectral density during NREM sleep. On the recovery night, habitual daily caffeine consumption was negatively correlated with TST in caffeine and placebo conditions and positively correlated with wake after sleep onset (WASO) duration and with the frequency of long (>2 min) awakenings in the caffeine condition only. Acute caffeine intake during TSD affects nighttime recovery sleep, with an interaction with daily consumption. These results may influence advice on caffeine intake for night-shift workers. (NCT03859882).

Enhanced homeostatic sleep response and decreased neurodegenerative proteins in cereblon knock-out mice

Energy homeostasis and sleep have a bidirectional relationship. Cereblon (CRBN) regulates energy levels by ubiquitinating the AMP-activated protein kinase(AMPK), an energy sensor. However, whether CRBN participates in sleep is unclear. Here, we examine sleep–wake patterns in Crbn+/+ and Crbn−/− mice during 24-h baseline, 6-h sleep deprivation (SD), and following 6-h recovery sleep (RS). At baseline, overall sleep patterns are similar between genotypes. However, SD decreases CRBN expression in Crbn+/+ mice and increases phospho-Tau, phospho-α-synuclein, DNAJA1 (DJ2), and DNAJB1 (DJ1) in both genotypes, with Crbn−/− mice showing a lesser extent of increase in p-Tau and p-α-synuclein and a higher level of heat shock protein 70 (HSP70), DJ2, and DJ1. During RS, Crbn−/− mice show increased slow-wave activity in the low-delta range (0.5–2.5 Hz), suggesting higher homeostatic sleep propensity associated with AMPK hyperactivation. By illuminating the role of CRBN in regulating sleep–wake behaviors through AMPK, we suggest CRBN as a potential therapeutic target for managing sleep disorders and preventing neurodegeneration.

Monosodium glutamate disrupts zebrafish sleep-like state likely through activation of peripheral nervous system glutamate receptors

Monosodium glutamate (MSG), a widely used flavor enhancer, has raised concerns about its effects on behavior and sleep. This study investigates how MSG influences zebrafish sleep-like state (SLS) and interacts with other substances affecting neurobehavioral responses. Adult zebrafish were exposed to MSG at concentrations of 50, 100, and 150 mg/L, and their swimming speeds and SLS durations were recorded over a 14-hour night period. The results indicated that higher MSG concentrations increased swimming speeds and decreased SLS duration, suggesting heightened excitability and reduced sleep recovery. The study further evaluated how MSG impacts anesthesia sensitivity induced by 2-phenoxyethanol (POE) compared to alcohol and nicotine. Zebrafish were pre-treated with 50 mg/L MSG, 0.5% alcohol, or 0.5 mg/L nicotine before being anesthetized with POE. Nicotine decreased anesthesia sensitivity in a concentration-dependent manner by enhancing neurotransmitter release. In contrast, MSG and alcohol had minimal effects on anesthesia. The limited impact of MSG on anesthesia sensitivity suggests that MSG primarily affects peripheral nervous system functions rather than central nervous system functions, likely due to its poor ability to cross the blood-brain barrier. Overall, the findings demonstrate that MSG disrupts zebrafish behavior through peripheral mechanisms, affecting both swimming activity and sleep patterns. Nicotine, on the other hand, influences behavior through central nervous system interactions. These results highlight the need for further research to better understand how dietary additives like MSG impact neurobehavioral functions in aquatic models, offering insights into their broader implications for sleep and behavior.

An Update of the Promise of Glycine Supplementation for Enhancing Physical Performance and Recovery.

Glycine, the simple amino acid, is a key component of muscle metabolism with proven cytoprotective effects and hypothetical benefits as a therapeutic nutrient. Cell, in vitro, and animal studies suggest that glycine enhances protection against muscle wasting by activating anabolic pathways and inhibiting proteolytic gene expression. Some evidence indicates that glycine supplementation may enhance peak power output, reduce lactic acid accumulation during high-intensity exercise, and improve sleep quality and recovery. This literature review critically explores glycine's potential as an ergogenic aid and its relevance to muscle regeneration, muscle strength, endurance exercise performance, and sleep quality. It also underscores key areas for future research. It is concluded that more randomized controlled clinical trials in humans are needed to confirm glycine's potential as a dietary supplement to support muscle function, recovery, and overall athletic performance as an ergogenic aid and to establish nutritional recommendations for athletic performance. Also, it is essential to consider that high doses (>500 mg/kg of body mass) could induce cytotoxic effects and contribute to acute glutamate toxicity.

Microglial morphology aligns with vigilance stage‐specific neuronal oscillations in a brain region‐dependent manner

AbstractMicroglia, the resident immune cells in the brain, dynamically adapt their morphology based on their functional state. This study explored the relationship between microglial morphology and sleep–wake cycles in mice. Using Iba1 immunostaining to identify microglia, we quantified morphological changes in microglia at different timepoints in multiple brain regions (cortex, hippocampus, basal forebrain, hindbrain, and cerebellum) in B6 male mice using semi‐automated 3D structural analysis. Simultaneously, in a separate group, we monitored wake and sleep stage‐specific brain activity using EEG/EMG recordings. During natural sleep–wake cycles, we observed increased microglial complexity (enlarged volume, territorial coverage, and ramification) during wakefulness, characterized by high‐frequency theta (8–12 Hz) and gamma activity (30–80 Hz). Conversely, during NREM sleep, which is dominated by delta activity (0.5–4 Hz), microglia displayed reduced complexity. Notably, this pattern was absent in brain regions lacking direct functional connections to areas generating vigilance stage‐dependent thalamocortical oscillations. We then extended wakefulness to decouple circadian influence from sleep–wake‐specific neuronal activity. This procedure attenuated the decrease in microglial complexity observed during natural sleep, suggesting a crucial role for neuronal activity. Subsequent recovery sleep restored microglial features, independent of the time of day (zeitgeber time). These findings reveal a dynamic interplay between vigilance stage‐specific thalamocortical activity and microglial morphology across various brain regions. This suggests a potential role for microglia in sleep regulation and warrants further investigation to understand the underlying mechanisms.

Daily within-fluctuations in need frustration and implications for employee recovery and well-being: A mixed-methods study.

Daily variations in frustration of basic psychological needs (autonomy, competence, and relatedness) have received limited attention. This mixed-methods study examines such daily variations and their relations to recovery from work and employee well-being. The study uses multilevel modeling of repeated measures through daily surveys from a period of 8 working days across 2 consecutive weeks, combined with in-depth interviews. A sample of 54 Norwegian health-care workers completed a total of 242 daily surveys, and follow-up interviews were conducted with 10 participants. Quantitative results showed that need frustration at work fluctuates from day to day, with competence frustration notably impairing recovery (i.e., lower psychological detachment and relaxation) and increasing ill-being (i.e., higher exhaustion and negative work affect). Autonomy frustration was related to increased exhaustion and sleep complaints, while relatedness frustration showed no significant relation to recovery, ill-being, or sleep. Qualitative findings corroborated and expanded on these results, offering deepened insights into how competence and, sometimes, relatedness need frustration hampered the recovery process and sleep. The results of the current study add to the scarce body of literature on daily fluctuations in need frustration at work and its adverse consequences.

Effect of Head and Neck Massage on Sleep and Fatigue Recovery in Elderly Women

Effect of Head and Neck Massage on Sleep and Fatigue Recovery in Elderly Women

Five percent CO2 inhalation alleviates hippocampal glutamate and water homeostasis disturbance, neuronal damage, and learning‐memory impairment in sleep‐deprived rats

AbstractBackgroundSleep deprivation causes hippocampal injury, manifesting as neuronal damage and learning‐memory impairment. These negative effects may be associated with disturbance of hippocampal glutamate and water homeostasis, which induces excessive neuronal excitability. Five percent CO2 inhalation has been shown to suppress neuronal excitability. Here, we aimed to investigate whether 5% CO2 inhalation facilitates the recovery of hippocampal glutamate and water homeostasis, neuron morphology, and learning‐memory ability in sleep‐deprived rats.MethodsThirty‐six Sprague‐Dawley female rats were randomly divided into three groups including normal sleep (Group 1, NS, n = 12), sleep deprivation followed by sleep recovery (Group 2, SD+SR, n = 12), sleep deprivation followed by sleep recovery and 5% CO2 inhalation (Group 3, SD+SR+CO2, n = 12) by random number table. Each group was divided into two subgroups (n = 6 each subgroup) for different experiments randomly by random number table.ResultsWe found that 5% CO2 inhalation facilitated the recovery of hippocampal glutamate concentration (7.549 ± 0.310, 8.716 ± 0.463, and 7.493 ± 0.281 mmol/L at Days 1, 3, and 5 in Group 3, F2, 15 = 22.06, p &lt; 0.0001) and hippocampal apparent diffusion coefficient mean value (8.210 ± 0.274, 7.685 ± 0.171, 8.265 ± 0.269 at Days 1, 3, and 5 in Group 3, F2, 15 = 10.45, p = 0.0014), enhanced expression level of astrocyte‐specific membrane protein glutamate transporter‐1, promoted the polarized distribution of aquaporin 4, reduced hippocampal neuronal damage and improved learning‐memory ability in sleep‐deprived rats.ConclusionThis study showed that 5% CO2 inhalation can serve as a novel strategy for alleviating sleep deprivation‐induced hippocampal injury.

Transcriptional dynamics of sleep deprivation and subsequent recovery sleep in the male mouse cortex.

Sleep is an essential, tightly regulated biological function. Sleep is also a homeostatic process, with the need to sleep increasing as a function of being awake. Acute sleep deprivation (SD) increases sleep need, and subsequent recovery sleep (RS) discharges it. SD is known to alter brain gene expression in rodents, but it remains unclear which changes are linked to sleep homeostasis, SD-related impairments, or non-sleep-specific effects. To investigate this question, we analyzed RNA-seq data from adult wild-type male mice subjected to 3 and 5-6 hours of SD and 2 and 6 hours of RS after SD. We hypothesized molecular changes associated with sleep homeostasis mirror sleep pressure dynamics as defined by brain electrical activity, peaking at 5-6 hours of SD, and are no longer differentially expressed after 2 hours of RS. We report 5-6 hours of SD produces the largest effect on gene expression, affecting approximately half of the cortical transcriptome, with most differentially expressed genes (DEGs) downregulated. The majority of DEGs normalize after 2 hours of RS and are involved in redox metabolism, chromatin regulation, and DNA damage/repair. Additionally, RS affects gene expression related to mitochondrial metabolism and Wnt-signaling, potentially contributing to its restorative effects. DEGs associated with cholesterol metabolism and stress response do not normalize within 6 hours and may be non-sleep-specific. Finally, DEGs involved in insulin signaling, MAPK signaling, and RNA-binding may mediate the impairing effects of SD. Overall, our results offer insight into the molecular mechanisms underlying sleep homeostasis and the broader effects of SD.

Subjective sleep may mediate the associations between tomorrow anticipations and next-day affect.

This study investigated whether stress and positive anticipations about tomorrow are associated with emotional experiences the following day, mediated by the preceding night's sleep. Data were from 141 full-time nurses, utilizing a 14-day ecological momentary assessment combined with actigraphy sleep monitoring. Each evening, participants rated the anticipated pleasantness or stressfulness of the following day. Each morning, participants reported on their previous night's sleep. Additionally, participants reported their momentary positive affect (PA) and negative affect (NA) three times per day, with daily averages computed. Multilevel mediation models, adjusted for sociodemographics, work shift, workday, and previous day's affect, revealed that days following more stress anticipations were associated with reduced PA and increased NA. Conversely, days following more pleasantness anticipations were associated with increased PA and decreased NA. These within-person associations were mediated by self-reported time-in-bed, sufficiency, and quality, such that less stressful and more pleasant anticipations were associated with better sleep, and better sleep was subsequently associated with increased PA and decreased NA. No mediation was found by the actigraphy sleep parameters. Findings suggest that emotional states may covary not only with present stimuli but also with anticipation of future events and subjective sleep recovery in the context of those anticipations.

Chronic sleep restriction during juvenility alters hedonic and anxiety-like behaviours in a sex-dependent fashion in adolescent Wistar rats.

Chronic reduction of sleep time in children and adolescents has been related to increased incidence of anxiety and depression. In rats, protocols of protracted sleep deprivation or chronic sleep restriction (CSR) are considered a stressor. In previous studies we showed that post-weaning CSR in male rats induces anxiety-like behaviour and changes in neurotransmission in emotion-related brain areas. In the present study we examined whether the effects of this adversity are sex-dependent. Twenty-two litters, containing four males and four females were distributed into control (CTL) and CSR groups. CSR began on postnatal day (PND) 21 and lasted for 21 days; each day the animals were placed onto small platforms immersed in water for 18 h and were allowed to sleep freely in their home-cages for the remaining 6 h. Throughout the CSR, all animals underwent the sucrose splash test once/week to assess their self-care and hedonic behaviours. Body weight was measured on PNDs 21 and 42. At the end of CSR period, the adolescents were allowed to sleep freely for 2 days, after which, behavioural tests began. Within each litter, one male and one female (pair) were not tested and provided blood and brain for determination of basal corticosterone (CORT) levels and hippocampal BDNF. One pair was tested in the sucrose preference test (SPT), one pair on the elevated plus maze (EPM) and one pair in the forced swim test (FST). CORT was measured after all conditions. CSR impaired self-care behaviour and body weight gain in males and females and increased relative adrenal weight only in males. There were no changes in sucrose intake in the SPT; CSR females displayed less immobility in the FST and CSR males displayed more anxiety-like behaviour in the EPM. CORT levels were similar between CTL and CSR males, whilst lower in CSR females than CTL ones in all experimental conditions. No changes in BDNF levels were detected in the dorsal hippocampus of CSR rats. The results indicate that CSR impaired self-care behaviour in both sexes, but only males displayed anxiety-like behaviour, whilst sleep recovery in females appeared to normalise their behaviour.

Impact of chronic sleep deprivation on male reproductive health: Insights from testicular and epididymal responses in mice.

Sleep deprivation (SD) can cause damage to the male reproductive system. However, the duration required for such damage and the specific sequence and severity of damage to the testis and epididymis remain unclear. To investigate the effects of different durations of SD on different parts of the testis and epididymis caput, corpus, and cauda. Adult ICR mice were randomly assigned to five groups: the SD group (SD for 18h/day for 1, 2, 3, or 4weeks), the SD + Vit E group (supplemented with Vit E 50mg/kg/d during 4weeks of SD, the SD+NS group (saline supplementation during 4weeks of SD), the SD + RS group (5weeks of recovery sleep after 4weeks of SD), and a normal sleep control (Ctrl) group. Following the interventions, sperm parameters, testicular and epididymal histopathology, inflammatory response, and oxidative stress markers were compared between the groups. Compared to the Ctrl group, the SD group showed a decrease in sperm motility and concentration from SD 2W and SD 3W, respectively. Decreases in sperm concentration and motility were more pronounced in the cauda compared to the caput and corpus. Pathological damage was less severe in the epididymis caput than in the corpus and cauda. After 4weeks of SD, inflammation and oxidative stress increased in both testes and epididymis. Both sleep recovery and vitamin E supplementation showed significant improvements, though they did not fully reach the level of the Ctrl group. Chronic SD for more than 2weeks causes varying degrees of damage to the testis, epididymis caput, corpus, and cauda in male mice. This damage is not fully reversible after 5weeks of sleep recovery and antioxidant stress treatment. These findings help us to identify and prevent SD damage to the male reproduction at an early stage.

Sleep deprivation and recovery: Endurance racing as a novel model.

The aim of this study was to investigate sleep-wake behavior and gain insights into perceived impairment (sleep, fatigue, and cognitive function) of athletes competing in two international multi-day adventure races. Twenty-four athletes took part across two independent adventure races: Queensland, Australia and Alaska, USA. Individual sleep periods were determined via actigraphy, and racers self-reported their perceived sleep disturbances, sleep impairment, fatigue and cognitive function. Each of these indices was calculated for pre-, during- and post-race periods. Sleep was severely restricted during the race period compared to pre-race (Queensland, 7:46 [0:29] vs. 2:50 [1:01]; Alaska, 7:39 [0:58] vs. 2:45 [2:05]; mean [SD], hh:mm). As a result, there was a large cumulative sleep debt at race completion, which was not 'reversed' in the post-race period (up to 1week). The deterioration in all four self-reported scales of perceived impairment during the race period was largely restored in the post-race period. This is the first study to document objective sleep-wake behaviors and subjective impairment of adventure racers, in the context of two geographically diverse, multi-day, international adventure races. Measures of sleep deprivation indicate that sleep debt was extreme and did not recover to pre-race levels within 1week following each race. Despite this objective debt continuing, perceived impairment returned to pre-race levels quickly post-race. Therefore, further examination of actual and perceived sleep recovery is warranted. Adventure racing presents a unique scenario to examine sleep, performance and recovery.

Relationship between Workload, Psychological State and Recovery in Female Soccer Athletes.

This study assessed the multifaceted relations between measures of workload, psychological state, and recovery throughout an entire soccer season in female collegiate soccer athletes (19.8±1.2 yrs, 132±12.3 lbs, 63±3.2 in). A prospective longitudinal study was utilized to measure workload (GPS training load, Rate of Perceived Exertion (RPE), psychological state (mental stress, mental fatigue, and mood), and recovery (sleep duration, sleep quality, and soreness), during 90 observations (59 training sessions and 21 games). Separate linear-mixed effect models were used to assess outcomes of RPE, soreness, and sleep duration. A linear mixed-effects model explained 59% of the variance in RPE following each session. Specifically, each standard deviation increase in GPS load and mental stress in the morning prior to training increased RPE by 1.46 (SE=0.08) and 0.29 (SE=0.07), respectively, following that day's training. Furthermore, a significant interaction was found between several predictor variables and chronological day in the season while predicting RPE. Specifically, for each standard deviation increase in GPS load, RPE went up by 0.0055 per day during the season suggesting that load had a higher impact on RPE as the season progressed. In contrast, the interaction of day by mental stress, sleep duration, and soreness continued to be stronger as the season progressed. Each linear mixed-effect model predicted a larger amount of variance when accounting for individual variations in the random effects.

Effects of low-dose acetylsalicylic acid on the inflammatory response to experimental sleep restriction in healthy humans

BackgroundSleep deficiencies, such as manifested in short sleep duration or insomnia symptoms, are known to increase the risk for multiple disease conditions involving immunopathology. Inflammation is hypothesized to be a mechanism through which deficient sleep acts as a risk factor for these conditions. Thus, one potential way to mitigate negative health consequences associated with deficient sleep is to target inflammation. Few interventional sleep studies investigated whether improving sleep affects inflammatory processes, but results suggest that complementary approaches may be necessary to target inflammation associated with sleep deficiencies. We investigated whether targeting inflammation through low-dose acetylsalicylic acid (ASA, i.e., aspirin) is able to blunt the inflammatory response to experimental sleep restriction. Methods46 healthy participants (19F/27M, age range 19–63 years) were studied in a double-blind randomized placebo-controlled crossover trial with three protocols each consisting of a 14-day at-home monitoring phase followed by an 11-day (10-night) in-laboratory stay (sleep restriction/ASA, sleep restriction/placebo, control sleep/placebo). In the sleep restriction/ASA condition, participants took low-dose ASA (81 mg/day) daily in the evening (22:00) during the at-home phase and the subsequent in-laboratory stay. In the sleep restriction/placebo and control sleep/placebo conditions, participants took placebo daily. Each in-laboratory stay started with 2 nights with a sleep opportunity of 8 h/night (23:00–07:00) for adaptation and baseline measurements. Under the two sleep restriction conditions, participants were exposed to 5 nights of sleep restricted to a sleep opportunity of 4 h/night (03:00–07:00) followed by 3 nights of recovery sleep with a sleep opportunity of 8 h/night. Under the control sleep condition, participants had a sleep opportunity of 8 h/night throughout the in-laboratory stay. During each in-laboratory stay, participants had 3 days of intensive monitoring (at baseline, 5th day of sleep restriction/control sleep, and 2nd day of recovery sleep). Variables, including pro-inflammatory immune cell function, C-reactive protein (CRP), and actigraphy-estimated measures of sleep, were analyzed using generalized linear mixed models. ResultsLow-dose ASA administration reduced the interleukin (IL)-6 expression in LPS-stimulated monocytes (p<0.05 for condition*day) and reduced serum CRP levels (p<0.01 for condition) after 5 nights of sleep restriction compared to placebo administration in the sleep restriction condition. Low-dose ASA also reduced the amount of cyclooxygenase (COX)-1/COX-2 double positive cells among LPS-stimulated monocytes after 2 nights of recovery sleep following 5 nights of sleep restriction compared to placebo (p<0.05 for condition). Low-dose ASA further decreased wake after sleep onset (WASO) and increased sleep efficiency (SE) during the first 2 nights of recovery sleep (p<0.001 for condition and condition*day). Baseline comparisons revealed no differences between conditions for all of the investigated variables (p>0.05 for condition). ConclusionThis study shows that inflammatory responses to sleep restriction can be reduced by preemptive administration of low-dose ASA. This finding may open new therapeutic approaches to prevent or control inflammation and its consequences in those experiencing sleep deficiencies. Trial RegistrationClinicalTrials.gov NCT03377543.