Evidence that sleep deprivation downregulates dopamine D2R in ventral striatum in the human brain

Network analysis of smoking-related sleep characteristics in Chinese adults

The associations between multiple sleep characteristics and smoking behavior are inconsistent, and it is unclear which sleep characteristics are most crucial for tobacco prevention. This study aimed to explore the associations between smoking status/intensity and multiple sleep characteristics and to identify the potential core domain of smoking-related sleep using network analysis. Data were obtained from a survey of cancer-related risk factors among Chinese adults. Logistic regression models were used to quantify the associations between sleep characteristics and smoking status/intensity. Network analyses were employed to identify the core sleep characteristics. A total of 5,228 participants with a median age of 44 years old were included in the study. Current smoking was significantly positively associated with long nap time, difficulty falling asleep, late bedtime, getting up after 7 am, and waking up earlier than expected. There was significant positive association between current smoking and short sleep duration in young adults under 45 years old. Late bedtime and getting up after 7 am were only associated with current heavy smoking, but not current light smoking. Network analyses showed that multiple smoking-related sleep characteristics were interconnected, with difficulty falling asleep and late bedtime as central characteristics in the network. The study found that the associations between sleep characteristics and smoking varied by age and smoking intensity and highlights the potential benefits of sleep health promotion in smoking cessation, with a particular focus on difficulty falling asleep and late bedtime.

Association between sleep and myopia in children and adolescents: a systematic review and meta-analysis

PURPOSE

There is a scarcity of literature focusing on sleep's impact on myopia in children despite an epidemic rise of myopia among the age group and the importance of early prevention. As such, this systematic review-meta-analysis aims to evaluate the association between various aspects of sleep and myopia in children and adolescents aged 0-19 years.

METHODS

We searched PubMed, EMBASE, and Cochrane Library on 08/12/2022 for studies reporting sleep in relation to myopia among children and adolescents. Myopia was defined as spherical equivalent refraction < -0.5 diopter. The primary outcome was the relationship between sleep duration and myopia prevalence. Secondary outcomes include the effect of sleep quality, bedtime, and waketime on myopia prevalence, incidence, and progression. Odds ratio (OR) was estimated with a 95% confidence interval (95% CI).

RESULTS

Eighteen studies (49,277 participants) were included in the review, and six studies (14,116 participants) were included in the meta-analysis for the primary outcome. There was no significant correlation between sleep and myopia prevalence (OR = 0.905, 95% CI = 0.782 to 1.047). Some studies suggested that better sleep quality (2 of 6 studies), earlier bedtime (3 of 5 studies), and later waketimes (2 of 3 studies) had protective effects on myopia.

CONCLUSION

Sleep duration did not affect myopia prevalence in children, while other aspects of sleep had plausible but inconclusive impacts on myopia development and progression. More research with diverse populations and standardized methods of reporting is needed.

Sleep disruptions and the pathway to psychosis: An in-depth case and literature review

Key Clinical Message

The case highlights an unusual presentation where sleep issues preceded psychotic symptoms, implying link between disrupted sleep and psychosis onset. Earlier symptoms were viewed as depression but may have signaled psychosis exacerbated by insomnia.

Abstract

Sleep disorders, prevalent yet frequently overlooked in individuals with psychotic disorders, have significant associations with the onset and severity of psychosis. Here we describe the case of a patient who first presented with insomnia, but whose condition improved with the use of risperidone and was diagnosed with first-episode psychosis. Multiple studies emphasize the critical relationship between sleep disturbances and psychosis, particularly in the lead-up to first-episode psychosis. Structural abnormalities in the brain, notably the thalamus, combined with neurotransmitter imbalances involving dopamine and acetylcholine, seem pivotal in this interrelation. The connection between dopamine, sleep disturbances, and psychosis, specifically the role of D2 dopamine receptors, highlights a potential pathway bridging sleep irregularities with psychosis. The study underscores the need for further research to delineate the relationship between sleep disturbances and psychosis and to assess the efficacy of various therapeutic interventions targeting both conditions.

Using caffeine as a chemical means to induce flow states

Flow is an intrinsically rewarding state characterised by positive affect and total task absorption. Because cognitive and physical performance are optimal in flow, chemical means to facilitate this state are appealing. Caffeine, a non-selective adenosine receptor antagonist, has been emphasized as a potential flow-inducer. Thus, we review the psychological and biological effects of caffeine that, conceptually, enhance flow. Caffeine may facilitate flow through various effects, including: i) upregulation of dopamine D1/D2 receptor affinity in reward-associated brain areas, leading to greater energetic arousal and 'wanting'; ii) protection of dopaminergic neurons; iii) increases in norepinephrine release and alertness, which offset sleep-deprivation and hypoarousal; iv) heightening of parasympathetic high frequency heart rate variability, resulting in improved cortical stress appraisal, v) modification of striatal endocannabinoid-CB1 receptor-signalling, leading to enhanced stress tolerance; and vi) changes in brain network activity in favour of executive function and flow. We also discuss the application of caffeine to treat attention deficit hyperactivity disorder and caveats. We hope to inspire studies assessing the use of caffeine to induce flow.

The effect of anxiety on sleep disorders in medical students: a moderated mediation model

The relationship between anxiety and sleep disorders is a key research topic in the academic community. However, evidence on the mechanism through which anxiety influences sleep disorders remains limited. The purpose of this study was to investigate the roles of flourishing and neuroticism in the mechanism through which anxiety influences sleep disorders in medical students. We constructed a moderated mediation model and tested the mediating role of flourishing and the moderating role of neuroticism in medical college students. The results showed that: (1) anxiety was significantly and positively related to sleep disorders and significantly and negatively related to flourishing; flourishing was significantly and negatively related to sleep disorders; neuroticism was significantly and positively related to sleep disorders; (2) flourishing had a mediation effect on the relationship between anxiety and sleep disorders; (3) neuroticism moderated the process through which flourishing mediated the effect of anxiety on sleep disorders. Our research expands the literature on the mechanism underlying the effects of anxiety on sleep disorders and provides insights into the potential prevention and intervention of sleep and emotional problems in medical students.

Clinical Phenotypes Supporting the Relationship Between Sleep Disturbance and Impairment of Placebo Effects

Lack of good sleep or insomnia can lead to many health issues, including an elevated risk of cardiovascular disease, obesity, fatigue, low mood, and pain. While chronic pain negatively impacts sleep quality, the relationship between descending pain modulatory systems like placebo effects and sleep quality is not thoroughly known. We addressed this aspect in a cross-sectional study in participants with chronic pain. Placebo effects were elicited in a laboratory setting using thermal heat stimulations delivered with visual cues using classical conditioning and verbal suggestions. We estimated the levels of insomnia severity with the Insomnia Severity Index and the sleep quality with the Pittsburg Sleep Quality Index. The previous night's sleep continuity was assessed as total sleep time, sleep efficiency, and sleep midpoint the night before the experiment. 277 people with chronic pain and 189 pain-free control individuals participated. Participants with chronic pain and insomnia showed smaller placebo effects than those with chronic pain without insomnia. Similarly, poor sleep quality was associated with reduced placebo effects among participants with chronic pain. Clinical anxiety measured by Depression Anxiety Stress Scales partially mediated these effects. In contrast, placebo effects were not influenced by the presence of insomnia or poor sleep quality in pain-free participants. Sleep continuity the night before the experiment did not influence the placebo effects. Our results indicate that participants who experience insomnia and/or poor sleep quality and chronic pain have smaller placebo effects, and that the previous night sleep continuity does not influence the magnitude of placebo effects. PERSPECTIVE: This study examined the relationship between sleep disturbances and experimentally induced placebo effects. We found that individuals with chronic pain who experience insomnia and poor sleep quality demonstrated reduced placebo effects compared to their counterparts with good sleep quality and no insomnia.

Major Depressive Disorder Prediction Based on Sleep-Wake Disorders Symptoms in US Adolescents: A Machine Learning Approach from National Sleep Research Resource

Background

There is substantial evidence from previous studies that abnormalities in sleep parameters associated with depression are demonstrated in almost all stages of sleep architecture. Patients with symptoms of sleep-wake disorders have a much higher risk of developing major depressive disorders (MDD) compared to those without.

Objective

The aim of the present study is to establish and compare the performance of different machine learning models based on sleep-wake disorder symptoms data and to select the optimal model to interpret the importance of sleep-wake disorder symptoms to predict MDD occurrence in adolescents.

Methods

We derived data for this work from 2020 to 2021 Assessing Nocturnal Sleep/Wake Effects on Risk of Suicide Phase I Study from National Sleep Research Resource. Using demographic and sleep-wake disorder symptoms data as predictors and the occurrence of MDD measured base on the center for epidemiologic studies depression scale as an outcome, the following six machine learning predictive models were developed: eXtreme Gradient Boosting model (XGBoost), Light Gradient Boosting mode, AdaBoost, Gaussian Naïve Bayes, Complement Naïve Bayes, and multilayer perceptron. The models' performance was assessed using the AUC and other metrics, and the final model's predictor importance ranking was explained.

Results

XGBoost is the optimal predictive model in comprehensive performance with the AUC of 0.804 in the test set. All sleep-wake disorder symptoms were significantly positively correlated with the occurrence of adolescent MDD. The insomnia severity was the most important predictor compared with the other predictors in this study.

Conclusion

This machine learning predictive model based on sleep-wake disorder symptoms can help to raise the awareness of risk of symptoms between sleep-wake disorders and MDD in adolescents and improve primary care and prevention.

Sleep and Pain: A Role for the Anterior Cingulate Cortex, Nucleus Accumbens, and Dopamine in the Increased Pain Sensitivity Following Sleep Restriction

Persistent pain conditions and sleep disorders are public health problems worldwide. It is widely accepted that sleep disruption increases pain sensitivity; however, the underlying mechanisms are poorly understood. In this study, we used a protocol of 6 hours a day of total sleep deprivation for 3 days in rats to advance the understanding of these mechanisms. We focused on gender differences and the dopaminergic mesocorticolimbic system. The findings demonstrated that sleep restriction (SR) increased pain sensitivity in a similar way in males and females, without inducing a significant stress response. This pronociceptive effect depends on a nucleus accumbens (NAc) neuronal ensemble recruited during SR and on the integrity of the anterior cingulate cortex (ACC). Data on indirect dopaminergic parameters, dopamine transporter glycosylation, and dopamine and cyclic adenosine monophosphate (AMP)-regulated phosphoprotein-32 phosphorylation, as well as dopamine, serotonin, and norepinephrine levels, suggest that dopaminergic function decreases in the NAc and ACC after SR. Complementarily, pharmacological activation of dopamine D2, but not D1 receptors either in the ACC or in the NAc prevents SR from increasing pain sensitivity. The ACC and NAc are the main targets of dopaminergic mesocorticolimbic projections with a key role in pain modulation. This study showed their integrative role in the pronociceptive effect of SR, pointing to dopamine D2 receptors as a potential target for pain management in patients with sleep disorders. These findings narrow the focus of future studies on the mechanisms by which sleep impairment increases pain sensitivity. PERSPECTIVE: This study demonstrates that the pronociceptive effect of SR affects similarly males and females and depends on a NAc neuronal ensemble recruited during SR and on the integrity of the ACC. Findings on dopaminergic function support dopamine D2 receptors as targets for pain management in sleep disorders patients.

Dozing Off With Drosophila: The Effect of Disrupted Circadian Rhythms and Sleep Disturbance on Mortality, Mood, and Addiction

Many environmental factors can disrupt sleep and circadian rhythms, yet the consequences of such disruptions are poorly understood. The main goals of this project were to study the effects of disrupted circadian rhythms and sleep disturbance on Drosophila melanogaster's: (1) lifespan, (2) depression-like behaviors, and (3) propensity to consume caffeine-containing media. Three experimental groups were used: controls, Circadian Dysfunction (CD), and Sleep Disturbance (SD). Circadian disruption (CD): used flies with Tim01 mutation, which eliminates circadian behavioral rhythms. Sleep disturbance (SD): used flies subjected to hourly light exposure and manual mechanical disruption, for 48 hours. To assess the effect on lifespan, the percent of flies surviving over time, within each group, was calculated. Impaired geotaxis, or loss of climbing motivation, was assessed as a measure of a depression-like state. Preference for caffeine-containing food was evaluated using a choice chamber where caffeine enriched, and regular media were presented to flies. Group differences were analyzed with survival curves. Chi-square tests were used for the categorical variables. Survival curve analysis showed that Flies with the timeless gene mutation (tim01) have a significantly shorter lifespan than controls. Geotaxis was not significantly impaired by sleep disturbance, but it was negatively affected by circadian dysfunction. Both the Circadian Dysfunction and Sleep Disturbance groups showed a preference for caffeine-containing food, after 72 hours of exposure to it, although the Circadian Dysfunction group was much more affected than the Sleep Disturbance group. Sleep and circadian disturbances can negatively influence physical and mental wellbeing and the accompanying molecular mechanisms, as well as disrupted brain physiology, must be studied. It is critical to identify and minimize social and environmental disruptors of such biological rhythms.

Effects of electroacupuncture on the ventral tegmental area- nucleus accumbens dopamine pathway in rats with chronic sleep deprivation

BACKGROUND

Insomnia is a well-recognized clinical sleep disorder in the adult population. It has been established that acupuncture has a clinical effects in the treatment of insomnia; however, research on the underlying neural circuits involved in these effects is limited.

METHODS

The modified multiple platform method (MMPM) was used to establish a rat model of chronic sleep deprivation (CSD). Forty rats were randomly divided into a control (Con) group, (untreated) CSD group, electroacupuncture-treated CSD group (CSD + EA) and estazolam-treated CSD group (CSD + Estazolam group) with n = 10 per group. In the CSD + EA group, EA was delivered at Yintang and unilateral HT7 (left and right treated every other day) with continuous waves (2 Hz frequency) for 30 min/day over 7 consecutive days. In the CSD + Estazolam groups, estazolam was administered by oral gavage (0.1 mg/kg) for 7 consecutive days. The open field test (OFT) was used to observe behavioral changes. Immunofluorescence assays and enzyme-linked immunosorbent assay (ELISA) were used to observe the effects of EA on the ventral tegmental area (VTA)-nucleus accumbens (NAc) dopamine (DA) pathway. We also assessed the effects of EA on the expression of dopamine D1 receptor (D1R) and dopamine D2 receptor (D2R) in the NAc, which are the downstream targets of the VTA-NAc DA pathway.

RESULTS

After CSD was established by MMPM, rats exhibited increased autonomous activity and increased excitability of the VTA-NAc DA pathway, with increased VTA and NAc DA content, increased D1R expression and decreased D2R expression in the NAc. EA appeared to reduce the autonomous ability of CSD rats, leading to lower DA content in the VTA and NAc, reduced expression of D1R in the NAc and increased expression of D2R. Most importantly, EA produced effects similar to estazolam with respect to the general condition of rats with CSD and regulation of the VTA-NAc DA pathway.

CONCLUSIONS

The therapeutic effect of EA in chronic insomnia may be mediated by reduced excitability of the VTA-NAc DA pathway, with lower DA content in the VTA and NAc, downregulated expression of D1R in the NAc and increased expression of D2R.

Insomnia as a Risk Factor for Substance Use Disorders in Women

Gender differences exist for both insomnia and substance use disorders. Women show a higher prevalence of insomnia and increased susceptibility to the effects of drugs than men. Importantly, a growing body of evidence suggests that insufficient sleep predicts and puts individuals at a higher risk for substance use and associated psychosocial problems. However, the role of insomnia in substance use disorders among women remains poorly understood. The present article discusses gender differences in insomnia and in substance use disorders and reviews evidence suggesting that an increased prevalence of insomnia may be a risk factor for substance use disorders in women.

Activation of the Hippocampal DRD2 Alleviates Neuroinflammation, Synaptic Plasticity Damage and Cognitive Impairment After Sleep Deprivation

Sleep loss is commonplace nowadays and profoundly impacts cognition. Dopamine receptor D2 (DRD2) makes a specific contribution to cognition, although the precise mechanism underlying how DRD2 affects the cognitive process after sleep deprivation remains unclear. Herein, we observed cognitive impairment and impaired synaptic plasticity, including downregulation of synaptophysin and PSD95, decreased postsynaptic density thickness, neuron complexity, and spine density in chronic sleep restriction (CSR) mice. We also observed downregulated hippocampal DRD2 and Cryab expression in the CSR mice. Meanwhile, NF-κB translocation from the cytoplasm to the nucleus occurred, indicating that neuroinflammation ensued. However, hippocampal delivery of the DRD2 agonist quinpirole effectively rescued these changes. In vitro, quinpirole treatment significantly decreased the release of proinflammatory cytokines in microglial supernatant, indicating a potential anti-neuroinflammatory effect of Drd2/Cryab/NF-κB in CSR mice. Our study provided the evidence that activation of the Drd2 may relieve neuroinflammation and improve sleep deprivation-induced cognitive deficits.

Sleep duration and depressive symptoms in Chinese middle-aged and older adults: The moderating effects of grip strength

BACKGROUND

Evidence on the combined effect of sleep duration and grip strength on depressive symptoms is scarce. This study aimed to explore the moderating effect of grip strength on the association between sleep duration and depressive symptoms in a large cohort of middle-aged and older adults.

METHOD

Data were extracted from the China Health and Retirement Longitudinal Study (CHARLS) 2011-2018 wave. Grip strength and sleep duration were assessed by dynamometer and self-report, respectively. Depressive symptoms were determined by the Centre for Epidemiological Studies Depression scale (CESD-10). Multivariable cox regression model was used to explore the associations between sleep duration, and depressive symptoms, and assess moderation by grip strength.

RESULTS

A total of 4337 participants aged 57.0 ± 8.1 years (45.1 % females) were included in this study. During the 7-year follow up period, 1508 participants developed depressive symptoms. Short sleep duration (<6 h/d) was significantly associated with an increased risk of depressive symptoms [Hazard ratio (HR):1.24, 95 % confidence interval (CI):1.09, 1.40)]. This association remained in individuals with the low (HR:1.22, 95%CI:1.00, 1.49) and middle grip strength (HR:1.32, 95%CI: 1.07, 1.63), but attenuated in individuals with high grip strength (HR:1.11, 95%CI: 0.86, 1.43).

CONCLUSIONS

High grip strength mitigated the association between short sleep duration and higher risk of depressive symptoms. Thus, improving sleep duration and strengthening muscle strength are recommended to prevent depressive symptoms in middle-aged and older adults.

The association between sleep duration and risk of myopia in Chinese school-aged children: a cross-sectional study

BACKGROUND

Myopia is one of the most commonly diagnosed refractive disorders worldwide. Identifying risk factors for myopia at an early age may help to characterize children who would benefit most from individualized lifestyle advice and early interventions. The influence of sleep duration on myopia risk remains controversial and thus needs to be evaluated.

METHODS

A population-based cross-sectional study of Chinese school-aged children was conducted. Information on sleep duration was derived. The association between sleep duration and myopia risk was investigated by logistic regression analysis.

RESULTS

Myopia prevalence among 9530 Chinese school-aged children was 75.4% and decreased from 84.9%, 76.5%, 65.8%, to 61.3% along with the extension of sleep duration. Univariate logistic regression found longer sleep duration of 8-9 h (OR = 0.58, 95% CI: 0.51-0.66), 9-10 h (OR = 0.34, 95% CI: 0.30-0.39), and ≥ 10 h (OR = 0.28, 95% CI: 0.24-0.33) were protective factors for myopia in all participants (P for trend < 0.001). In the multivariate analyses, sleep duration was inversely associated with the risk of myopia, and a dose-effect relationship was observed when the analysis was split by age category.

CONCLUSIONS

Long sleep duration was associated with decreased risk of myopia in Chinese school-aged children.

Association between sleep duration, sleep quality, bedtime and myopia: A systematic review and meta-analysis

BACKGROUND

We performed a systematic review and meta-analysis to investigate the links between different sleep characteristics and risk of myopia.

METHODS

PubMed, EMBASE, Web of Science, the Cochrane Library, PsycINFO, Wanfang, and CNKI were searched from inception to August 26, 2022, without any language restriction. Cross-sectional, case-control, or cohort studies that explored the association between sleep duration, sleep quality, bedtime, and myopia were included. NIH quality assessment tools were used to assess the methodological quality of included studies. Random-effect or fixed-effect models were used to pool the associations according to whether there is heterogeneity.

RESULTS

A total of 31 studies with 205 907 participants were included in the final analysis (25 studies reporting sleep duration; four studies examining sleep quality and six studies evaluating bedtime). Compared to reference sleep duration, sufficient sleep duration (OR = 0.63, 95% CI = 0.51-0.78) was associated with a lower risk of myopia, and short sleep duration (OR = 1.66, 95% CI = 1.14-2.42) was associated with a higher risk of myopia. In addition, poor sleep quality (OR = 1.24, 95% CI = 1.05-1.47) was associated with a higher risk of myopia while late bedtime (OR = 1.30, 95% CI = 0.96-1.75) was not significantly associated with an increased risk of myopia.

CONCLUSIONS

Alteration in sleep duration and sleep quality may influence the risk of myopia. Well-designed cohort studies are needed in future investigations to identify a causal relationship between different sleep characteristics and myopia.

Brain Dopamine-Clock Interactions Regulate Cardiometabolic Physiology: Mechanisms of the Observed Cardioprotective Effects of Circadian-Timed Bromocriptine-QR Therapy in Type 2 Diabetes Subjects

Despite enormous global efforts within clinical research and medical practice to reduce cardiovascular disease(s) (CVD), it still remains the leading cause of death worldwide. While genetic factors clearly contribute to CVD etiology, the preponderance of epidemiological data indicate that a major common denominator among diverse ethnic populations from around the world contributing to CVD is the composite of Western lifestyle cofactors, particularly Western diets (high saturated fat/simple sugar [particularly high fructose and sucrose and to a lesser extent glucose] diets), psychosocial stress, depression, and altered sleep/wake architecture. Such Western lifestyle cofactors are potent drivers for the increased risk of metabolic syndrome and its attendant downstream CVD. The central nervous system (CNS) evolved to respond to and anticipate changes in the external (and internal) environment to adapt survival mechanisms to perceived stresses (challenges to normal biological function), including the aforementioned Western lifestyle cofactors. Within the CNS of vertebrates in the wild, the biological clock circuitry surveils the environment and has evolved mechanisms for the induction of the obese, insulin-resistant state as a survival mechanism against an anticipated ensuing season of low/no food availability. The peripheral tissues utilize fat as an energy source under muscle insulin resistance, while increased hepatic insulin resistance more readily supplies glucose to the brain. This neural clock function also orchestrates the reversal of the obese, insulin-resistant condition when the low food availability season ends. The circadian neural network that produces these seasonal shifts in metabolism is also responsive to Western lifestyle stressors that drive the CNS clock into survival mode. A major component of this natural or Western lifestyle stressor-induced CNS clock neurophysiological shift potentiating the obese, insulin-resistant state is a diminution of the circadian peak of dopaminergic input activity to the pacemaker clock center, suprachiasmatic nucleus. Pharmacologically preventing this loss of circadian peak dopaminergic activity both prevents and reverses existing metabolic syndrome in a wide variety of animal models of the disorder, including high fat-fed animals. Clinically, across a variety of different study designs, circadian-timed bromocriptine-QR (quick release) (a unique formulation of micronized bromocriptine-a dopamine D2 receptor agonist) therapy of type 2 diabetes subjects improved hyperglycemia, hyperlipidemia, hypertension, immune sterile inflammation, and/or adverse cardiovascular event rate. The present review details the seminal circadian science investigations delineating important roles for CNS circadian peak dopaminergic activity in the regulation of peripheral fuel metabolism and cardiovascular biology and also summarizes the clinical study findings of bromocriptine-QR therapy on cardiometabolic outcomes in type 2 diabetes subjects.

Effects of red light on sleep and mood in healthy subjects and individuals with insomnia disorder

Introduction

This study aimed to determine the influence of red light on objective sleep and the relationship between mood and sleep among individuals with insomnia disorder (ID).

Method

57 individuals with insomnia symptoms and 57 healthy participants were randomly divided into three groups (red- and white-light groups, and the black control group), which received different light treatments for 1 h before bedtime. The emotions and subjective alertness of participants were evaluated using Positive and Negative Affect Schedule scales (PANAS) and Karolinska Sleepiness Scale (KSS), their sleeping data were recorded using polysomnography (PSG).

Result

The negative emotion scores were higher in the healthy subject-red light (HS-RL) group than in the HS-white light (WL) and HS-black control (BC) groups (p < 0.001). The anxiety and negative emotion scores were higher in the ID-RL group than in the ID-WL and ID-BC groups (p = 0.007 and p < 0.001, respectively). The KSS scores were lower in the RL group than in the WL and BC groups for both HS and ID group (both p < 0.001). The SOL was shorter in the HS-RL group than in HS-WL group (p = 0.019). Compared with the HS-BC group, the HS-RL group had an increase in microarousal index (MAI) and N1% (p = 0.034 and p = 0.021, respectively), while the total sleep time (TST) and sleep efficiency (SE) decreased (p = 0.001 and p < 0.001, respectively). Compared with the ID-WL group, the SOL was shorter in the ID-RL group (p = 0.043), while TST, SE, number of microarousals (NMA), and numbers of cycles of REM period were increased (p = 0.016, p = 0.046, p = 0.001, and p = 0.041, respectively). Compared with the ID-BC group, the ID-RL group had increases in the SOL, WASO, and the numbers of cycles and NMA in REM period (p = 0.038, p = 0.005, p = 0.045, and p = 0.033, respectively), and a decrease in SE (p = 0.014). The effects of ID-WL (vs. ID-RL group) and ID-BC (vs. ID-RL group) on SOL were mediated by negative emotions (mediating effects were - 37.626 and - 33.768, respectively).

Conclusion

Red light can increase subjective alertness, anxiety, and negative emotions in both healthy subjects and people with ID, which can affect sleep directly or indirectly via the mediating effect of negative emotions.

The nucleus accumbens functional connectivity in patients with insomnia using resting-state fMRI

Background

The aim of this study was to investigate the functional abnormalities between the nucleus accumbens (NAc) and the whole brain in individuals with Insomnia Disorder (ID) using resting-state functional magnetic resonance imaging (fMRI). Additionally, the study aimed to explore the underlying neural mechanisms of ID.

Methods

We enrolled 18 participants with ID and 16 normal controls (NC). Resting-state functional connectivity (FC) between the NAc and the whole brain voxels was calculated and compared between the two groups to identify differential brain region. Receiver operating characteristic (ROC) curve analysis was employed to assess the ability of differential features to distinguish between groups. Furthermore, Pearson correlation analysis was performed to examine the relationship between neurocognitive scores and differential features.

Results

The ID group exhibited significantly reduced FC values in several brain regions, including the right supplementary motor area, the bilateral middle frontal gyrus, the bilateral median cingulate and paracingulate gyri and the left precuneus. The area under the curve (AUC) of the classification model based on FC in these brain regions was 83.3%. Additionally, the abnormal functional changes observed in ID patients were positively correlated with the Fatigue Severity Scale (R = 0.650, p = 0.004).

Conclusion

These findings suggest that the NAc may play a crucial role in the diagnosis of ID and could serve as a potential imaging biomarker, providing insights into the underlying neural mechanisms of the disorder.

Sleep health dimensions are associated with next-day symptoms in young adults with type 1 diabetes

OBJECTIVE

We investigated intra-individual reciprocal associations between sleep health dimensions (individual and composite) and symptoms among young adults with type 1 diabetes (T1D).

DESIGN AND MEASUREMENTS

Cross-lagged multilevel models were used to analyze electronic diary-reported sleep and symptom patterns over 7 days at waketime in 42 young adults with T1D. Sleep health dimensions included regularity, satisfaction, alertness, timing, efficiency (percentage of time spent asleep), and duration (total sleep time) and symptoms included mood, fatigue, and pain. Covariates included biological sex and age.

SETTING AND PARTICIPANTS

We recruited young adults (mean age 21.5 ± 2.1 years, HbA1c 6.8%, 85% female, 10% gender minority) with T1D for at least 6 months and no other major medical or psychiatric comorbidity from social media platforms, the College Diabetes Network, and ResearchMatch.

RESULTS

On days with a better sleep health composite, participants reported lower next-day symptoms (higher mood, lower fatigue, and lower pain) and on days when participants reported lower symptoms, participants reported better sleep health (as a composite). Several individual sleep health dimensions led to lower next-day symptoms (eg, higher satisfaction, alertness, and efficiency and higher mood); however, symptoms were no longer predictive of next-day sleep when controlling for prior day sleep.

CONCLUSIONS

Optimal sleep health is an antecedent of fewer next day symptoms. Sleep health dimensions likely have positive additive effects on lower symptoms as some of the individual sleep health dimensions were not significantly associated with some symptoms among young adults with T1D.

Obstructive Sleep Apnea and Striatal Dopamine Availability in Parkinson's Disease

BACKGROUND

Sleep disorders are frequently associated with Parkinson's disease. Obstructive sleep apnea syndrome is one of these sleep disorders and is associated with the severity of motor symptoms in Parkinson's disease. Obstructive sleep apnea can lead to dopaminergic neuronal cell degeneration and may impair the clearance of α-synuclein in Parkinson's disease. Striatal dopamine uptake is a surrogate marker of nigral dopaminergic cell damage.

OBJECTIVE

We aimed to investigate the differences in striatal dopamine availability between Parkinson's disease patients with or without obstructive sleep apnea.

METHODS

A total of 85 de novo and nonmedicated Parkinson's disease patients were enrolled. Full-night polysomnography was performed for all patients, and obstructive sleep apnea was diagnosed as apnea/hypopnea index ≥5. Positron emission tomography was performed with 18 F-N-(3-fluoropropyl)-2β-carbon ethoxy-3β-(4-iodophenyl) nortropane, and the regional standardized-uptake values were analyzed using a volume-of-interest template and compared between groups with or without obstructive sleep apnea.

RESULTS

Dopamine availability in the caudate nucleus of the obstructive sleep apnea group was significantly lower than that of the nonobstructive sleep apnea group. On subgroup analysis, such association was found in female but not in male patients. In other structures (putamen, globus pallidus, and thalamus), dopamine availability did not differ between the two groups.

CONCLUSION

This study supports the proposition that obstructive sleep apnea can contribute to reduced striatal dopamine transporter availability in Parkinson's disease. Additional studies are needed to assess the causal association between obstructive sleep apnea and the neurodegenerative process in Parkinson's disease. © 2023 International Parkinson and Movement Disorder Society.

Associations between resting state brain activity and A1 adenosine receptor availability in the healthy brain: Effects of acute sleep deprivation

Introduction

Previous resting-state fMRI (Rs-fMRI) and positron emission tomography (PET) studies have shown that sleep deprivation (SD) affects both spontaneous brain activity and A1 adenosine receptor (A1AR) availability. Nevertheless, the hypothesis that the neuromodulatory adenosinergic system acts as regulator of the individual neuronal activity remains unexplored.

Methods

Therefore, fourteen young men underwent Rs-fMRI, A1AR PET scans, and neuropsychological tests after 52 h of SD and after 14 h of recovery sleep.

Results

Our findings suggested higher oscillations or regional homogeneity in multiple temporal and visual cortices, whereas decreased oscillations in cerebellum after sleep loss. At the same time, we found that connectivity strengths increased in sensorimotor areas and decreased in subcortical areas and cerebellum.

Discussion

Moreover, negative correlations between A1AR availability and rs-fMRI metrics of BOLD activity in the left superior/middle temporal gyrus and left postcentral gyrus of the human brain provide new insights into the molecular basis of neuronal responses induced by high homeostatic sleep pressure.

Associations of social jetlag and insomnia symptoms with depressive symptoms among Chinese adolescents: A large population-based study

OBJECTIVE

This study aimed to evaluate the associations of social jetlag and insomnia symptoms with depressive symptoms among adolescents.

METHODS

A total of 37,871 junior high students completed an online survey between May 24th and Jun 5th, 2022. Insomnia symptoms were assessed by three items based on the Diagnostic and Statistical Manual of Mental Disorders criteria. Social jetlag and depressive symptoms were evaluated by the Munich Chronotype Questionnaire and the Patient Health Questionnaire, respectively. Restricted cubic splines were used to explore the relationship between social jetlag and depressive symptoms. Joint effects of social jetlag and insomnia symptoms on depressive symptoms were estimated using additive interaction models.

RESULTS

The prevalence of depressive symptoms was 13.1%. Depressive symptoms were more common in adolescents with social jetlag ≥2 h (OR: 1.51, 95% CI: 1.39-1.65) and insomnia symptoms (OR: 6.91, 95% CI: 6.41-7.44). There was a J-shaped relationship between social jetlag and depressive symptoms when we took social jetlag as a continuous variable. Moreover, a positive additive interaction of social jetlag ≥2 h and insomnia symptoms on depressive symptoms was found in female adolescents (RERI: 2.30, 95% CI: 0.11-4.49).

CONCLUSIONS

Our findings suggested that social jetlag ≥2 h and insomnia are related to the occurrence of depressive symptoms in adolescents. Their coexistence additively enhances the strength of the association with depressive symptoms. Early screening and intervention for insomnia, as well as methods to reduce social jetlag, should be comprised as part of preventive strategies for depression in adolescents.

Sleep benefit in patients with Parkinson's disease is associated with the dopamine transporter expression in putamen

PURPOSE

Sleep benefit (SB) is a well-known phenomenon in patients with Parkinson's disease (PD); however, the mechanisms underlying this phenomenon remain unclear. This study aimed to evaluate whether the SB phenomenon in PD patients is associated with dopamine transporter (DAT) expression levels in the striatum.

METHODS

The data of 125 PD patients were collected and divided into SB (n = 61) and non-SB (nSB) groups (n = 54) depending on whether they had SB or not. DAT expression on both sides of the striatum in PD patients was measured using 2b-carbomethoxy-3b-(4-trimethylstannylphenyl) tropane (11C-CFT) positron emission tomography imaging. The clinical variables, sleep scores, and striatum 11C-CFT uptake index of PD patients between the SB and nSB groups were compared. The associations of clinical variables, sleep scores, and striatum 11C-CFT uptake index with the SB variable were analyzed using logistic regression analysis. A receiver operating characteristic (ROC) curve was used to evaluate the diagnostic value of the striatum 11C-CFT uptake index in distinguishing SB patients from nSB patients.

RESULTS

The tremor subtype ratio (P = 0.011), levodopa equivalent daily dose (LEDD) (P < 0.001), sleep efficiency score (P = 0.025), habitual sleep efficiency (P = 0.012), and night sleep duration (P = 0.005) in the SB group were significantly different from those in the nSB group. The 11C-CFT uptake index in both the contralateral and ipsilateral striata in the SB group was significantly higher than that in the nSB group (P < 0.05). The binary logistic regression showed that SB variables were significantly and independently associated with tremor subtype (P = 0.048), LEDD (P = 0.021), sleep duration at night (P = 0.035), 11C-CFT uptake index in the contralateral (P = 0.013) and ipsilateral (P = 0.019) putamen in PD patients after correction for important clinical confounders. ROC analysis showed that the 11C-CFT uptake index on the onset side of the putamen had a high capacity (AUC: 0.916) to distinguish SB patients from nSB patients with high sensitivity (83.33 %) and specificity (88.89 %).

CONCLUSION

DAT expression in the putamen was associated with the SB phenomenon in PD patients, and the putamen DAT expression level could predict the SB phenomenon in PD patients.

Sleep Deprivation Induces Dopamine System Maladaptation and Escalated Corticotrophin-Releasing Factor Signaling in Adolescent Mice

Sleep disruption is highly associated with the pathogenesis and progression of a wild range of psychiatric disorders. Furthermore, appreciable evidence shows that experimental sleep deprivation (SD) on humans and rodents evokes anomalies in the dopaminergic (DA) signaling, which are also implicated in the development of psychiatric illnesses such as schizophrenia or substance abuse. Since adolescence is a vital period for the maturation of the DA system as well as the occurrence of mental disorders, the present studies aimed to investigate the impacts of SD on the DA system of adolescent mice. We found that 72 h SD elicited a hyperdopaminergic status, with increased sensitivity to the novel environment and amphetamine (Amph) challenge. Also, altered neuronal activity and expression of striatal DA receptors were noticed in the SD mice. Moreover, 72 h SD influenced the immune status in the striatum, with reduced microglial phagocytic capacity, primed microglial activation, and neuroinflammation. The abnormal neuronal and microglial activity were putatively provoked by the enhanced corticotrophin-releasing factor (CRF) signaling and sensitivity during the SD period. Together, our findings demonstrated the consequences of SD in adolescents including aberrant neuroendocrine, DA system, and inflammatory status. Sleep insufficiency is a risk factor for the aberration and neuropathology of psychiatric disorders.

Insomnia and multiple health outcomes: umbrella review of meta-analyses of prospective cohort studies

OBJECTIVES

To evaluate existing evidence of prospective cohort studies on associations between insomnia and multiple health outcomes.

STUDY DESIGN

An umbrella review of meta-analyses of prospective cohort studies.

METHODS

A systematic search was undertaken in Pubmed, Embase, Cochrane, and Web of Science from inception to October 2021 to find meta-analyses of prospective cohort studies investigating the association of insomnia with any health outcome. The summary relative risk (SRR) for each meta-analysis was recalculated with random-effects model. The methodological quality and the quality of evidence were assessed by the A Measurement Tool to Assess Systematic Reviews and Grading of Recommendations, Assessment, Development and Evaluation, respectively.

RESULTS

A total of 25 published meta-analyses of prospective cohort studies, reporting 63 SRRs for 29 unique outcomes were included. Insomnia was mainly related to cardiovascular outcomes and mental disorders. The former comprised atrial fibrillation (SRR: 1.30, 95% confidence interval: 1.26 to 1.35), cardiovascular diseases (1.45, 1.29 to 1.64), coronary heart disease (1.28, 1.10 to 1.50), myocardial infarction (1.42, 1.17 to 1.72), and stroke (1.55, 1.39 to 1.72). The latter involved alcohol abuse (1.35, 1.08 to 1.67), all mental disorders (2.16, 1.70 to 3.97), anxiety (3.23, 1.52 to 6.85), depression (2.31, 1.90 to 2.81), suicidal ideation (2.26, 1.79 to 2.86), suicidal attempt (1.99, 1.31 to 3.02), and suicidal death (1.72, 1.42 to 2.08). Besides, insomnia enhanced the risk of Alzheimer's disease (1.51, 1.06 to 2.14) and hyperlipidemia (1.64, 1.53 to 1.76).

CONCLUSION

Insomnia exhibits considerable adverse outcomes, primarily comprises cardiovascular outcomes and mental disorders, but further studies with robustly designed trials are needed to draw firmer conclusions.

Interventions recommended for myopia prevention and control among children and adolescents in China: a systematic review

In 2018, a consortium of government bodies in China led by the Ministry of Education released the Comprehensive Plan to Prevent Nearsightedness among Children and Teenagers (CPPNCT), aiming to reduce the incidence of myopia and control myopic progression in China. Recommendations span from home-based to school-based interventions, including time outdoors, physical activity, light exposure, near-work activity, screen time, Chinese eye exercises, diet and sleep. To date, the levels of evidence for this suite of interventions have not been thoroughly investigated. This review has summarised the evidence of the interventions recommended by the CPPNCT in myopia prevention and control. Thus, the following statements are supposed by the evidence: (1) Increasing time outdoors and reducing near-work time are effective in lowering incident myopia in school-aged children. (2) All interventions have a limited effect on myopia progression. Ongoing research may lead to a better understanding of the underlying mechanisms of myopia development, the interaction of different interventions and recommendations, confounding variables and their true effect on myopia prevention, and the identification of those most likely to respond to specific interventions. This field may also benefit from longer-term studies of the various interventions or strategies covered within this review article, to better understand the persistence of treatment effects over time and explore more novel approaches to myopia control.

Sleep disorders as a prospective intervention target to prevent drug relapse

Objective

The high rate of relapse has become the primary obstacle of drug rehabilitation. In this study, we explored the relationship between sleep disorders and relapse inclination in substance users, as well as the potential mediating mechanisms and corresponding interventions.

Methods

A total of 392 male substance users were recruited to complete the questionnaires on sleep disorders, quality of life and relapse inclination. On account of this, 60 participants with sleep disorders were randomly screened and allocated to the intervention and control groups. The former received 12 weeks of Health Qigong aimed at treating sleep disorders, whereas the latter performed their regular production work.

Results

Sleep disorders had a positive effect on relapse inclination, quality of life was a potential mediator of this relationship, and 12-week Health Qigong designed to treat sleep disorders improved not only their sleep quality but also their overall quality of life, which in turn reduce the tendency to relapse.

Conclusion

Current research not only explores the high-risk factors influencing relapse, but also develops customized intervention strategies, which have theoretical and practical implications for decreasing relapse and increasing abstinence.

[Sleep quality, emotional and behavioral disturbances, and eating behavior in adolescents with obesity: a network analysis-based model]

OBJECTIVE

To attempt to identify persistent associations between sleep quality, symptoms of emotional and behavioral disturbances, and characteristics of eating behavior in obese adolescents based on a network analysis.

MATERIAL AND METHODS

The study included 194 adolescents, aged 12-17 years (76 girls, 118 boys), with a confirmed diagnosis of obesity due to excess calories (ICD-10 code E66.0). Sleep quality was studied on the basis of the Adolescent Sleep Wake Scale (ASWS), emotional and behavioral disturbances were assessed with the Achenbach Youth Self-Report for Ages 11-18 (YSR), eating behavior - with the Dutch Eating Behavior Questionnaire (DEBQ). Network analysis was used to identify the most significant and stable associations between the studied indicators.

RESULTS

The association of poor sleep quality with manifestations of disinhibited behavior in the form of violations of the rules of behavior, aggressiveness, and impaired attention was revealed. Positive correlations between the manifestations of disinhibited behavior (primarily, rule-breaking behavior) and emotional eating behavior, which, in turn, had a positive relationship with external and a negative relationship with restrictive eating behavior, were noted. The disinhibited adolescent behavior is linked with uncontrolled food intake, which can contribute to the development of obesity.

CONCLUSION

Impaired sleep quality, symptoms of emotional and behavioral disorders, and eating disorders in obese adolescents present a stable and specific clinical pattern that should be taken into account when justifying therapy.

Sleep-mediated regulation of reward circuits: implications in substance use disorders

Our modern society suffers from both pervasive sleep loss and substance abuse-what may be the indications for sleep on substance use disorders (SUDs), and could sleep contribute to the individual variations in SUDs? Decades of research in sleep as well as in motivated behaviors have laid the foundation for us to begin to answer these questions. This review is intended to critically summarize the circuit, cellular, and molecular mechanisms by which sleep influences reward function, and to reveal critical challenges for future studies. The review also suggests that improving sleep quality may serve as complementary therapeutics for treating SUDs, and that formulating sleep metrics may be useful for predicting individual susceptibility to SUDs and other reward-associated psychiatric diseases.

Effect of sleep loss on pain-New conceptual and mechanistic avenues

Introduction

Sleep disturbances increase pain sensitivity in clinical and preclinical settings, but the precise mechanisms are unknown. This represents a major public health issue because of the growing sleep deficiency epidemic fueled by modern lifestyle. To understand the neural pathways at the intersection between sleep and pain processes, it is critical to determine the precise nature of the sleep disruptions that increase pain and the specific component of the pain response that is targeted.

Methods

We performed a review of the literature about sleep disturbances and pain sensitivity in humans and rodents by taking into consideration the targeted sleep stage (REMS, non-NREMS, or both), the amount of sleep lost, and the different types of sleep disruptions (partial or total sleep loss, duration, sleep fragmentation or interruptions), and how these differences might affect distinct components of the pain response.

Results

We find that the effects of sleep disturbances on pain are highly conserved among species. The major driver for pain hypersensitivity appears to be the total amount of sleep lost, while REMS loss by itself does not seem to have a direct effect on pain sensitivity. Sleep loss caused by extended wakefulness preferentially increases pain perception, whereas interrupted and limited sleep strongly dysregulates descending controls such as DNIC, especially in women.

Discussion

We discuss the possible mechanisms involved, including an increase in inflammatory processes, a loss of nociceptive inhibitory pathways, and a defect in the cognitive processing of noxious input.

Systemic inflammation enhances stimulant-induced striatal dopamine elevation in tobacco smokers

Immune-brain interactions influence the pathophysiology of addiction. Lipopolysaccharide (LPS)-induced systemic inflammation produces effects on reward-related brain regions and the dopamine system. We previously showed that LPS amplifies dopamine elevation induced by methylphenidate (MP), compared to placebo (PBO), in eight healthy controls. However, the effects of LPS on the dopamine system of tobacco smokers have not been explored. The goal of Study 1 was to replicate previous findings in an independent cohort of tobacco smokers. The goal of Study 2 was to combine tobacco smokers with the aforementioned eight healthy controls to examine the effect of LPS on dopamine elevation in a heterogenous sample for power and effect size determination. Eight smokers were each scanned with [¹¹C]raclopride positron emission tomography three times-at baseline, after administration of LPS (0.8 ng/kg, intravenously) and MP (40 mg, orally), and after administration of PBO and MP, in a double-blind, randomized order. Dopamine elevation was quantified as change in [¹¹C]raclopride binding potential (ΔBP_ND) from baseline. A repeated-measures ANOVA was conducted to compare LPS and PBO conditions. Smokers and healthy controls were well-matched for demographics, drug dosing, and scanning parameters. In Study 1, MP-induced striatal dopamine elevation was significantly higher following LPS than PBO (p = 0.025, 18 ± 2.9 % vs 13 ± 2.7 %) for smokers. In Study 2, MP-induced striatal dopamine elevation was also significantly higher under LPS than under PBO (p < 0.001, 18 ± 1.6 % vs 11 ± 1.5 %) in the combined sample. Smoking status did not interact with the effect of condition. This is the first study to translate the phenomenon of amplified dopamine elevation after experimental activation of the immune system to an addicted sample which may have implications for drug reinforcement, seeking, and treatment.

The Influence of Sleep Disturbance on Chronic Pain

PURPOSE OF REVIEW

The purpose of this review is to present an overview of common sleep disturbance pathologies and their impact on chronic pain, while examining various factors that are implicit in the relationship between sleep disturbance and chronic pain, including neurobiochemistry, anatomy, and systemic mediators, and reviewing recent and landmark literature.

RECENT FINDINGS

Earlier literature reviews and studies have introduced the bidirectional relationship between sleep disturbance and chronic pain; that is, impaired sleep may worsen chronic pain, and chronic pain causes sleep disturbance. However, more recent reviews and studies seem to show a more associative, rather than causative relationship. There have been recent studies that attempt to determine mechanisms that link sleep disturbance and chronic pain; the results of these studies were more varied, ultimately concluding that there may be a separate, yet-to-be discovered mechanism that shows the causative relationship between sleep disturbance and pain. There are several neurotransmitters that are involved in the mediation of chronic pain and sleep disturbance as separate entities, and some studies have shown that there may be mechanisms that govern both chronic pain and sleep disturbance as a single unit. Other neuroendocrine substances also serve to mediate chronic pain and sleep disturbance. All these substances are found to be associated with various sleep disorders and are also associated with chronic pain symptoms as well. Inflammation plays a role in chronic pain and sleep disturbance, with an increase in inflammatory substances and mediators associated with an increase or worsening in chronic pain symptoms and sleep disorders. The HPA axis plays a role in chronic pain and sleep disorders, influencing pain and sleep pathways through stress response, inflammation, and maintenance of homeostasis. There are several variables that influence both chronic pain and sleep disturbance, and more research into these variables may further our understanding into the complex pathways governing the influence of sleep disturbance on pain, and ultimately to improve treatment for this issue.

Electroacupuncture stimulation of HT7 alleviates sleep disruption following acute caffeine exposure by regulating BDNF-mediated endoplasmic reticulum stress in the rat medial septum

Acupuncture stimulation can protect the brain against caffeine-induced sleep disruption. This study investigated whether electroacupuncture stimulation acupuncture point HT7 alleviates sleep disruption by regulating mBDNF and ER stress in the medial septum. Acute exposure to caffeine (15 mg/kg, i.p.) increased the wake time and decreased REM sleep, which HT7 stimulation alleviated. HT7 stimulation ameliorated the acute caffeine exposure-induced increase in the expression of BiP, an endoplasmic reticulum stress response protein, in the rat medial septum. Interestingly, HT7 stimulation induced the expression of mBDNF and pTrkB in the medial septum. The next experiment investigated whether TrkB phosphorylated by HT7 stimulation induced BiP expression in the rat medial septum. Before electroacupuncture stimulation at HT7, ANA-12 was administered to caffeine-treated rats. In rats administered ANA-12 in the medial septum, HT7 stimulation did not reduce BiP expression. These findings suggest that HT7 stimulation improves wake time and REM sleep dysfunction by regulating the BDNF-mediated endoplasmic reticulum stress response in the medial septum. These results indicate that the alleviation of endoplasmic reticulum stress in the medial septum by HT7 stimulation and the subsequent amelioration of insomnia may depend on phosphorylated TrkB activation.

Sleep loss and addiction

Reducing sleep hours is a risk factor for developing cardiovascular, metabolic, and psychiatric disorders. Furthermore, previous studies have shown that reduction in sleep time is a factor that favors relapse in addicted patients. Additionally, animal models have demonstrated that both sleep restriction and sleep deprivation increase the preference for alcohol, methylphenidate, and the self-administration of cocaine. Therefore, the present review discusses current knowledge about the influence of sleep hours reduction on addictivebehaviors; likewise, we discuss the neuronal basis underlying the sleep reduction-addiction relationship, like the role of the orexin and dopaminergic system and neuronal plasticity (i.e., delta FosB expression). Potentially, chronic sleep restriction could increase brain vulnerability and promote addictive behavior.

Relationships between Sleep Duration, Timing, Consistency, and Chronotype with Myopia among School-Aged Children

Background

The role of sleep in childhood myopia has been a research focus; however, the existing evidence is conflicting on sleep duration and timing, and as yet, no studies involve sleep consistency and chronotype. This study is done to make multiple-perspective analyses on the associations between sleep variables and myopia.

Methods

A population-based cross-sectional study was conducted in Shanghai, China, which included 10,142 school-aged children (7–12 years old, 53.2% boys). The Chinese version of the Children's Sleep Habits Questionnaire (CSHQ) was used to assess sleep variables. Propensity score matching was adopted to balance the difference of covariates between nonmyopic and myopic groups. Logistic regression models were implemented to examine the associations between sleep variables and myopia.

Results

Sleep duration and timing, mainly during weekdays, were correlated with myopia in a dose-dependent pattern, in which longer sleep duration was associated with decreased risk of myopia (9-10 hours/day: odds ratio (OR) = 0.87; ≥10 hours/day: OR = 0.77; by comparison with <9 hours/day); later bedtime (9 pm to 9:30 pm: OR = 1.46; 9:30 pm to 10 pm: OR = 1.51; 10 pm and after: OR = 2.08; by comparison with before 9 pm) and later wake-up time (7 am and after: OR = 1.36; by comparison with before 6:30 am) increased the risk (all P < 0.05). Moreover, longer weekend catch-up sleep duration and intermediate and evening chronotype were positively correlated with myopia, while social jetlag was associated with a lower odds of myopia. All these findings were also similarly observed in the matching sample.

Conclusions

Multiple dimensions of sleep were involved in childhood myopia. In addition to sleep duration and timing, sleep consistency and chronotype were also strictly related to myopia. More studies are needed to enrich the current evidence, thus further clarifying the association between sleep and childhood myopia.

Cross talk mechanism of disturbed sleep patterns in neurological and psychological disorders

The incidence and prevalence of sleep disorders continue to increase in the elderly populace, particularly those suffering from neurodegenerative and neuropsychiatric disorders. This not only affects the quality of life but also accelerates the progression of the disease. There are many reasons behind sleep disturbances in such patients, for instance, medication use, nocturia, obesity, environmental factors, nocturnal motor disturbances and depressive symptoms. This review focuses on the mechanism and effects of sleep dysfunction in neurodegenerative and neuropsychiatric disorders. Wherein we discuss disturbed circadian rhythm, signaling cascade and regulation of genes during sleep deprivation. Moreover, we explain the perturbation in brainwaves during disturbed sleep and the ocular perspective of neurodegenerative and neuropsychiatric manifestations in sleep disorders. Further, as the pharmacological approach is often futile and carries side effects, therefore, the non-pharmacological approach opens newer possibilities to treat these disorders and widens the landscape of treatment options for patients.

The Prevalence and Progression of Myopia in Elementary School Students in Shanxi Province, China During the COVID-19 Pandemic

PURPOSE

To investigate the prevalence of myopia and the risk factors associated with its progression in elementary school students during the COVID-19 pandemic in Shanxi Province, China.

METHODS

The investigation included 960 students spanning first to sixth grade from six elementary schools in Shanxi Province, China. All participants received non-cycloplegic refraction and vision tests in December of 2019 (before the COVID-19 pandemic) and in June of 2020 (after classes resumed). Information concerning the students' eye-use behaviors, physical activities, diet and sleep during the pandemic was collected using a questionnaire survey. A total of 913 students (457 males) completed all tests and the questionnaire.

RESULTS

The overall prevalence rate of myopia was 16.6% in December of 2019, and it increased with age. There was no gender difference in the prevalence of myopia (χ² = 3.210, P = .073), but females exhibited a lower average spherical equivalent (SE) (P = .026). When the classes were resumed 6 months later, the overall prevalence rate of myopia was found to be 39.4%, which was significantly higher than it before the pandemic (χ² = 117.425, P < .001). The average SE of the participants was -0.95D, which was significantly lower than the average SE (-0.43D) before the pandemic (P < .001). SE variation (ΔSE) in grade 6 was significantly higher than that in grade 1. No significant difference in ΔSE was found between males and females. Analyses of ordinary least squares (OLS)-estimated linear, natural logarithmic and quadratic functions revealed that the progression of myopia during the COVID-19 pandemic was significantly correlated with screen time, types of electronic devices, the amount of sleep, age, and the number of parents with myopia.

CONCLUSIONS

The prevalence rate and progression of myopia among elementary school students in Shanxi Province increased significantly during the COVID-19 pandemic, which was likely related to China's home-based online learning programs. Therefore, it is necessary to optimize the educational programs for elementary school students when they study at home. We recommend increased time for outdoor activities and limiting screen time.

Historical and Modern Evidence for the Role of Reward Circuitry in Emergence

Increasing evidence supports a role for brain reward circuitry in modulating arousal along with emergence from anesthesia. Emergence remains an important frontier for investigation, since no drug exists in clinical practice to initiate rapid and smooth emergence. This review discusses clinical and preclinical evidence indicating a role for two brain regions classically considered integral components of the mesolimbic brain reward circuitry, the ventral tegmental area and the nucleus accumbens, in emergence from propofol and volatile anesthesia. Then there is a description of modern systems neuroscience approaches to neural circuit investigations that will help span the large gap between preclinical and clinical investigation with the shared aim of developing therapies to promote rapid emergence without agitation or delirium. This article proposes that neuroscientists include models of whole-brain network activity in future studies to inform the translational value of preclinical investigations and foster productive dialogues with clinician anesthesiologists.

Sleep Disturbance Alters Cocaine-Induced Locomotor Activity: Involvement of Striatal Neuroimmune and Dopamine Signaling

Sleep disorders have high comorbidity with drug addiction and function as major risk factors for developing drug addiction. Recent studies have indicated that both sleep disturbance (SD) and abused drugs could activate microglia, and that increased neuroinflammation plays a critical role in the pathogenesis of both diseases. Whether microglia are involved in the contribution of chronic SDs to drug addiction has never been explored. In this study, we employed a mouse model of sleep fragmentation (SF) with cocaine treatment and examined their locomotor activities, as well as neuroinflammation levels and dopamine signaling in the striatum, to assess their interaction. We also included mice with, or without, SF that underwent cocaine withdrawal and challenge. Our results showed that SF significantly blunted cocaine-induced locomotor stimulation while having marginal effects on locomotor activity of mice with saline injections. Meanwhile, SF modulated the effects of cocaine on neuroimmune signaling in the striatum and in ex vivo isolated microglia. We did not observe differences in dopamine signaling in the striatum among treatment groups. In mice exposed to cocaine and later withdrawal, SF reduced locomotor sensitivity and also modulated neuroimmune and dopamine signaling in the striatum. Taken together, our results suggested that SF was capable of blunting cocaine-induced psychoactive effects through modulating neuroimmune and dopamine signaling. We hypothesize that SF could affect neuroimmune and dopamine signaling in the brain reward circuitry, which might mediate the linkage between sleep disorders and drug addiction.

The Birth of the Mammalian Sleep

Simple Summary

Mammals evolved from reptiles as a consequence of an evolutionary bottleneck. Some diurnal reptiles extended their activity, first to twilight and then to the entire dark time. This forced the change of the visual system. Pursuing maximal sensitivity, they abandoned the filters protecting the eyes against the dangerous diurnal light, which, in turn, forced immobility in lightproof burrows during light time. This was the birth of the mammalian sleep. Then, the Cretacic-Paleogene extinction of dinosaurs leaved free the diurnal niche and allowed the expansion of a few early mammals to diurnal life and the high variability of sleep traits. On the other hand, we propose that the idling rest is a state showing homeostatic regulation. Therefore, the difference between behavioral rest and wakeful idling is rather low: both show quiescence, raised sensory thresholds, reversibility, specific sleeping-resting sites and body positions, it is a pleasing state, and both are dependent of circadian and homeostatic regulation. Indeed, the most important difference is the unconsciousness of sleep and the consciousness of wakeful idling. Thus, we propose that sleep is a mere upgrade of the wakeful rest, and both may have the same function: guaranteeing rest during a part of the daily cycle.

Abstract

Mammals evolved from small-sized reptiles that developed endothermic metabolism. This allowed filling the nocturnal niche. They traded-off visual acuity for sensitivity but became defenseless against the dangerous daylight. To avoid such danger, they rested with closed eyes in lightproof burrows during light-time. This was the birth of the mammalian sleep, the main finding of this report. Improved audition and olfaction counterweighed the visual impairments and facilitated the cortical development. This process is called “The Nocturnal Evolutionary Bottleneck”. Pre-mammals were nocturnal until the Cretacic-Paleogene extinction of dinosaurs. Some early mammals returned to diurnal activity, and this allowed the high variability in sleeping patterns observed today. The traits of Waking Idleness are almost identical to those of behavioral sleep, including homeostatic regulation. This is another important finding of this report. In summary, behavioral sleep seems to be an upgrade of Waking Idleness Indeed, the trait that never fails to show is quiescence. We conclude that the main function of sleep consists in guaranteeing it during a part of the daily cycle.

Poor Sleep in Community-Dwelling Polysubstance Users: Association With Khat Dependence, Metacognition, and Socio-Demographic Factors

Purpose

Poor sleep and cognitive deficits are often associated with increased drug use. However, no study has addressed the relationship between poor sleep, substance dependence, and metacognitive deficit in polysubstance users.

Methods

This was a cross-sectional study with a simple random sampling involving community-dwelling polysubstance users (n = 326, age = 18-43 years) in Mizan, Ethiopia. Participants completed a brief sleep questionnaire, severity of dependence on khat (SDS-Khat), a brief meta-cognition questionnaire, and a socio-demographic survey.

Results

Majority (56.4%) of the polysubstance users had sleep disturbance. Chronic health conditions [adjusted odds ratio (AOR) = 2.52, 95% confidence interval (CI) 1.31-4.85], chronic conditions in the family (AOR = 2.69, 95% CI 1.40-5.20), illiterate-primary level of educational status (AOR = 2.40, 95% CI 1.30-4.04), higher SDS-Khat score (AOR = 1.39, 95% CI 1.13-1.72), and lower meta-cognition score (AOR = 0.90, 95% CI 0.84-0.97) predicted poor sleep in the polysubstance users. Moreover, low metacognition score and high SDS score also predicted additional sleep disturbances like chronic sleep insufficiency, lethargy and restlessness after nighttime sleep, socio-occupational dysfunctions, and daytime disturbances in polysubstance users.

Conclusion

Poor sleep, severe khat dependence, and metacognitive deficits are common in community polysubstance users. Moreover, poor sleep is associated with higher khat dependence, lower metacognitive ability, lower educational status, and the presence of chronic conditions in polysubstance users or their families.

Objective Sleep-Wake Characteristics Are Associated With Diabetes Symptoms in Young Adults With Type 1 Diabetes

PURPOSE

The primary purpose of this descriptive cross-sectional study was to examine the associations between sleep-wake characteristics (total sleep time, sleep variability, sleep onset latency, and sleep efficiency), distress symptoms (general and diabetes), and diabetes physical symptoms in young adults ages 18 to 30 years with type 1 diabetes (T1D). The secondary purpose was to determine whether biological sex, body mass index (BMI), and T1D duration (covariates) influence the relationships among the study variables.

METHODS

Forty-six young adults with T1D, recruited from diabetes clinics from December 2018 to February 2020, wore a wrist actigraph and continuous glucose monitor concurrently for 6 to 14 days and completed the PROMIS Emotional Distress Scale, Diabetes Distress Scale, and Diabetes Symptom Checklist-Revised.

RESULTS

Shorter total sleep time and poorer sleep efficiency were associated with higher diabetes emotional distress symptoms. Higher sleep variability was associated with higher neurological pain symptoms. A longer sleep onset latency was associated with higher symptoms of diabetes distress, including psychological, cognitive, hyperglycemia, and a higher total symptom burden. Associations remained statistically significant after adjusting for biological sex and BMI, with the exception of sleep onset latency and total symptom burden.

CONCLUSIONS

Poorer objective sleep-wake characteristics were associated with higher diabetes symptoms even after considering biological sex and BMI among young adults with T1D.

The Mind After Midnight: Nocturnal Wakefulness, Behavioral Dysregulation, and Psychopathology

Sufficient sleep with minimal interruption during the circadian/biological night supports daytime cognition and emotional regulation. Conversely, disrupted sleep involving significant nocturnal wakefulness leads to cognitive and behavioral dysregulation. Most studies to-date have examined how fragmented or insufficient sleep affects next-day functioning, but recent work highlights changes in cognition and behavior that occur when someone is awake during the night. This review summarizes the evidence for day-night alterations in maladaptive behaviors, including suicide, violent crime, and substance use, and examines how mood, reward processing, and executive function differ during nocturnal wakefulness. Based on this evidence, we propose the Mind after Midnight hypothesis in which attentional biases, negative affect, altered reward processing, and prefrontal disinhibition interact to promote behavioral dysregulation and psychiatric disorders.

A Comprehensive Review of the Literature on Sleep Difficulties and Suicidality in Youth to Inform an Integrative Developmental Model and Future Directions

Purpose of Review

Suicide is currently the second leading cause of death among youth. Identification of modifiable near-term risk factors can inform suicide prevention strategies. One promising, readily assessed factor is sleep. We critically review the literature on sleep and suicidal thoughts and behaviors among youth.

Recent Findings

Most studies examining the youth sleep-suicidality relationship are from epidemiological samples in which both sleep problems and suicidality were assessed over variable timeframes using limited items from scales not designed to measure these constructs. Nonetheless, these data overwhelmingly support an association between suicidality and a range of sleep difficulties (e.g., insomnia, short/long sleep, weekend oversleep), above and beyond depressive symptoms. Limited studies include clinical samples or prospective designs. We review potential mechanisms and present a developmentally-informed integrative model.

Summary

Literature supports a clear association between sleep difficulties and youth suicidality. Future directions include prospective longitudinal studies and targeted prevention efforts.

The Effect of Improving Preoperative Sleep Quality on Perioperative Pain by Zolpidem in Patients Undergoing Laparoscopic Colorectal Surgery: A Prospective, Randomized Study

Methods

A prospective, randomized study was conducted with 88 patients undergoing laparoscopic colorectal surgery. The experimental group (S group, n = 44) was given 10 mg of zolpidem tartrate one night before the surgical procedure, while no medication was given to the control group (C group, n = 44). The primary outcome was the intraoperative remifentanil consumption. Sufentanil consumption, average patient-controlled analgesia (PCA) effective press times, the visual analog scale (VAS) scores, and incidences of postoperative nausea and vomiting (PONV) were recorded at 6 h (T1), 12 h (T2), and 24 h (T3) postoperatively.

Results

The intraoperative remifentanil consumption was significantly lower in the S group than that in the C group (p < 0.01). Sufentanil consumption at 6 h and 12 h postoperatively was significantly lower in the S group than that in the C group (p < 0.05); average PCA effective press times and VAS scores, at 6 h and 12 h postoperatively, were significantly lower in the S group than those in the C group (p < 0.01); differences between groups 24 h postoperatively were not significant. No significant between-group difference was noted in the incidence of nausea and vomiting.

Conclusion

Improving patients' sleep quality the night before surgical procedure by zolpidem can decrease the usage of intraoperative analgesics and reduce postoperative pain.

Etiologies of insomnia in Parkinson's disease - Lessons from human studies and animal models

Sleep disorders are integral to Parkinson's disease (PD). Insomnia, an inability to maintain stable sleep, affects most patients and is widely rated as one of the most debilitating facets of this disease. PD insomnia is often perceived as a multifactorial entity - a consequence of several of the disease symptoms, comorbidities and therapeutic strategies. Yet, this view evolved against a backdrop of a relative scarcity of works trying to directly dissect the underlying neural correlates and mechanisms in animal models. The last years have seen the emergence of a wealth of new evidence regarding the neural underpinnings of insomnia in PD. Here, we review early and recent reports from patients and animal models evaluating the etiology of PD insomnia. We start by outlining the phenomenology of PD insomnia and continue to analyze the evidence supporting insomnia as emanating from four distinct subdivisions of etiologies - the symptoms and comorbidities of the disease, the medical therapy, the degeneration of non-dopaminergic cell groups and subsequent alterations in circadian rhythms, and the degeneration of dopaminergic neurons in the brainstem and its resulting effect on the basal ganglia. Finally, we review emerging neuromodulation-based therapeutic avenues for PD insomnia.

Acute sleep deprivation immediately increases serum GDNF, BDNF and VEGF levels in healthy subjects

Acute sleep deprivation upregulates hippocampal neurogenesis. Neurotrophic factors such as glial cell line-derived neurotrophic factor (GDNF), brain-derived neurotrophic factor (BDNF), and vascular endothelial growth factor (VEGF) are mediators of neuronal plasticity and neurogenesis. These neurotrophins are involved in sleep and sleep disorders and are associated with sleep deprivation. In this study, it is aimed to investigate the changes of neurotrophin levels with total sleep deprivation in healthy individuals. Seventeen healthy young adults with a mean age of 19.8 (SD = 1.0) years underwent an experimental protocol consisting of 36 h of total sleep deprivation. Venous blood samples were obtained on Day1 at 09.00, on Day2 at 09.00, and at 21.00. Serum levels of neurotrophins were detected using the ELISA method. The participants were asked to mark the scores corresponding to their subjective energy, happiness, depression, tension levels on the visual analog scale; and sleepiness level on the Epworth Sleepiness Scale; during the course of the study. As a result of 36 h of sleep deprivation, serum GDNF, BDNF, and VEGF levels showed a statistically significant increase compared to the baseline values in the participants included in the study (P < 0.0001). While this increase was evident in 24 h, it continued after 36 h. In parallel, sleepiness levels, subjective depression, and tension levels increased, on the other hand, subjective energy and happiness scores decreased at a statistically significant level at the end of the study compared to basal values (P < 0.0001). The results show that acute sleep deprivation significantly affects and increases serum levels of neurotrophic factors, and it seems that these effects are likely to occur as an immediate response to the stress and disruption caused by sleep deprivation.