Sleep and memory: The impact of sleep deprivation on transcription, translational control, and protein synthesis in the brain

Sleep characteristics and brain structure: A systematic review with meta-analysis

BACKGROUND

As the global population ages, the prevalence of associated conditions, including neurodegeneration and dementia, will increase. Thus, reducing risk factors is crucial to prevention. Sleep contributes to brain homeostasis and repair, which, if impaired, could lead to neurodegeneration. However, the relationship between sleep characteristics, disorders, and brain morphology is poorly understood in healthy adults. Therefore, we aimed to systematically analyse the literature and clarify how sleep characteristics are associated with brain structures.

METHODS

We systematically searched PUBMED, MEDLINE, ProQuest, Web of Science, and Scopus for empirical studies of healthy adults examining the associations between sleep characteristics or disorders and brain structure, adjusting for age, gender, and head size. We conducted a meta-analysis with random effects models for volumetric studies and a seed-based spatial analysis for voxel-based morphometry (VBM) studies.

RESULTS

One hundred and five articles (60 volumetric, 45 VBM) with 106 studies reporting 108,364 participants were included. Most studies (73.1%) found sleep characteristics and disorders to be associated with predominantly lower brain volumes (cross-sectional: 51.9% of all cross-sectional; longitudinal: 45.5% of longitudinal). In VBM studies, REM sleep behaviour disorder was linked to lower grey matter volume in the right frontal gyrus (z-score = -3.617, 68 voxels, p-value = <0 0.001).

CONCLUSION

Sleep characteristics - poor quality, short or long sleep - and sleep disorders are predominantly associated with lower brain volumes, suggesting that inadequate sleep (short, long or poor quality) might contribute to neurodegeneration. This insight highlights the importance of monitoring, managing, and enforcing sleep health to prevent or mitigate potential neurodegenerative processes.

Therapeutic effects of resveratrol on memory deficits in offspring of sleep-deprived rats: Involvement of hippocampal BDNF-TrkB pathways

BACKGROUND

Maternal sleep deprivation (MSD) is a significant public health issue that adversely affects neurogenesis and synaptic plasticity in offspring, resulting in cognitive deficits in learning and memory. Resveratrol, an antioxidant with neuroprotective and anti-inflammatory properties, may help mitigate these effects. This study investigates resveratrol's potential to counteract the negative impacts of MSD on neurodevelopment in male Wistar rat offspring.

METHODS

Ninety-six male Wistar rat offspring and 36 pregnant rats were used. Total MSD was induced using the water box device on gestational days 7, 11, and 17. Pregnant rats received resveratrol at doses of 25 or 50 mg/kg every 12 h during the sleep deprivation period. After parturition, offspring were divided into 12 groups for assessment at two months of age. Social interaction tests evaluated social memory, while the Morris water maze test assessed spatial learning and memory. Brain samples were prepared for Nissl staining, and brain-derived neurotrophic factor (BDNF) and tyrosine-protein kinase (TrkB) expression levels in the hippocampus were measured using western blotting.

RESULTS

Our findings indicate that the MSD group exhibited decreased BDNF/TrkB expression and increased neuronal damage in the hippocampus, which led to disrupted spatial and social memory compared to the control group. Subsequently, resveratrol administration, especially at a dose of 50 mg/kg during pregnancy, significantly reversed MSD's detrimental effects on cognitive function in offspring.

CONCLUSION

Our results provide novel evidence of resveratrol's neuroprotective effects in rat pregnancy models of MSD, suggesting its potential for developing therapeutic interventions targeting prenatal neurodegenerative disorders.

Memory impairments observed after a half night sleep restriction are not mediated by working memory, attention, or inhibitory control mechanisms

Sleep restriction is a growing issue in our modern society and thus it is crucial to uncover its neurocognitive consequences. Especially declarative memory is negatively affected by sleep loss due to its critical dependence on the hippocampus, a brain area known to be susceptible to sleep loss. Studies have shown that even a half night sleep restriction is sufficient to induce impairments in a range of hippocampus-dependent forms of memory. Nevertheless, memory performance is, at least to some extent, dependent on other cognitive functions. The aim of the current study was to reveal whether memory deficits observed after one night sleep deprivation, as observed in animal studies, translate to man, and whether these effects are mediated by impairments in other cognitive domains. We hypothesized that the memory paradigms would be affected but that, due to the short nature of the sleep restriction, this effect would not be mediated by other cognitive functions. To this end, fifty-five healthy participants conducted a test battery containing paradigms measuring verbal learning, spatial memory, attention, working memory, and response inhibition after a night of regular sleep or acute partial sleep restriction. The results of the study showed an impairment in both hippocampus-dependent memory tests, while no negative consequences of sleep deprivation were revealed on the other cognitive domains. In conclusion, our data indicate that the observed deficit in memory performance after a half night sleep deprivation is not mediated by impairments in attention (alerting, orienting, and executive control), working memory, or motor inhibitory control mechanisms.

Sleep loss is a metabolic disorder

Sleep loss dysregulates cellular metabolism and energy homeostasis. Highly metabolically active cells, such as neurons, enter a catabolic state during periods of sleep loss, which consequently disrupts physiological functioning. Specific to the central nervous system, sleep loss results in impaired synaptogenesis and long-term memory, effects that are also characteristic of neurodegenerative diseases. In this review, we describe how sleep deprivation increases resting energy expenditure, leading to the development of a negative energy balance-a state with insufficient metabolic resources to support energy expenditure-in highly active cells like neurons. This disruption of energetic homeostasis alters the balance of metabolites, including adenosine, lactate, and lipid peroxides, such that energetically costly processes, such as synapse formation, are attenuated. During sleep loss, metabolically active cells shunt energetic resources away from those processes that are not acutely essential, like memory formation, to support cell survival. Ultimately, these findings characterize sleep loss as a metabolic disorder.

Preoperative Sleep Deprivation Exacerbates Anesthesia/Surgery-induced Abnormal GABAergic Neurotransmission and Neuronal Damage in the Hippocampus in Aged Mice

Older adults with anesthesia and surgery often suffer from postoperative cognitive dysfunction (POCD), which puts a heavy burden on rehabilitation. Preoperative sleep disorder, a common phenomenon in elderly anesthesia patients, is closely associated with POCD, but the underlying mechanism is still not fully understood. Hippocampal gamma-aminobutyric acid (GABA)ergic neurotransmission has been reported to play an important role in sleep disorder and cognitive impairment. The aim of this study was to elucidate the effect of preoperative acute sleep deprivation (SD) on anesthesia/surgery-induced POCD and the potential mechanism of hippocampal GABAergic neurotransmission. In the aged (18-20-month-old) male mice, we used a rotating rod to deprive sleep for 24 h and induced a POCD model using sevoflurane exposure combined with laparotomy exploration. A sequential set of behavioral tests, including open field test (OFT), Y-maze, and novel object recognition (NOR), was conducted to assess cognitive performances. In vivo magnetic resonance imaging (MRI) technique was used to observe hippocampal axonal microstructural changes. The levels of GABAergic neurotransmitter markers glutamic acid decarboxylase (GAD) 67, vesicular GABA transporter (VGAT), GABA transporter (GAT)-1, and GABA in the hippocampus were detected with enzyme-linked immunosorbent assay (ELISA). The reactivity of GABAergic neurons and neuronal damage in different subregions of the hippocampus were observed by immunofluorescence and Nissl staining, respectively. Compared the anesthesia/surgery (A/S) mice, 24-h SD combined with A/S induced shorter stay time in the central area of the open field, less the percent of novel arm preference in the Y maze, and lower recognition index in the NOR, as well as significantly enhanced hippocampal GABAergic neurotransmission, decreased hippocampal axonal integrity and density, and increased GAD67 reactivity and reduced the number of neurons in hippocampal CA1. Preoperative 24-h SD exacerbated anesthesia/surgery-induced POCD in aged mice, with the cumulative effect of abnormal GABAergic neurotransmission and neuronal damage in the hippocampus.

Melatonin Pattern: A New Method for Machine Learning-Based Classification of Sleep Deprivation

Background: Pattern recognition and machine learning-based classification approaches are frequently used, especially in the health field. In this research, a new feature extraction model inspired by the melatonin hormone (sleep hormone) and named MelPat (melatonin pattern) has been developed. The developed model has been tested on an open access dataset. Materials and Methods: An open access sleep deprivation electroencephalography (EEG) dataset was tested to evaluate the MelPat method. There are two classes in the dataset. These are (a) sleep deprivation (SD) and (b) healthy control (HC) groups, respectively. In this study, EEG signals were divided into 15 s segments, thus obtaining 1377 SD and 1378 HC samples. In the next phase of the research, a new feature extraction model was proposed, and this model was named MelPat as it was inspired by the melatonin hormone. Additionally, the feature vector was expanded using the statistical moment approach. In the signal decomposition phase of the model, the Tunable Q-Wavelet Transform (TQWT) method was used. Thus, the signal was decomposed into sub-bands, and feature extraction was applied to each band. Neighborhood Component Analysis (NCA) and Chi2 methods were used together to reduce the dimension of the feature vector and select the most significant features. In this phase, the most significant features from both feature selection algorithms were combined, and the final feature vector was obtained. In the classification phase of the model, the Support Vector Machine (SVM) algorithm, which is a shallow classifier, was used. The dataset used in the research has 61 channels. Therefore, after obtaining channel-based results, the iterative majority voting (IMV) algorithm was applied to achieve higher classification performance and generalize the results, and the most accurate results were automatically selected. Results: With the proposed MelPat algorithm, a high classification success of 97.71% was achieved on the open access sleep deprivation dataset. Conclusions: The obtained results show that the MelPat-based new classification approach is highly effective on the dataset collected for SD detection. Moreover, the fact that the proposed method is inspired by the melatonin chemical, which is the sleep hormone, makes the method attractive and ironic.

Age-Specific Functional Connectivity Changes After Partial Sleep Deprivation Are Correlated With Neurocognitive and Molecular Signatures

BACKGROUND

This study aimed to investigate age-specific alterations in functional connectivity after sleep deprivation (SD) and decode brain functional changes from neurocognitive and transcriptomic perspectives.

METHODS

Here, we examined changes in global and regional graph measures, particularly regional network strength (RNS), in 41 young participants and 36 older participants with normal sleep and after 3 h of SD. Additionally, by utilizing cognitive probabilistic maps from Neurosynth and gene expression data from the Allen Human Brain Atlas, we applied partial least-squares regression analysis to identify the neurocognitive and transcriptional correlates of these RNS changes.

RESULTS

After SD, older participants exhibited decreased RNS in the default mode network (DMN) and dorsal attention network, with increased RNS in the visual network. Young participants also showed decreased RNS in the DMN, notably in the left inferior parietal lobe, left dorsolateral prefrontal cortex, and left posterior cingulate cortex. In young participants, SD-induced RNS changes significantly correlated with cognitive processes such as "attention," "cognitive control," and "working memory," while in older participants, they correlated with "learning," "focus," and "decision." Gene-category enrichment analysis indicated that specific genes related to signal transduction, ion channels, and immune signaling might influence SD pathophysiology by affecting functional connectivity in young participants.

CONCLUSIONS

This study elucidates shared and age-specific brain functional network alterations associated with SD, providing a neurocognitive and molecular basis for understanding the underlying pathophysiology.

At least 150 min per week of Tai chi practice improves sleep quality in the older people: evidence from a meta-analysis

OBJECTIVE

To conduct a meta-analysis to explore the optimal dosage of Tai chi exercise that positively influences the sleep quality of the older people.

METHODS

A literature search was conducted from 2004 to October 2024 in PubMed, Embase, Web of Science, Google Scholar, Cochrane Library, and Chinese databases (CNKI and Wanfang) for randomised controlled trials in Chinese and English on Tai chi improving sleep quality in the older people. Data extraction and verification were performed by two independent researchers. Additionally, a meta-analysis of the mean difference (MD) and 95% confidence interval (CI) was conducted using RevMan 5.4.

RESULTS

A total of nine randomised controlled trials involving 1,166 older participants were included. Compared with the control group, Tai chi significantly reduced the total Pittsburgh Sleep Quality Index (PSQI) scores in the older people [MD =  - 1.53, 95% CI (- 2.18, - 0.89), p < 0.001], with heterogeneity results Q = 53.63, df = 12, and I2 of 78% (p < 0.001); Total weekly duration of Tai chi exercise: Less than 150 min reduced PSQI scores, but the difference was not statistically significant [MD =  - 1.47, 95% CI (- 3.89, 0.95), p = 0.23]. Between 150-300 min significantly reduced PSQI scores [MD =  - 1.54, 95% CI (- 2.00, - 1.08), p < 0.001]; Duration of Tai chi exercise programme: 8-12 weeks significantly reduced PSQI scores [MD =  - 1.93, 95% CI (- 2.60, - 1.25), p < 0.001]; 16-24 weeks significantly reduced PSQI scores [MD =  - 1.27, 95% CI (- 2.27, - 0.26), p = 0.01]; Single session duration of Tai chi exercise: 60 min significantly reduced PSQI scores [MD =  - 2.17, 95% CI (- 3.15, - 1.18), p < 0.001]; Less than 60 min (25-45 min) significantly reduced PSQI scores [MD =  - 0.92, 95% CI (- 1.63, - 0.20), p = 0.01].

CONCLUSION

Older individuals engaging in at least 150 min per week of Tai chi practice can improve sleep quality. Beyond this threshold, extending the duration of individual practice sessions or the exercise programme does not yield additional benefits for sleep quality.

WuYou decoction effectively reduces neuronal damage, synaptic dysfunction, and Aβ production in rats exposed to chronic sleep deprivation by modulating the Aβ-related enzymes and SIRT1/Nrf2/NF-κB pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Chronic sleep deprivation (CSD) can result in neuronal damage, synaptic dysfunction, Aβ production, neuroinflammation, and ultimately cognitive deterioration. WuYou Decoction (WYD), a contemporary prescription, has shown promise in enhancing sleep quality and cognitive performance in individuals with insomnia. However, the specific molecular mechanisms responsible for the neuroprotective effects of WYD on CSD remain incompletely understood.

AIM OF THE STUDY

This study aimed to investigate the neuroprotective effects of WYD on the CSD model and its molecular mechanism.

MATERIALS AND METHODS

UHPLC-MS/MS analysis was utilized to analyze the active ingredients of WYD extract. The study employed the multi-platform water environment method to establish the CSD model in rats. Subsequent to treatment with varying doses of WYD in CSD rats, cognitive function and pathological alterations in hippocampus and cortex, including neuronal damage, synaptic dysfunction, Aβ production, and neuroinflammation, were evaluated through a combination of Morris Water Maze test, HE staining, Nissl staining, Golgi-Cox staining, Transmission electron microscope, ELISA, Immunohistochemistry staining, Immunofluorescence staining and Western blot.

RESULTS

UHPLC-MS/MS analysis revealed a total of 99 active ingredients were identified from the WYD extract. The administration of WYD exhibited a mitigation of cognitive decline in the model of CSD, as evidenced by increased neuron count in the hippocampus and cortex, and improved density and length of dendritic spines in these brain regions. Furthermore, WYD was found to suppress the Aβ production, and inhibit the expression of BACE1, PS1, GFAP, IBA1, IL-1β, IL-6, TNF-α, phosphorylated IκBα (Ser32) and phosphorylated NF-κB p65 (Ser536) in the hippocampus and cortex, while also increasing the levels of PSD95, SYN1, ADAM10, IDE, SIRT1 and Nrf2.

CONCLUSIONS

WYD exhibits neuroprotective properties in CSD, potentially through modulation of the Aβ-related enzymes and SIRT1/Nrf2/NF-κB pathway.

Triphala ameliorates cognitive deficits and anxiety via activation of the Nrf2/HO-1 axis in chronic sleep-deprived mice

Triphala is renowned for its curative attributes and has been utilized for centuries to address diverse health ailments. Moreover, the active component of Triphala, polyphenols, is widely recognized for its excellent pharmacological activities, such as anti-inflammatory properties, and has been utilized as a potential natural remedy. However, the precise mechanism through which Triphala alleviates cognitive dysfunction and anxiety induced by chronic sleep deprivation (SD) remains restricted. The objective of this investigation is to examine and clarify the potential mechanism of action that underlies the therapeutic benefits of Triphala in addressing cognitive dysfunction and anxiety induced by chronic SD. Our results demonstrated that Triphala significantly alleviates chronic SD-induced behavioral abnormalities. Additionally, Triphala was highly effective at preventing histopathological or morphological damage to neurons located in the hippocampus. The therapeutic effects of Triphala in treating cognitive dysfunction and anxiety induced by chronic SD involve the modulation of several biological pathways, including inflammation and immune responses, oxidative stress, cell growth and differentiation, metabolism, and neurotransmitter communication. Moreover, our study illustrated that Triphala increased the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and significantly activated the Nrf2/hemeoxygenase-1 (HO-1) axis. Additionally, the neuroprotective properties of Triphala were found to be counteracted by the Nrf2 inhibitor ML385. Our study represented the first to unveil that Triphala exerts therapeutic benefits in alleviating chronic SD-induced cognitive deficits and anxiety by activation of the Nrf2/HO-1 axis. Triphala emerges as a promising nutraceutical ingredient for mitigating cognitive deficits and anxiety linked to chronic SD.

Effects of insomnia treatments on cognitive function: A meta-analysis of randomized controlled trials

BACKGROUND

Globally, insomnia has been shown to impact cognitive function, which has prompted the exploration of effective treatments to enhance cognitive outcomes. Both pharmacological and non-pharmacological interventions vary in their effects, indicating that further research for optimized therapeutic strategies is needed.

METHODS

Searches of PubMed, EMBASE, Web of Science, the Cochrane Library, and PsychInfo from database inception until August 2024 were conducted to identify relevant randomized controlled studies investigating the impacts of insomnia treatments on cognitive function. The standardized mean difference (SMD) and 95% confidence interval (CI) were calculated for all studies. Sensitivity analysis, publication bias, and meta-regression were performed.

RESULTS

A total of 14,829 records were retrieved, with 24 randomized controlled studies assessing the impact of insomnia treatment on cognition. Pooled analysis indicated that non-pharmacological interventions significantly enhanced cognitive function (SMD: 0.27, 95% CI: 0.04-0.49, p = 0.019), with notable improvements observed in memory (SMD: 1.18, 95% CI: 0.25-2.12, p = 0.013), attention (SMD: 0.32, 95% CI: 0.15-0.50, p < 0.001), and daily living activities (SMD: 0.29, 95% CI: 0.20-0.39, p < 0.001) based on self-reported measures. Longer follow-up periods were associated with more pronounced cognitive benefits (SMD: 0.34, 95% CI: 0.14-0.54, p = 0.001).

CONCLUSIONS

The critical role of insomnia treatments, particularly non-pharmacological interventions, in improving cognitive function is highlighted, emphasizing the importance of tailored therapeutic approaches to optimize cognitive outcomes and overall well-being.

ChatGPT vs. sleep disorder specialist responses to common sleep queries: Ratings by experts and laypeople

BACKGROUND

Many individuals use the Internet, including generative artificial intelligence like ChatGPT, for sleep-related information before consulting medical professionals. This study compared responses from sleep disorder specialists and ChatGPT to common sleep queries, with experts and laypersons evaluating the responses' accuracy and clarity.

METHODS

We assessed responses from sleep medicine specialists and ChatGPT-4 to 140 sleep-related questions from the Korean Sleep Research Society's website. In a blinded study design, sleep disorder experts and laypersons rated the medical helpfulness, emotional supportiveness, and sentence comprehensibility of the responses on a 1-5 scale.

RESULTS

Laypersons rated ChatGPT higher for medical helpfulness (3.79 ± 0.90 vs. 3.44 ± 0.99, p < .001), emotional supportiveness (3.48 ± 0.79 vs. 3.12 ± 0.98, p < .001), and sentence comprehensibility (4.24 ± 0.79 vs. 4.14 ± 0.96, p = .028). Experts also rated ChatGPT higher for emotional supportiveness (3.33 ± 0.62 vs. 3.01 ± 0.67, p < .001) but preferred specialists' responses for sentence comprehensibility (4.15 ± 0.74 vs. 3.94 ± 0.90, p < .001). When it comes to medical helpfulness, the experts rated the specialists' answers slightly higher than the laypersons did (3.70 ± 0.84 vs. 3.63 ± 0.87, p = .109). Experts slightly preferred specialist responses overall (56.0%), while laypersons favored ChatGPT (54.3%; p < .001). ChatGPT's responses were significantly longer (186.76 ± 39.04 vs. 113.16 ± 95.77 words, p < .001).

DISCUSSION

Generative artificial intelligence like ChatGPT may help disseminate sleep-related medical information online. Laypersons appear to prefer ChatGPT's detailed, emotionally supportive responses over those from sleep disorder specialists.

Associations between the multitrajectory neuroplasticity of neuronavigated rTMS-mediated angular gyrus networks and brain gene expression in AD spectrum patients with sleep disorders

INTRODUCTION

The multifactorial influence of repetitive transcranial magnetic stimulation (rTMS) on neuroplasticity in neural networks is associated with improvements in cognitive dysfunction and sleep disorders. The mechanisms of rTMS and the transcriptional-neuronal correlation in Alzheimer's disease (AD) patients with sleep disorders have not been fully elucidated.

METHODS

Forty-six elderly participants with cognitive impairment (23 patients with low sleep quality and 23 patients with high sleep quality) underwent 4-week periods of neuronavigated rTMS of the angular gyrus and neuroimaging tests, and gene expression data for six post mortem brains were collected from another database. Transcription-neuroimaging association analysis was used to evaluate the effects on cognitive dysfunction and the underlying biological mechanisms involved.

RESULTS

Distinct variable neuroplasticity in the anterior and posterior angular gyrus networks was detected in the low sleep quality group. These interactions were associated with multiple gene pathways, and the comprehensive effects were associated with improvements in episodic memory.

DISCUSSION

Multitrajectory neuroplasticity is associated with complex biological mechanisms in AD-spectrum patients with sleep disorders.

HIGHLIGHTS

This was the first transcription-neuroimaging study to demonstrate that multitrajectory neuroplasticity in neural circuits was induced via neuronavigated rTMS, which was associated with complex gene expression in AD-spectrum patients with sleep disorders. The interactions between sleep quality and neuronavigated rTMS were coupled with multiple gene pathways and improvements in episodic memory. The present strategy for integrating neuroimaging, rTMS intervention, and genetic data provide a new approach to comprehending the biological mechanisms involved in AD.

Sleep and periodontal health

Sleep is fundamental for health and well-being. An adequate amount and quality of sleep is a cardinal component of a healthy lifestyle at the basis of the prevention of many non-communicable chronic diseases. Recent evidence suggests that sleep disorders, particularly obstructive sleep apnea, represent an emerging risk factor for periodontal health. This review article provides a critical appraisal of the existing literature concerning the association between sleep duration, sleep quality, sleep disorders in general, and obstructive sleep apnea with periodontal diseases, including gingivitis and periodontitis. The putative mechanisms underlying these associations are described as well as the potential clinical implications for diagnosis and treatment.

A global transcriptional atlas of the effect of acute sleep deprivation in the mouse frontal cortex

Sleep deprivation (SD) has negative effects on brain and body function. Sleep problems are prevalent in a variety of disorders, including neurodevelopmental and psychiatric conditions. Thus, understanding the molecular consequences of SD is of fundamental importance in biology. In this study, we present the first simultaneous bulk and single-nuclear RNA sequencing characterization of the effects of SD in the male mouse frontal cortex. We show that SD predominantly affects glutamatergic neurons, specifically in layers 4 and 5, and produces isoform switching of over 1500 genes, particularly those involved in splicing and RNA binding. At both the global and cell-type specific level, SD has a large repressive effect on transcription, downregulating thousands of genes and transcripts. As a resource we provide extensive characterizations of cell-types, genes, transcripts, and pathways affected by SD. We also provide publicly available tutorials aimed at allowing readers adapt analyses performed in this study to their own datasets.

The effect of modified Qiyuan paste on mice with low immunity and sleep deprivation by regulating GABA nerve and immune system

BACKGROUND

Low immunity and sleep disorders are prevalent suboptimal health conditions in contemporary populations, which render them susceptible to the infiltration of pathogenic factors. LJC, which has a long history in traditional Chinese medicine for nourishing the Yin and blood and calming the mind, is obtained by modifying Qiyuan paste. Dendrobium officinale Kimura et Migo has been shown to improve the immune function in sleep-deprived mice. In this study, based on the traditional Chinese medicine theory, LJC was prepared by adding D. officinale Kimura et Migo to Qiyuan paste decoction.

METHODS

Indicators of Yin deficiency syndrome, such as back temperature and grip strength, were measured in each group of mice; furthermore, behavioral tests and pentobarbital sodium-induced sleep tests were performed. An automatic biochemical analyzer, enzyme-linked immunosorbent assay kit, and other methods were used to determine routine blood parameters, serum immunoglobulin (IgG, IgA, and IgM), cont (C3, C4), acid phosphatase (ACP) and lactate dehydrogenase (LDH) levels in the spleen, serum hemolysin, and delayed-type hypersensitivity (DTH) levels. In addition, serum levels of γ-aminobutyric acid (GABA) and glutamate (Glu) were detected using high-performance liquid chromatography (HPLC). Hematoxylin-eosin staining and Nissl staining were used to assess the histological alterations in the hypothalamus tissue. Western blot and immunohistochemistry were used to detect the expressions of the GABA pathway proteins GABRA1, GAD, GAT1, and GABAT1 and those of CD4+ and CD8+ proteins in the thymus and spleen tissues.

RESULTS

The findings indicated that LJC prolonged the sleep duration, improved the pathological changes in the hippocampus, effectively upregulated the GABA content in the serum of mice, downregulated the Glu content and Glu/GABA ratio, enhanced the expressions of GABRA1, GAT1, and GAD, and decreased the expression of GABAT1 to assuage sleep disorders. Importantly, LJC alleviated the damage to the thymus and spleen tissues in the model mice and enhanced the activities of ACP and LDH in the spleen of the immunocompromised mice. Moreover, serum hemolysin levels and serum IgG, IgA, and IgM levels increased after LJC administration, which manifested as increased CD4+ content, decreased CD8+ content, and enhanced DTH response. In addition, LJC significantly increased the levels of complement C3 and C4, increased the number of white blood cells and lymphocytes, and decreased the percentage of neutrophils in the blood.

CONCLUSIONS

LJC can lead to improvements in immunocompromised mice models with insufficient sleep. The underlying mechanism may involve regulation of the GABA/Glu content and the expression levels of GABA metabolism pathway-related proteins in the brain of mice, enhancing their specific and nonspecific immune functions.

Translating and establishing the psychometric properties of the Jenkins Sleep Scale for Arabic-speaking individuals

BACKGROUND

The Jenkins Sleep Scale is a widely used self-report questionnaire that assesses sleep quality and disturbances. This study aimed to translate the scale into Arabic and evaluate its psychometric properties in an Arabic-speaking population.

METHODS

The Jenkins Sleep Scale was translated into Arabic using forward and backward translation procedures. The Arabic version was administered to a convenience sample of 420 adults along with the Pittsburgh Sleep Quality Index (PSQI) and Athens Insomnia Scale (AIS) for validation purposes. Reliability was examined using Cronbach's alpha and McDonald's omega coefficients. Confirmatory factor analysis (CFA) was also conducted to test the unidimensional factor structure. Convergent validity was assessed using correlations with PSQI and AIS scores.

RESULTS

The Cronbach's alpha and McDonald's omega values for the Arabic Jenkins Sleep Scale were 0.74 and 0.75, respectively, indicating good internal consistency. The 2-week and 4-week test-retest intraclass correlation coefficients were both 0.94 (p < 0.001), indicating excellent test-retest reliability. The CFA results confirmed the unidimensional factor structure (CFI = 0.99, TLI = 0.96, RMSEA = 0.08). The measurement model had an equivalent factor structure, loadings, intercepts, and residuals across sex, age, and marital status. Significant positive correlations were found between the Arabic Jenkins scale score and the PSQI (r = 0.80, p < 0.001) and AIS (r = 0.74, p < 0.001), supporting convergent validity.

CONCLUSION

The Arabic version of the Jenkins Sleep Scale demonstrated good psychometric properties. The findings support its use as a valid and reliable measure for evaluating sleep quality and disturbances among Arabic-speaking populations.

Role of Post-Transcriptional Regulation in Learning and Memory in Mammals

After many decades, during which most molecular studies on the regulation of gene expression focused on transcriptional events, it was realized that post-transcriptional control was equally important in order to determine where and when specific proteins were to be synthesized. Translational regulation is of the most importance in the brain, where all the steps of mRNA maturation, transport to different regions of the cells and actual expression, in response to specific signals, constitute the molecular basis for neuronal plasticity and, as a consequence, for structural stabilization/modification of synapses; notably, these latter events are fundamental for the highest brain functions, such as learning and memory, and are characterized by long-term potentiation (LTP) of specific synapses. Here, we will discuss the molecular bases of these fundamental events by considering both the role of RNA-binding proteins (RBPs) and the effects of non-coding RNAs involved in controlling splicing, editing, stability and translation of mRNAs. Importantly, it has also been found that dysregulation of mRNA metabolism/localization is involved in many pathological conditions, arising either during brain development or in the adult nervous system.

Treatment with the selective PDE4B inhibitor A-33 or PDE4D inhibitor zatolmilast prevents sleep deprivation-induced deficits in spatial pattern separation

Sleep deprivation (SD) disrupts hippocampus-dependent memory, particularly in the dentate gyrus (DG) region, an area crucial for pattern separation. Previous research showed that non-selective phosphodiesterase type 4 (PDE4) inhibitors like roflumilast can alleviate these deficits. However, it remains unclear whether these outcomes are specific to a particular subfamily of PDE4. Hence, this study examined the specific impact of PDE4B inhibitor (A-33) and PDE4D inhibitor (zatolmilast) on spatial pattern separation in sleep deprived mice. Results demonstrated that SD impairs pattern separation, but both zatolmilast and A-33 alleviate these effects. However, A-33 impaired pattern separation in non-sleep deprived animals. The cognitive benefits of these inhibitors after SD may arise from alterations in relevant signaling pathways in the DG. This study provides initial evidence that inhibiting PDE4B or PDE4D holds promise for mitigating memory deficits due to SD.

Systematic Metabolic Profiling of Mice with Sleep-Deprivation

Adequate sleep is essential for the biological maintenance of physical energy. Lack of sleep can affect thinking, lead to emotional anxiety, reduce immunity, and interfere with endocrine and metabolic processes, leading to disease. Previous studies have focused on long-term sleep deprivation and the risk of cancer, heart disease, diabetes, and obesity. However, systematic metabolomics analyses of blood, heart, liver, spleen, kidney, brown adipose tissue, and fecal granules have not been performed. This study aims to systematically assess the metabolic changes in the target organs caused by sleep deprivation in vivo, to search for differential metabolites and the involved metabolic pathways, to further understand the impact of sleep deprivation on health, and to provide strong evidence for the need for early intervention.

Genes Associated with Altered Brain Structure and Function in Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) has been widely reported to cause abnormalities in brain structure and function, but the genetic mechanisms behind these changes remain largely unexplored. Our research aims to investigate the relationship between sleep characteristics, cognitive impairments, genetic factors, and brain structure and function in OSA. Using structural and resting-state functional magnetic resonance imaging data, we compared cortical morphology and spontaneous brain activity between 28 patients with moderate-to-severe OSA and 34 healthy controls (HCs) utilizing voxel-based morphology (VBM) and the amplitude of low-frequency fluctuations (ALFF) analyses. In conjunction with the Allen Human Brain Atlas, we used transcriptome-neuroimaging spatial correlation analyses to investigate gene expression patterns associated with changes in gray matter volume (GMV) and ALFF in OSA. Compared to the HCs, the OSA group exhibited increased ALFF values in the left hippocampus (t = 5.294), amygdala (t = 4.176), caudate (t = 4.659), cerebellum (t = 5.896), and decreased ALFF values in the left precuneus (t = -4.776). VBM analysis revealed increased GMV in the right inferior parietal lobe (t = 5.158) in OSA. Additionally, functional enrichment analysis revealed that genes associated with both ALFF and GMV cross-sampling were enriched in gated channel activity and synaptic transmission, glutamatergic synapse, and neuron.

A Global Transcriptional Atlas of the Effect of Sleep Deprivation in the Mouse Frontal Cortex

Sleep deprivation (SD) has negative effects on brain function. Sleep problems are prevalent in neurodevelopmental, neurodegenerative and psychiatric disorders. Thus, understanding the molecular consequences of SD is of fundamental importance in neuroscience. In this study, we present the first simultaneous bulk and single-nuclear (sn)RNA sequencing characterization of the effects of SD in the mouse frontal cortex. We show that SD predominantly affects glutamatergic neurons, specifically in layers 4 and 5, and produces isoform switching of thousands of transcripts. At both the global and cell-type specific level, SD has a large repressive effect on transcription, down-regulating thousands of genes and transcripts; underscoring the importance of accounting for the effects of sleep loss in transcriptome studies of brain function. As a resource we provide extensive characterizations of cell types, genes, transcripts and pathways affected by SD; as well as tutorials for data analysis.

Acute sleep loss impairs object but not spatial pattern separation in humans

Pattern separation allows us to form discrete representations of information in memory. Pattern separation can be measured in several domains including spatial and object-based discrimination. The brain area largely involved in this process is the dentate gyrus of the hippocampus, which has been shown to be particularly sensitive to the effects of sleep loss. However, methodology in rodent and human studies varies greatly making translational conclusions difficult. Therefore, the aim of the current study was to measure the effects of sleep deprivation on human hippocampal function, using well-validated spatial and object-based pattern separation tests. The effects of acute sleep loss were examined, as this method is frequently used in rodent research but not human studies. Results show that sleep loss impaired performance on the object-based version of the test, but not spatial pattern separation. The findings support the notion that these discrimination projections represent separate but complimentary hippocampal processes, and further elucidates how they may be discretely affected by acute sleep loss.

Preface: Special issue "Brain Proteostasis in Health and Disease"

This preface introduces the Journal of Neurochemistry Special Issue on Brain Proteostasis. Adequate control of protein homeostasis, or proteostasis, has been at the center stage of brain physiology, and its deregulation may contribute to brain diseases, including several neuropsychiatric and neurodegenerative conditions. Therefore, delineating the processes underlying protein synthesis, folding, stability, function, and degradation in brain cells is key to promoting brain function and identifying effective therapeutic options for neurological disorders. This special issue comprises four review articles and four original articles covering the roles of protein homeostasis in several mechanisms that are of relevance to sleep, depression, stroke, dementia, and COVID-19. Thus, these articles highlight different aspects of proteostasis regulation in the brain and present important evidence on this growing and exciting field.

Cordycepin buffers anisomycin-induced fear memory deficit by restoring hippocampal BDNF

The process of memory consolidation involves the synthesis of new proteins, and interfering with protein synthesis through anisomycin can impair memory. Memory deficits due to aging and sleep disorders may also result from a reduction in protein synthesis. Rescuing memory deficits caused by protein synthesis deficiency is therefore an important issue that needs to be addressed. Our study focused on the effects of cordycepin on fear memory deficits induced by anisomycin using contextual fear conditioning. We observed that cordycepin was able to attenuate these deficits and restore BDNF levels in the hippocampus. The behavioral effects of cordycepin were dependent on the BDNF/TrkB pathway, as demonstrated by the use of ANA-12. Cordycepin had no significant impact on locomotor activity, anxiety or fear memory. Our findings provide the first evidence that cordycepin can prevent anisomycin-induced memory deficits by regulating BDNF expression in the hippocampus.