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We investigated how targeted reactivation of cortical memory engrams during sleep influences systems consolidation of contextual fear memory. Using a mouse model of contextual fear conditioning (CFC), we tagged retrosplenial cortex (RSC) neurons activated during learning with channelrhodopsin-2 (ChR2) via a c-Fos-based TRAP system. Twenty-four hours post-training, animals received optogenetic stimulation of these RSC engram cells selectively during non-rapid eye movement (NREM) sleep or REM sleep. Immediately after, hippocampal activity was transiently blocked (muscimol infusion) to test hippocampal dependence. We found that NREM-specific reactivation of RSC engrams preserved contextual fear recall despite hippocampal inactivation, whereas REM stimulation or no stimulation failed to rescue memory. These results indicate that engram reactivation during NREM accelerates the transfer of memory to cortical storage. We present high-level diagrams of experimental workflow and results, and report a timeline of revisions. Abbreviations and keywords are provided. This comprehensive revision addresses all reviewer comments and renders the manuscript submission-ready.

<b>Background:</b> Sleep deprivation is increasingly prevalent among young adults due to academic, occupational, and social demands, making them susceptible to circadian disruption. Executive functioning—encompassing working memory, inhibitory control, and cognitive flexibility is essential for academic and professional success. This meta-analysis quantifies the effect of sleep deprivation on executive functioning in healthy young adults. Practical Implications: These findings highlight the need for evidence-based interventions such as university-level sleep education programs, flexible academic scheduling, and workplace policies promoting adequate sleep to optimize cognitive performance and productivity among young adults. <b>Methods: </b>Following PRISMA 2020 guidelines, PubMed, Scopus, PsycINFO, and Web of Science were searched (January 2000–March 2024) for studies assessing acute (<6 hours sleep or ≥24 hours total deprivation) or chronic (<6 hours/night over multiple days) sleep deprivation in young adults. Outcomes included validated executive function tests (e.g., Stroop, N-Back). Random-effects meta-analysis (Hedges’ g) was conducted using R (version 4.3.2) with metafor/meta packages. Heterogeneity (I², Q-test), sensitivity (leave-one-out), and publication bias (funnel plot, Egger’s test) were evaluated. <b>Results: </b>Out of 2,478 screened studies, 39 met inclusion criteria (n=4,578). Sleep deprivation had a moderate-to-large detrimental effect on executive functioning (Hedges’ g = -0.62, 95% CI [-0.78, -0.45], p<0.001). Subdomain analysis revealed greatest impairment in working memory (g = -0.71), followed by inhibitory control (g = -0.59) and cognitive flexibility (g = -0.49) (all p<0.001). Moderate heterogeneity was present (I² = 58%), with results robust to sensitivity analysis. Egger’s test indicated no significant publication bias (p=0.22). <b>Interpretation</b><b>: </b>Sleep deprivation significantly impairs executive functioning in young adults, especially working memory. Interventions improve sleep may enhance cognitive performance and should be integrated into public health strategies and educational policies. Future research should assess chronic restriction and individual vulnerability factors.

Recent advancements in the screening, diagnosis, and management of obstructive sleep apnea (OSA) have significantly improved patient outcomes. For screening, the use of home sleep apnea testing (HSAT) has become more prevalent, offering a convenient and cost-effective alternative to traditional in-lab polysomnography. HSAT devices have shown good specificity and sensitivity, particularly in patients with a high pre-test probability of OSA. In terms of diagnosis, advancements in wearable technology and mobile health applications have enabled continuous monitoring of sleep patterns and respiratory parameters. These tools provide valuable data that can be used to identify OSA more accurately and promptly. Additionally, machine learning algorithms are being integrated into diagnostic processes to enhance the accuracy of OSA detection by analyzing large datasets and identifying patterns indicative of the condition. Management of OSA has also seen significant progress. Continuous positive airway pressure (CPAP) therapy remains the gold standard, but new developments include auto-adjusting CPAP devices that optimize pressure settings based on real-time feedback. Mandibular advancement devices and hypoglossal nerve stimulation are emerging as effective alternatives for patients who are CPAP-intolerant. Furthermore, lifestyle interventions such as weight management, positional therapy, and exercise have been shown to complement medical treatments, leading to better overall outcomes. This review article highlights these advancements that collectively contribute to improved patient adherence, reduced symptoms, and enhanced quality of life for individuals with OSA.

Antenatal and postpartum major depressive episode (MDE) according to Diagnostic and Statistical Manual of Mental Disorders 5th Edition (DSM-V) is defined as either daily sustained sad mood or lack of enjoyment or desire for a minimum two weeks plus four associated manifestations (only three if the two major symptoms are present) that start throughout pregnancy or during the first 4 weeks postpartum respectively: 1) Unintentional notable slimming up or down; 2) Sleepiness or sleeplessness; 3) Tiredness sensation; 4) Guilty or futility sensation; 5) Declined concentration capacity; 6) Frequent suicidal thoughts; 7) Psychomotor excitation or delay. Perinatal depression carries vital and adverse consequences on mother’s psychosocial aspects of life, pregnancy and delivery outcomes, her interrelations specifically with the new born with poorer overall health and influences negatively on offspring from the intrauterine life passing by complicated delivery experiencing hard unstable childhood reaching unhealthy adolescence and adulthood. These negative consequences necessitate a great attention for prevention, screening and prompt treatment for antenatal and postnatal depression to prevent such disastrous effects.

Proper and effective management of obstructive sleep apnea (OSA) in elderly patients represents an important yet under-researched therapeutic target. Therefore, the main purpose of our research was to employ age stratification to analyse sleep quality and sleep fragmentation, the daily sleepiness, OSA severity and CPAP compliance in elderly. Conforming to the inclusion criteria of minimum 70 years of age at the time of polysomnography and CPAP titration night a total number of 162 elderly patients was included, median age 73,00±4 (MED±IQR). The comparison group consisted of 448 adult subjects under the age of 70 years old, median age 54,00±14,00 (MED±IQR). Sleep fragmentation in elderly was promoted to suboptimal CPAP adherence, as the probability of CPAP use ≥ 4 hours per day was less than 20%. Overall CPAP compliance hours in the elderly group achieved 3,991±3,804 hours/day with bigger variation in between the subjects versus 5,547±3,465 hours/day for the controls, (MED±IQR, p<0,001). Despite naturally occurring sleep fragmentation worsened by OSA, less than 30% of elderly patients would score ≥ 10 points on Epworth sleepiness scale. The study emphasizes acute need for standardized age-specific diagnostic tools to address different perception of daily drowsiness and sleepiness by older people. Further, it underlines the importance of early recognition of possible comorbid OSA and insomnia and suggest paying more attention to “non-obese phenotype” in the subgroup of elderly patients with suspected OSA. Elderly patients might also need development of more flexible CPAP compliance criteria; however, those must be standardized and objective.<b> </b>