Rapid Eye Movement Research Articles

Metoclopramide-induced opsoclonus-myoclonus-ataxia syndrome: A rare side-effect

Opsoclonus-myoclonus-ataxia syndrome (OMAS) is an autoimmune disorder involving the nervous system characterized by rapid involuntary eye movements (opsoclonus), involuntary brief muscle twitching (myoclonus), loss of coordination of movements, imbalance, disturbances of sleep, irritability, slurring of speech, and decreases muscle tone. Hyperemesis gravidarum, intractable vomiting during pregnancy, results in reduction in intravascular volume, can produce ketonemia. We describe a case of primigravida who had hyperemesis gravidarum and suffered metoclopramide-induced OMAS.

Effects of Fragmentation of Stage 3 Sleep and Rapid Eye Movement Sleep on Melatonin Secretion

Effects of Fragmentation of Stage 3 Sleep and Rapid Eye Movement Sleep on Melatonin Secretion

Daily Life Experiences of People with Dementia with Lewy Bodies: A Qualitative Study

Dementia with Lewy bodies (DLB) is the second most common cause of dementia and is associated with unique difficulties due to its characteristic symptoms. This study aimed to identify daily life changes experienced by people with DLB due to characteristic symptoms other than visual hallucinations. Semi-structured interviews and content analyses were conducted on 13 people with DLB and their 17 family members. Qualitative content analysis identified three categories of difficulties experienced by people with DLB in daily life: body discomfort, obstacles in daily life, and psychological pain. Participants experienced not only physical changes due to symptoms such as cognitive fluctuations, parkinsonism, and rapid eye movement sleep behavior disorder but also psychological pain related to daily life difficulties. This suggests the need for care that appreciates the unique experiences of people with DLB and includes psychological care to develop appropriate individual coping strategies, rather than focusing solely on alleviating physical symptoms.

Alterations in the DTI-ALPS index and choroid plexus volume are associated with clinical symptoms in participants with narcolepsy type 1

BackgroundNarcolepsy type 1 (NT1) is a sleep disorder characterized by excessive daytime sleepiness accompanied by cataplexy. Sleep disorders have been shown to affect the glymphatic system. This study aimed to evaluate changes in the diffusion tensor imaging along the perivascular space (DTI-ALPS) index and choroid plexus (CP) volume in NT1 participants, and to further explore their clinical significance. MethodsWe prospectively enrolled participants diagnosed with NT1 based on cerebrospinal fluid hypocretin-1 concentration and multiple sleep latency tests at our hospital. All participants underwent MRI to allow analysis of the DTI-ALPS index and CP volume. We subsequently performed correlation analyses between the DTI-ALPS index, CP volume, and important clinical parameters, including the Epworth Sleepiness Scale (ESS) score, Narcolepsy Severity Scale (NSS) score, stage rapid eye movement sleep (REM) ratio, stage 1 non-REM (N1) ratio, stage 2 non-REM (N2) ratio, and stage 3 non-REM (N3) ratio, among the NT1 participants. Inter-group and correlation analyses of DTI-ALPS index and CP volume were performed using age, sex, body mass index, and lateral ventricle volume as covariates. ResultsThis study enrolled 41 NT1 participants and 42 healthy controls (HC). The DTI-ALPS index of NT1 participants was significantly lower than HC (1.444±0.119 vs.1.661±0.135, P<0.001), while the CP volume of NT1 participants was significantly larger than those of HC (0.831±0.146 vs. 0.645±0.137, P<0.001). The DTI-ALPS index was negatively correlated with both the ESS (PFDR-corrected<0.001) and NSS scores (PFDR-corrected=0.010), but positively correlated with the Stage N3 ratio (PFDR-corrected=0.033). The CP volume of NT1 participants was positively correlated with ESS (PFDR-corrected=0.047) and NSS scores (PFDR-corrected=0.047), but negatively correlated with the stage N3 ratio (PFDR-corrected=0.047). ConclusionOur study suggests that the DTI-ALPS index was lower and CP volume was larger in NT1 participants. The DTI-ALPS index and CP volume in the NT1 participants were related to disease severity and sleep structure. These findings may provide new insights into the mechanisms underlying NT1.

Targeting retrieval of methamphetamine reward memory in the context of REM sleep deprivation: Age-dependent role of GABAB receptors

GABAB receptors play a modulatory role in the mechanisms underlying drug addiction, sleep problems, and aging; however, there are few studies addressing their relationship. Therefore, this study aimed to examine whether blockade of these receptors affects methamphetamine (METH) reward memory in adult and adolescent rapid-eye movement sleep deprived (RSD) rats. Adolescent and adult male Wistar rats were subjected to RSD for seven days. They were then conditioned to receive methamphetamine (METH; 2 mg/kg, ip) during an eight-day conditioning period. METH reward memory was then reactivated during a retrieval trial and the GABAB receptor agonist baclofen (2.5 or 5 mg/kg, ip) was injected prior to the retrieval trial. Afterward, animals were retested for the expression of conditioned place preference (CPP) and hippocampal expression of GABAB receptors. Baclofen dose-dependently decreased the retrieval of METH reward memory in control and RSD adult and adolescent rats, but its effects were stronger at the higher dose. Moreover, we found stronger effects of baclofen in adolescent animals than in adult ones. In addition, baclofen at its higher dose decreased GABAB overexpression in the hippocampus of adolescent rats, but not in adult rats. These findings shed new light on the mechanisms underlying the role of GABAB receptors in the retrieval of METH reward memory and highlight the importance of considering age and sleep patterns in understanding addiction. Further research could potentially lead to the development of therapeutics for individuals struggling with METH addiction.

Validating the CogSleep Screener in older adults at a memory and cognition clinic.

While sleep disturbances are prevalent in older people and are linked with poor health and cognitive outcomes, screening for the range of sleep disturbances is inefficient and therefore not ideal nor routine in memory and cognition clinic settings. We aimed to develop and validate a new brief self-report questionnaire for easy use within memory and cognition clinics. The design for this study was cross-sectional. Older adults (aged ≥50 in Sydney, Australia) were recruited from a memory and cognition research clinic. Participants (N = 402, mean age 67.3 years, range 50-86, 63.6% female) completed a comprehensive medical, neuropsychological, and mental health assessment, alongside self-report instruments, including existing sleep questionnaires and a new 10-item sleep questionnaire, the CogSleep Screener. We examined the factor structure, convergent validity, internal consistency, and discriminant validity of this novel questionnaire. Using exploratory principal component analysis, a 3-factor solution was generated highlighting the factors of Insomnia, Rapid Eye Movement (REM) Symptoms and Daytime Sleepiness. Each factor was significantly correlated with currently used sleep questionnaires for each subdomain (all Spearman rho >0.3, all p < 0.001), suggesting good convergent validity. Internal consistency was also good (Cronbach's α = 0.73). Receiver operating characteristic curves showed good discriminative ability between participants with and without sleep disturbances (all area under curve >0.7, all p < 0.01). The CogSleep Screener has good psychometric properties in older to elderly adults attending a memory and cognition clinic. The instrument has the potential to be used in memory clinics and other clinical settings to provide quick and accurate screening of sleep disturbances.

Associations of polysomnographic measures of obstructive sleep apnea, and nocturnal oxygen saturation with incident type 2 diabetes mellitus in middle-aged and older men.

Obstructive sleep apnea (OSA) has been associated with incident type 2 diabetes mellitus (T2DM); however, few prospective epidemiological studies have accounted for important T2DM predictors including pre-diabetes status and testosterone. Participants in the longitudinal Men Androgens Inflammation Lifestyles Environment and Stress (MAILES) study, who underwent eight-channel home-based polysomnography (PSG) in 2010-2011 (n = 824) and were free of diabetes at baseline were included in the analysis (n = 682). From 2015 to 2021, 78.6% (n = 536) completed at least one follow-up assessment. Incident T2DM was determined by self-reported doctor diagnosis, diabetes medications, plasma glucose (fasting ≥7.0 mmol/L or random ≥11.0 mmol/L) or glycated haemoglobin ≥6.5%. Conservative hierarchical Poisson regression models adjusted associations of PSG metrics (categorical and continuous) for age, waist circumference, baseline fasting glucose and testosterone concentrations. In all, 52 men (9.7%) developed T2DM over a mean (range) of 8.3 (3.5-10.5) years. Significant age- and waist circumference-adjusted association of incident T2DM with rapid eye movement (REM) sleep apnea-hypopnea index (AHI) ≥20 events/h (incidence rate ratio [IRR] 1.5, 95% confidence interval [CI] 0.8-2.8; p = 0.23] and highest quartile of delta index (IRR 2.1, 95% CI 0.95-4.6; p = 0.066) were attenuated after adjustment for baseline glucose and testosterone, and the association with the lowest quartile of mean oxygen saturation persisted (IRR 4.2, 95% CI 1.7-10.3; p = 0.029). Categorical measures of AHI severity, oxygen desaturation index, and hypoxia burden index (HBI) were not independently associated with incident T2DM. Associations with T2DM were similar when continuous PSG variables were used; however, HBI was significant (IRR 1.015, 95% CI 1.006-1.024; p = 0.007). In a sub-sample with OSA treatment data (n = 479), these significant associations persisted after excluding adequately treated OSA (n = 32). Understanding underlying OSA endotypes generating hypoxaemia may identify opportunities for diabetes prevention.

Urodynamic study and its correlation with cardiac meta-iodobenzylguanidine (MIBG) in body-first and brain-first subtypes of Parkinson's disease.

Lower urinary tract symptoms (LUTS) are frequently observed in patients with Parkinson's disease (PD), but the underlying mechanism remains elusive. The concept of "body-first" and "brain-first" subtypes in PD has been proposed, but the correlation of PD subtype with LUTS remains unclear. We aimed to investigate the disparities in urological dysfunctions between body-first and brain-first subtypes of PD using urodynamic studies (UDS). We reviewed patients with PD (disease duration <3 years) who had undergone UDS and completed urological questionnaires (Overactive Bladder Symptom Score [OABSS] and International Prostate Symptom Score [IPSS]) and a voiding diary. Patients were categorized as having body-first or brain-first PD based on cardiac sympathetic denervation (CSD) using cardiac meta-iodobenzylguanidine (MIBG) uptake and the presence of rapid eye movement sleep behavior disorder (RBD), assessed using a questionnaire (PD with CSD and RBD indicating the body-first subtype). A total of 55 patients with PD were categorized into body-first PD (n = 37) and brain-first PD (n = 18) groups. The body-first PD group exhibited smaller voiding volume and first desire volume (FDV) than the brain-first PD group (p < 0.05 in both). Also, the body-first PD group had higher OABSS and IPSS scores, and higher prevalence of overactive bladder diagnosed by OABSS, compared to the brain-first PD group. In multiple linear regression, cardiac MIBG uptake was positively correlated with FDV and voiding volume andnegatively correlated with OABSS and IPSS (p < 0.05 in all). Patients with the body-first PD subtype exhibited more pronounced overactive bladder symptoms and impaired storage function in the early stage of disease. Additionally, cardiac MIBG was significantly associated with urological dysfunction.

Fight or flight? responses of rodents to predator cues: a review

Rodents are common prey for a wide range of predators, including reptiles, birds, and mammals. Some of the predators (e.g., owls) depend solely on rodents for food, reducing their population significantly. Rodents respond to predators by changing behaviours to protect themselves against the enemies. Further, rodents have evolved advanced sensory capabilities that enable them to detect and effectively respond to predator cues to enhance their chances of survival. If rodents can detect their predators by chemical communication, these compounds can be extracted to repel rodents away from foods in farms and houses. However, the scientific community lacks knowledge of this phenomenon. Thus, we have reviewed the literature to get enough evidence to prove that rodents respond to predators by chemical communication. Our findings demonstrated that rodents react immediately to predatory threats by hiding or sleeping, exhibiting rapid eye movements, grouping, increased alertness, aggression, heightened anxiety, reduced activity, freezing, and avoidance. Furthermore, prolonged exposure to these cues can lead to gene changes and trigger the release of stress hormones such as corticosterone. Stress in rodents can cause hormonal imbalances, leading to decreased reproduction or smaller than normal litters. This knowledge can be used to develop alternative methods for rodent control, which can reduce reliance on poisons and promote eco-friendly and sustainable approaches to managing rodent populations. However, the majority of these ant-predatory responses have only undergone laboratory testing, providing limited field-based information. Therefore, further studies are recommended to investigate ant-predatory responses, especially those involving chemical communication, in real-world environments.

Music cue during slow wave sleep improves visuospatial memory consolidation.

The active system consolidation theory assumes that sleep between encoding and retrieval promotes memory consolidation. In the present study, we cued new memories during slow-wave (SWS) or rapid eye movements (REM) sleep stages by presenting an instrumental music stimuli that had been previously presented during a learning session. In a within-subjects design, 18 participants slept for three nonconsecutive nights (cue during SWS, cue during REM, and no cue during control night) and were trained in a visuo-spatial memory task. The administration of cue during SWS produced better memory accuracy in comparison with REM and the control condition.

REM sleep and mental disorders on the 70th anniversary of the discovery of REM sleep.

The discovery of rapid eye movement sleep in 1953 led to numerous studies investigating the relationship between rapid eye movement sleep abnormalities and psychiatric disorders. The most salient findings were the association of rapid eye movement sleep alterations-reduced rapid eye movement sleep latency, increased rapid eye movement sleep volume of total sleep, and increased rapid eye movement density-with major depression. This paper briefly reviews the history of rapid eye movement sleep research in psychiatry with a focus on the work related to major depressive disorder and some of the various theories that have been proposed to explain the associated rapid eye movement sleep abnormalities. Given the increasing evidence that rapid eye movement sleep is important for emotional processing, memory and cognition, a better understanding of the underlying mechanisms for the relationship between rapid eye movement sleep and mood disorders could lead to improved treatments for these common and disabling illnesses.

Reproducible, data-driven characterization of sleep based on brain dynamics and transitions from whole-night fMRI.

Understanding the function of sleep requires studying the dynamics of brain activity across whole-night sleep and their transitions. However, current gold standard polysomnography (PSG) has limited spatial resolution to track brain activity. Additionally, previous fMRI studies were too short to capture full sleep stages and their cycling. To study whole-brain dynamics and transitions across whole-night sleep, we used an unsupervised learning approach, the Hidden Markov model (HMM), on two-night, 16 hr fMRI recordings of 12 non-sleep-deprived participants who reached all PSG-based sleep stages. This method identified 21 recurring brain states and their transition probabilities, beyond PSG-defined sleep stages. The HMM trained on one night accurately predicted the other, demonstrating unprecedented reproducibility. We also found functionally relevant subdivisions within rapid eye movement (REM) and within non-REM 2 stages. This study provides new insights into brain dynamics and transitions during sleep, aiding our understanding of sleep disorders that impact sleep transitions.

Wake-Sleep Consolidated Learning.

We propose wake-sleep consolidated learning (WSCL), a learning strategy leveraging complementary learning system (CLS) theory and the wake-sleep phases of the human brain to improve the performance of deep neural networks (DNNs) for visual classification tasks in continual learning (CL) settings. Our method learns continually via the synchronization between distinct wake and sleep phases. During the wake phase, the model is exposed to sensory input and adapts its representations, ensuring stability through a dynamic parameter freezing mechanism and storing episodic memories in a short-term temporary memory (similar to what happens in the hippocampus). During the sleep phase, the training process is split into nonrapid eye movement (NREM) and rapid eye movement (REM) stages. In the NREM stage, the model's synaptic weights are consolidated using replayed samples from the short-term and long-term memory and the synaptic plasticity mechanism is activated, strengthening important connections and weakening unimportant ones. In the REM stage, the model is exposed to previously-unseen realistic visual sensory experience, and the dreaming process is activated, which enables the model to explore the potential feature space, thus preparing synapses for future knowledge. We evaluate the effectiveness of our approach on four benchmark datasets: CIFAR-10, CIFAR-100, Tiny-ImageNet, and FG-ImageNet. In all cases, our method outperforms the baselines and prior work, yielding a significant performance gain on continual visual classification tasks. Furthermore, we demonstrate the usefulness of all processing stages and the importance of dreaming to enable positive forward transfer (FWT). The code is available at: https://github.com/perceivelab/wscl.

Temporal progression of sleep electroencephalography features in isolated rapid eye movement sleep behaviour disorder.

Previous studies indicated that patients with isolated rapid eye movement (REM) sleep behaviour disorder (iRBD) exhibit alterations in spectral electroencephalographic (EEG), spindle, and slow-wave features. As it is currently unknown how these EEG features evolve over time, this study aimed to evaluate their temporal progression in patients with iRBD in comparison to controls. We included 23 patients with iRBD and 23 controls. Two polysomnographies (baseline and follow-up) were recorded with a mean (standard deviation) interval of 4.0 (2.5) years and were automatically analysed for sleep stages, spectral bandpower, spindles, and slow waves. We used linear models to evaluate differences at each time point, and linear mixed-effects models to analyse differences in temporal progression between the groups. At baseline, patients with iRBD presented EEG slowing both in REM (expressed as significantly reduced α-bandpower and increased δ-bandpower in frontal channels) and in non-REM (NREM) sleep (significantly increased slow-to-fast ratio in central channels). These differences vanished at follow-up. In both REM and NREM sleep, γ-bandpower was increased at follow-up in patients with iRBD, resulting in significantly different temporal progression between groups (in occipital channels during REM sleep and frontal channels during NREM sleep). Relative power of sleep spindles was significantly higher at baseline in patients with iRBD in frontal channels, but we observed a significant reduction over time in central channels. Finally, slow waves were significantly shorter in patients with iRBD at both time-points. Our results underscore the need of considering longitudinal data when analysing sleep EEG features in patients with iRBD. The observed temporal changes as markers of progression of neurodegeneration require further investigations.

REM sleep remains paradoxical: sub-states determined by thalamo-cortical and cortico-cortical functional connectivity.

During paradoxical sleep (PS, aka REM sleep) the cerebral cortex displays rapid electroencephalographic activity similar to that of wakefulness, whereas in the posterior associative thalamus, rapid activity is interrupted by frequent periods of slow-wave (delta) oscillations at 2-3Hz, thereby dissociating the intrinsic frequency in thalamus and cortex. Here we studied the functional consequences of such a dissociation using intrathalamic and intracortical recordings in 21 epileptic patients, applying coherence analysis to examine changes in functional connectivity between the posterior thalamus (mainly medial pulvinar) and six cortical functional networks, and also between each cortical network with respect to the others. Periods of slow-wave thalamic activity ('delta PS') were more prevalent than phases of 'rapid PS,' and the delta/rapid thalamic alternance did not overlap with the classical tonic/phasic dichotomy based on rapid eye movements. Thalamo-cortical and cortico-cortical functional connectivity significantly decreased during delta PS, relative to both rapid PS periods and to wakefulness. The fact that delta thalamic activity and low thalamo-cortical binding coincided with a suppression of cortico-cortical connectivity supports a crucial role for the posterior associative thalamus, and particularly the medial pulvinar, in ensuring trans-thalamic communication between distant cortical areas. Disruption of such a trans-thalamic communication during delta PS compromises the functional binding between cortical areas, and consequently might contribute to the alteration of perceptual experiences commonly reported during dreams. KEY POINTS: During paradoxical, or REM, sleep (PS), rapid thalamic activity is interrupted by frequent periods of slow delta waves at 2-3Hz. During these periods of thalamic delta activity there was a drastic drop of functional connectivity between associative thalamus and cortex, and also among different cortical networks. The delta/rapid alternance did not overlap with the classically defined 'tonic/phasic' periods and therefore suggests a distinct dichotomy of functional states in PS. Recurrent decrease in thalamo-cortical and cortico-cortical functional connectivity during PS may compromise the spatio-temporal binding between cortical areas, which in turn could hinder the formation of coherent mental content during dreams.

Evaluation of continuous positive airway pressure adherence and its contributing factors

BackgroundContinuous positive airway pressure (CPAP) adherence may vary based on the study design and country. ObjectivesTo investigate long-term CPAP adherence and elucidate associated factors. MethodsA multicenter retrospective observational cohort study was conducted over two years. The study included patients diagnosed with obstructive sleep apnea who were prescribed CPAP (n = 1261). Adherence was assessed for 90 days and 365 days. Centers for Medicare and Medicaid Services (CMS) criteria (≥4 h/night on ≥70 % of nights) and research adherence criteria (≥4 h/night during the observational period) were used. Factors influencing CPAP adherence (CMS criteria) during 90 and 365 days were also evaluated. Continuous variables were categorized into low, middle, and high classes, and logistic regression analysis with interaction was performed. ResultsCPAP adherence to CMS criteria for 90 and 365 days was 45.6 % and 44.7 %, respectively, whereas adherence to research criteria was 57.0 % and 54.1 %, respectively. Middle age, high age, and high apnea ratio independently increased CPAP adherence. Conversely, a high rapid eye movement apnea-hypopnea index ratio decreased CPAP adherence. Although high body mass index (BMI) had no independent effect on adherence, its interaction with high 3 % oxygen desaturation index increased 90-day CPAP adherence. However, high BMI decreased 90-day CPAP adherence in males. The interaction between middle age and high BMI was associated with decreased CPAP adherence over 365 days. ConclusionsAdherence to CPAP in real-world settings is modest. Various factors influence CPAP adherence. BMI may exert varied effects on CPAP adherence depending on the accompanying factors.

Hypoxemia during rapid eye movement sleep mediates memory impairment in older adults at risk for dementia via CA1 hippocampal volume loss

AbstractBackground and PurposeObstructive sleep apnea is associated with increased dementia risk. Nocturnal hypoxemia, which can be more severe during rapid eye movement (REM) sleep, may be a key mechanism. This study examines how REM hypoxemia affects memory and explores whether hippocampal vulnerability to hypoxemia mediates this effect in older adults at risk for dementia.MethodsOlder adults aged ≥50 years (N = 338) with subjective or mild cognitive impairment (i.e., objective impairment) underwent neuropsychological, mood, and medical assessment, magnetic resonance imaging scanning (n = 135), and overnight polysomnography. Verbal learning and memory were assessed with the Rey Auditory Verbal Learning Test. REM sleep hypoxemia was measured using the Oxygen Desaturation Index‐3% (REM‐ODI). Hippocampal subfield (CA1, CA3, subiculum, and dentate gyrus) volumes were derived from T1 and high‐resolution hippocampus T2 scans. We determined whether the relationship between REM‐ODI and learning and memory was mediated by hippocampal subfield volume. Analyses were repeated in non‐REM sleep to determine whether the effects were REM‐specific.ResultsAlthough there was not a direct effect of REM‐ODI on verbal learning (p &gt; 0.05) or memory (p &gt; 0.05), mediation analyses showed a significant indirect effect of high REM‐ODI on poorer verbal learning (β = −0.09, 95% confidence interval [CI] = −0.238 to −0.005) and memory (β = −0.100, 95% CI = −0.255 to −0.005), which was mediated by CA1 volume. These associations were absent in non‐REM sleep (p &gt; 0.05).ConclusionsHypoxemia during REM sleep may impair memory in people at risk for dementia by reducing CA1 hippocampal volume. Research is needed to explore whether interventions targeting REM sleep hypoxemia are protective against memory decline.

Experiences and beliefs related to sleep paralysis among the general population of the twin cities: A cross-sectional study

BackgroundSleep paralysis (SP) is a rapid eye movement (REM) parasomnia that occurs during the transition between wakefulness and sleep. During this brief state, a person is conscious but unable to move or speak, often experiencing hallucinations. It is ‘isolated’ when it occurs without other symptoms of narcolepsy or sleep disorders. Despite its prevalence, much remains unknown about its clinical features and associated beliefs. ObjectivesThis study examines the frequency of self-reported SP experiences and its associated demographic characteristics, along with participants' beliefs about the condition. MethodsA cross-sectional survey was conducted among visitors at a shopping mall, using the Unusual Sleep Experiences Questionnaire (USEQ) to assess the features of SP episodes and the common beliefs surrounding them. ResultsA total of 350 participants were surveyed (mean age = 25.5 ± 9.30 years; 55.4 % females). Participants who experienced SP at least once in their life time (39.1 %) reported feeling pressure on their chest (67.2 %), an inability to open their eyes (71.5 %), and difficulty speaking (81.0 %) during the episode. The majority of the individuals reported having their first episode at a young age (16–20 years). Most people (24.5 %) were unaware that this condition was known as sleep paralysis, and many (23.5 %) thought that it was just ‘a dream’. ConclusionIsolated sleep paralysis episodes are fairly prevalent, with many people experiencing their first episode at a young age. A typical episode entails a sense of pressure on the chest and difficulty in vocalizing. Misconceptions about the condition are common and wage further exploration.

Accelerated Resolution Therapy (ART) for the treatment of posttraumatic stress disorder in adults: A systematic review

Accelerated Resolution Therapy (ART), developed in 2008, uses techniques such as rapid eye movement, in vivo exposure, and image rescripting to recondition stressful memories, and reduce physical and emotional reactions to traumatic memories. There is considerable interest in evidence-based treatments for post-traumatic stress disorder (PTSD). This is the first systematic review examining the efficacy of ART for the treatment of PTSD among adults. We searched MEDLINE, PsycINFO, Embase, CINAHL, Scopus, trial registries, and government and private websites for citations published before October 2023. Studies that reported on the effect of ART for PTSD among adults were included. Meta-analyses could not be undertaken due to heterogeneity in study designs and an insufficient number of studies with a low risk of bias. Risk of bias was assessed, and findings synthesized following the synthesis without meta-analysis (SWiM) guidelines. Of the 112 records screened, five studies (Nenrolled = 337; Ncompleted = 250) and six reports of studies met criteria for inclusion. Included studies reported a significant reduction in symptoms of PTSD from pre- to post-intervention, d = 1.12 to 3.28. Significant reductions were also reported in symptoms of depression, mental distress, anxiety, and sleep dysfunction. ART shows some promise as a time-efficient clinical treatment for symptoms of PTSD in adults; however, more high-quality studies are needed.

The Kir channel in the nucleus tractus solitarius integrates the chemosensory system with REM sleep executive machinery for homeostatic balance

The locus coeruleus (LC), nucleus tractus solitarius (NTS), and retrotrapezoid nucleus (RTN) are critical chemosensory regions in the brainstem. In the LC, acid-sensing ion channels and proton pumps serve as H+ sensors and facilitate the transition from non-rapid eye movement (NREM) to rapid eye movement (REM) sleep. Interestingly, the potassium inward rectifier (KIR) channels in the LC, NTS, and RTN also act as H+-sensors and are a primary target for improving sleep in obstructive sleep apnea and Rett syndrome patients. However, the role of Kir channels in NREM to REM sleep transition for H+ homeostasis is not known. Male Wistar rats were surgically prepared for chronic sleep–wake recording and drug delivery into the LC, NTS, and RTN. In different animal cohorts, microinjections of the Kir channel inhibitor, barium chloride (BaCl2), at concentrations of 1 mM (low dose) and 2 mM (high dose) in the LC and RTN significantly increased wakefulness and decreased NREM sleep. However, BaCl2 microinjection into the LC notably reduced REM sleep, whereas it didn’t change in the RTN-injected group. Interestingly, BaCl2 microinjections into the NTS significantly decreased wakefulness and increased the percent amount of NREM and REM sleep. Additionally, with the infusion of BaCl2 into the NTS, the mean REM sleep episode numbers significantly increased, but the length of the REM sleep episode didn’t change. These findings suggest that the Kir channels in the NTS, but not in the LC and RTN, modulate state transition from NREM to REM sleep.