Microglia mediate the increase in slow-wave sleep associated with high ambient temperature.

An increase in ambient temperature leads to an increase in sleep. However, the mechanisms behind this phenomenon remain unknown. This study aimed to investigate the role of microglia in the increase of sleep caused by high ambient temperature. We confirmed that at 35 °C, slow-wave sleep was significantly increased relative to those observed at 25 °C. Notably, this effect was abolished upon treatment with PLX3397, a CSF1R inhibitor that can deplete microglia, while sleep amount at 25 °C was unaffected. These observations suggest that microglia play a pivotal role in modulating the homeostatic regulation of sleep in response to the fluctuations in ambient temperature.

NREM Slow-Wave Activity in Adolescents Is Differentially Associated With ADHD Levels and Normalized by Pharmacological Treatment.

BACKGROUND: A compelling hypothesis about attention-deficit/hyperactivity disorder (ADHD) etiopathogenesis is that the ADHD phenotype reflects a delay in cortical maturation. Slow-wave activity (SWA) of non-rapid eye movement (NREM) sleep electroencephalogram (EEG) is an electrophysiological index of sleep intensity reflecting cortical maturation. Available data on ADHD and SWA are conflicting, and developmental differences, or the effect of pharmacological treatment, are relatively unknown. METHODS: We examined, in samples (Mage = 16.4, SD = 1.2), of ever-medicated adolescents at risk for ADHD (n = 18; 72% boys), medication-naïve adolescents at risk for ADHD (n = 15, 67% boys), and adolescents not at risk for ADHD (n = 31, 61% boys) matched for chronological age and controlling for non-ADHD pharmacotherapy, whether ADHD pharmacotherapy modulates the association between NREM SWA and ADHD risk in home sleep. RESULTS: Findings indicated medication-naïve adolescents at risk for ADHD exhibited greater first sleep cycle and entire night NREM SWA than both ever-medicated adolescents at risk for ADHD and adolescents not at risk for ADHD and no difference between ever-medicated, at-risk adolescents, and not at-risk adolescents. CONCLUSIONS: Results support atypical cortical maturation in medication-naïve adolescents at risk for ADHD that appears to be normalized by ADHD pharmacotherapy in ever-medicated adolescents at risk for ADHD. Greater NREM SWA may reflect a compensatory mechanism in middle-later adolescents at risk for ADHD that normalizes an earlier occurring developmental delay.

Effects of gabapentin on slow-wave sleep period in critically ill adult patients: A randomized controlled trial.

Sleep deprivation is a prevalent problem in critically ill patients, which leads to delayed recovery and delirium. Slow-wave sleep (SWS) is essential to energy restoration, tissue repair, and immune system strengthening. This study aimed to investigate the effects of gabapentin on SWS in critically ill patients. We performed a prospective open-label randomized controlled study to compare SWS and the clinical outcomes of gabapentin versus a control intervention in critically ill adult patients admitted to the intensive care unit (ICU) within 24 h. The patients' characteristics and sleep-related outcomes were recorded. The sleep-related outcomes, namely, bispectral analysis (BIS), the Richards-Campbell Sleep Questionnaire (RCSQ), and insulin-like growth factor-1 (IGF-1) levels, were evaluated. Furthermore, clinical outcomes and safety were assessed. Sixty patients from 348 cases were eligible for randomization. On day 3 of the study, patients in the gabapentin group had significantly increased SWS (66.79 vs. 0.00 min; p < 0.001), total sleep time (TST) (331.39 vs. 46.16 min; p = 0.001), RCSQ score (55.05 ± 20.18 vs. 32.80 ± 15.31; p < 0.001), and IGF-1 concentrations (84.33 ± 12.40 vs. 44.00 ± 10.20 ng/mL, p < 0.001) compared with the control group. Improvements in clinical outcomes, such as delirium, ICU-free days, and mechanical ventilator-free days, were observed; however, these differences did not reach statistically significant. Gabapentin at bedtime increased SWS, TST, and IGF-1 concentrations in critically ill patients. This regimen might be beneficial to critically ill patients for improving their sleep quality.

Propofol enhancement of slow wave sleep to target the nexus of geriatric depression and cognitive dysfunction: protocol for a phase I open label trial.

INTRODUCTION: Late-life treatment-resistant depression (LL-TRD) is common and increases risk for accelerated ageing and cognitive decline. Impaired sleep is common in LL-TRD and is a risk factor for cognitive decline. Slow wave sleep (SWS) has been implicated in key processes including synaptic plasticity and memory. A deficiency in SWS may be a core component of depression pathophysiology. The anaesthetic propofol can induce electroencephalographic (EEG) slow waves that resemble SWS. Propofol may enhance SWS and oral antidepressant therapy, but relationships are unclear. We hypothesise that propofol infusions will enhance SWS and improve depression in older adults with LL-TRD. This hypothesis has been supported by a recent small case series. METHODS AND ANALYSIS: SWIPED (Slow Wave Induction by Propofol to Eliminate Depression) phase I is an ongoing open-label, single-arm trial that assesses the safety and feasibility of using propofol to enhance SWS in older adults with LL-TRD. The study is enrolling 15 English-speaking adults over age 60 with LL-TRD. Participants will receive two propofol infusions 2-6 days apart. Propofol infusions are individually titrated to maximise the expression of EEG slow waves. Preinfusion and postinfusion sleep architecture are evaluated through at-home overnight EEG recordings acquired using a wireless headband equipped with dry electrodes. Sleep EEG recordings are scored manually. Key EEG measures include sleep slow wave activity, SWS duration and delta sleep ratio. Longitudinal changes in depression, suicidality and anhedonia are assessed. Assessments are performed prior to the first infusion and up to 10 weeks after the second infusion. Cognitive ability is assessed at enrolment and approximately 3 weeks after the second infusion. ETHICS AND DISSEMINATION: The study was approved by the Washington University Human Research Protection Office. Recruitment began in November 2022. Dissemination plans include presentations at scientific conferences, peer-reviewed publications and mass media. Positive results will lead to a larger phase II randomised placebo-controlled trial. TRIAL REGISTRATION NUMBER: NCT04680910.

Optochemical control of slow-wave sleep in the nucleus accumbens of male mice by a photoactivatable allosteric modulator of adenosine A2A receptors.

Optochemistry, an emerging pharmacologic approach in which light is used to selectively activate or deactivate molecules, has the potential to alleviate symptoms, cure diseases, and improve quality of life while preventing uncontrolled drug effects. The development of in-vivo applications for optochemistry to render brain cells photoresponsive without relying on genetic engineering has been progressing slowly. The nucleus accumbens (NAc) is a region for the regulation of slow-wave sleep (SWS) through the integration of motivational stimuli. Adenosine emerges as a promising candidate molecule for activating indirect pathway neurons of the NAc expressing adenosine A2A receptors (A2ARs) to induce SWS. Here, we developed a brain-permeable positive allosteric modulator of A2ARs (A2AR PAM) that can be rapidly photoactivated with visible light (λ > 400 nm) and used it optoallosterically to induce SWS in the NAc of freely behaving male mice by increasing the activity of extracellular adenosine derived from astrocytic and neuronal activity.

Electroencephalography-based investigation of the effects of oral desmopressin on improving slow-wave sleep time in nocturnal polyuria patients (the DISTINCT study): A single-arm, open-label, single-assignment trial.

AIMS: To investigate changes in subjective and objective sleep quality after desmopressin administration in patients with nocturia due to nocturnal polyuria (NP) using electroencephalography (EEG) and the Pittsburgh sleep quality index (PSQI). METHODS: Twenty male patients (≥65 years old) with NP participated in this study. The inclusion criteria were nocturnal frequency ≥ 2, NP index (NPi) ≥ 0.33, first uninterrupted sleep period (FUSP) ≤ 2.5 h, serum sodium concentration ≥ 135 mEq/L, and estimated glomerular filtration rate ≥ 50 mL/min/1.73 m2. Participants were given 50 µg of desmopressin to be taken orally once daily before bed. The primary endpoint was the change in the duration of slow-wave sleep (nonrapid eye movement sleep stages 3 and 4), as evaluated by EEG 28 days from the baseline. The visual analog scale (VAS) was used as an additional indicator of sleep quality. RESULTS: Analysis of data from 15 participants (median age: 74.0 [70.5, 76.0] years) revealed that from before to after desmopressin administration, significant decreases occurred in the median nocturnal frequency (3.0 [2.0, 4.0] to 1.5 [1.0, 2.0]) and NPi (0.445 [0.380, 0.475] to 0.360 [0.250, 0.430]). Furthermore, FUSP was significantly prolonged from 120.0 (94.0, 150.0) min to 210.0 (203.8, 311.3) min. Although the VAS scores improved, slow-wave sleep duration and the PSQI global score showed no significant differences (68.50 [47.50, 75.50] and 48.00 [38.00, 66.50]; 5.0 [5.0, 10.0] and 7.0 [5.0, 9.0] min, respectively). CONCLUSION: Oral administration of 50 µg desmopressin improved nocturnal frequency and FUSP in older individuals with NP but did not significantly enhance sleep quality. In older adults, decreased nighttime urinary frequency may enhance quality of life; however, its influence on objective sleep quality may be limited.

Noribogaine acute administration in rats promotes wakefulness and suppresses REM sleep.

Ibogaine is a potent atypical psychedelic that has gained considerable attention due to its antiaddictive and antidepressant properties in preclinical and clinical studies. Previous research from our group showed that ibogaine suppresses sleep and produces an altered wakefulness state, which resembles natural REM sleep. However, after systemic administration, ibogaine is rapidly metabolized to noribogaine, which also shows antiaddictive effects but with a distinct pharmacological profile, making this drug a promising therapeutic candidate. Therefore, we still ignore whether the sleep/wake alterations depend on ibogaine or its principal metabolite noribogaine. To answer this question, we conducted polysomnographic recordings in rats following the administration of pure noribogaine. Our results show that noribogaine promotes wakefulness while reducing slow-wave sleep and blocking REM sleep, similar to our previous results reported for ibogaine administration. Thus, we shed new evidence on the mechanisms by which iboga alkaloids work in the brain.

Chemogenetic modulation of histaminergic neurons in the tuberomamillary nucleus alters territorial aggression and wakefulness.

Designer receptor activated by designer drugs (DREADDs) techniques are widely used to modulate the activities of specific neuronal populations during behavioural tasks. However, DREADDs-induced modulation of histaminergic neurons in the tuberomamillary nucleus (HATMN neurons) has produced inconsistent effects on the sleep-wake cycle, possibly due to the use of Hdc-Cre mice driving Cre recombinase and DREADDs activity outside the targeted region. Moreover, previous DREADDs studies have not examined locomotor activity and aggressive behaviours, which are also regulated by brain histamine levels. In the present study, we investigated the effects of HATMN activation and inhibition on the locomotor activity, aggressive behaviours and sleep-wake cycle of Hdc-Cre mice with minimal non-target expression of Cre-recombinase. Chemoactivation of HATMN moderately enhanced locomotor activity in a novel open field. Activation of HATMN neurons significantly enhanced aggressive behaviour in the resident-intruder test. Wakefulness was increased and non-rapid eye movement (NREM) sleep decreased for an hour by HATMN chemoactivation. Conversely HATMN chemoinhibition decreased wakefulness and increased NREM sleep for 6 h. These changes in wakefulness induced by HATMN modulation were related to the maintenance of vigilance state. These results indicate the influences of HATMN neurons on exploratory activity, territorial aggression, and wake maintenance.

Effects of propofol on sleep architecture and sleep-wake systems in rats.

Previous studies have shown that the synchronization of electroencephalogram (EEG) signals is found during propofol-induced general anesthesia, which is similar to that of slow-wave sleep (SWS). However, a complete understanding is lacking in terms of the characteristics of EEG changes in rats after propofol administration and whether propofol acts through natural sleep circuits. Here, we examined the characteristics of EEG patterns induced by intraperitoneal injection of propofol in rats. We found that high (10 mg/kg) and medium (5 mg/kg) doses of propofol induced a cortical EEG of low-frequency, high-amplitude activity with rare electromyographic activity and markedly shortened sleep latency. The high dose of propofol increased deep slow-wave sleep (SWS2) to 4 h, as well as the number of large SWS2 bouts (>480 s), their mean duration and the peak of the power density curve in the delta range of 0.75-3.25 Hz. After the medium dose of propofol, the total number of wakefulness, light slow-wave sleep (SWS1) and SWS2 episodes increased, whereas the mean duration of wakefulness decreased. The high dose of propofol significantly increased c-fos expression in the ventrolateral preoptic nucleus (VLPO) sleep center and decreased the number of c-fos-immunoreactive neurons in wake-related systems including the tuberomammillary nucleus (TMN), perifornical nucleus (PeF), lateral hypothalamic nucleus (LH), ventrolateral periaqueductal gray (vPAG) and supramammillary region (SuM). These results indicated that the high dose of propofol produced high-quality sleep by increasing SWS2, whereas the medium dose produced fragmented and low-quality sleep by disrupting the continuity of wakefulness. Furthermore, sleep-promoting effects of propofol are correlated with activation of the VLPO cluster and inhibition of the TMN, PeF, LH, vPAG and SuM.

Sleep and alertness disturbance and substance use disorders: A bi-directional relation.

The majority of the literature describing the relation of sleep/alertness disturbance and substance use disorders (SUD) has focused on the disruptive effects of substances with abuse liability on sleep and alertness. Rarely have studies or literature reviews assessed or discussed how sleep/alertness disturbance affects substance use. This paper focuses on the sleep/alertness disturbance side of the relation. We argue that the relation is bi-directional and review evidence showing that sleep/alertness disturbance affects all phases of the addiction cycle, including the initiation, maintenance and relapse of SUD. We review a variety of substances across all phases of the addiction cycle and conclude sleep/alertness disturbance is a critical factor in both understanding and treating SUD.

Treatment Practices and Outcomes in Continuous Spike and Wave during Slow Wave Sleep: A Multicenter Collaboration.

OBJECTIVES: To determine how continuous spike and wave during slow wave sleep (CSWS) is currently managed and to compare the effectiveness of current treatment strategies using a database from 11 pediatric epilepsy centers in the US. STUDY DESIGN: This retrospective study gathered information on baseline clinical characteristics, CSWS etiology, and treatment(s) in consecutive patients seen between 2014 and 2016 at 11 epilepsy referral centers. Treatments were categorized as benzodiazepines, steroids, other antiseizure medications (ASMs), or other therapies. Two measures of treatment response (clinical improvement as noted by the treating physician; and electroencephalography improvement) were compared across therapies, controlling for baseline variables. RESULTS: Eighty-one children underwent 153 treatment trials during the study period (68 trials of benzodiazepines, 25 of steroids, 45 of ASMs, 14 of other therapies). Children most frequently received benzodiazepines (62%) or ASMs (27%) as first line therapy. Treatment choice did not differ based on baseline clinical variables, nor did these variables correlate with outcome. After adjusting for baseline variables, children had a greater odds of clinical improvement with benzodiazepines (OR 3.32, 95%CI 1.57-7.04, P = .002) or steroids (OR 4.04, 95%CI 1.41-11.59, P = .01) than with ASMs and a greater odds of electroencephalography improvement after steroids (OR 3.36, 95% CI 1.09-10.33, P = .03) than after ASMs. CONCLUSIONS: Benzodiazepines and ASMs are the most frequent initial therapy prescribed for CSWS in the US. Our data suggests that ASMs are inferior to benzodiazepines and steroids and support earlier use of these therapies. Multicenter prospective studies that rigorously assess treatment protocols and outcomes are needed.

A pilot study on essential oil aroma stimulation for enhancing slow-wave EEG in sleeping brain.

Sleep quality is important to health and life quality. Lack of sleep can lead to a variety of health issues and reduce in daytime function. Recent study by Fultz et al. also indicated that sleep is crucial to brain metabolism. Delta power in sleep EEG often indicates good sleep quality while alpha power usually indicates sleep interruptions and poor sleep quality. Essential oil has been speculated to improve sleep quality. Previous studies also suggest essential oil aroma may affect human brain activity when applied awake. However, those studies were often not blinded, which makes the effectiveness and mechanism of aroma a heavily debated topic. In this study, we aim to explore the effect of essential oil aroma on human sleep quality and sleep EEG in a single-blinded setup. The aroma was released when the participants are asleep, which kept the influence of psychological expectation to the minimum. We recruited nine young, healthy participants with regular lifestyle and no sleep problem. All participants reported better sleep quality and more daytime vigorous after exposing to lavender aroma in sleep. We also observed that upon lavender aroma releases, alpha wave in wake stage was reduced while delta wave in slow-wave sleep (SWS) was increased. Lastly, we found that lavender oil promote occurrence of SWS. Overall, our study results show that essential oil aroma can be used to promote both subjective and objective sleep quality in healthy human subjects. This makes aroma intervention a potential solution for poor sleep quality and insomnia.

A randomized phase 1 single-dose polysomnography study of ASP8062, a GABAB receptor positive allosteric modulator.

RATIONALE: Previous research suggests that sleep polysomnography and EEG endpoints can be used to assess GABAergic activity; however, the impact of GABAB receptor positive allosteric modulators on sleep endpoints remains unclear. OBJECTIVES: This phase 1 study compared a single dose of ASP8062 (35 mg or 70 mg), a GABAB receptor positive allosteric modulator, with placebo and paroxetine (40 mg). METHODS: Healthy adult volunteers were randomized to four treatments (35 mg ASP8062, 70 mg ASP8062, paroxetine 40 mg, or matching placebo), each separated by a 14-day washout. Primary endpoints obtained by polysomnography were time in stage N3 or SWS and time in rapid eye movement (REM) sleep. Secondary endpoints included impact on sleep stages and electroencephalography parameters, pharmacokinetics, nighttime growth hormone (GH), and safety/tolerability. RESULTS: In 20 randomized volunteers, ASP8062 led to a significant and seemingly dose-dependent increase in SWS over the entire night; this increase was mainly observed during the first third of the night. ASP8062 did not impact time in REM sleep. Paroxetine had no effect on SWS but produced a significant reduction in time spent in REM sleep. A dose-dependent trend in increased GH release was also observed with ASP8062. Headache and nausea were the most commonly reported treatment-emergent adverse events (TEAEs) for ASP8062; most TEAEs were mild in severity. CONCLUSIONS: Single-dose ASP8062 (35 and 70 mg) appeared to result in CNS penetration and enhanced GABAergic activity as measured by increases in slow-wave sleep and growth hormone release.

Disparate effects of hormones and vigabatrin on sleep slow waves in patients with West syndrome - An indication of their mode of action?

Synaptic downscaling during sleep, a physiological process to restore synaptic homeostasis and maintain learning efficiency and healthy brain development, has been related to a reduction of the slope of sleep slow waves (SSW). However, such synaptic downscaling seems not to be reflected in high-amplitude SSW. Recently we have shown reduced SSW slopes during hormonal treatment (adrenocorticotrophic hormone, prednisolone) in patients with West syndrome (WS). Yet, whether this reduction was related to successful treatment or reflects a specific effect of hormone therapy is unknown. Thus, we retrospectively analysed nap electroencephalograms of 61 patients with WS successfully treated with hormones, vigabatrin (VGB), or both. The slope of SSW during treatment (T1) and 2-7 months later (T2) when hormonal treatment was tapered off were compared between the treatment groups and healthy, age-matched controls. At T1 hormone treatment reduced the slope of low-amplitude SSW, whereas VGB increased the slope of high-amplitude SSW (linear mixed effect model: FGroup  = 7.04, p < 0.001; FAmplitude  = 1,646.68, p < 0.001; FGroup*Amplitude  = 3.38, p < 0.001). At T2, untreated patients did not differ anymore from healthy controls, whereas those still under VGB showed the same alterations as those with VGB at T1. This result indicates a disparate effect of VGB and hormone on the SSW slope. In particular, hormones seem to reduce the slope of cortical generated low-amplitude SSW, similar to the physiological synaptic downscaling during sleep. Thus, a loss of functional neuronal connectivity might be an alternative explanation of the antiepileptic effect of hormonal treatment.

Pharmacological treatment for continuous spike-wave during slow wave sleep syndrome and Landau-Kleffner Syndrome.

BACKGROUND: Continuous spike-wave during slow wave sleep syndrome (CSWS) and Landau-Kleffner syndrome (LKS) are two epileptic encephalopathies that present with neurocognitive regression, aphasia, and clinical seizures, typically presenting in children around five years of age. The pathophysiology of these conditions is not completely understood. Some studies suggest a common origin for both. No systematic reviews have assessed the efficacy of pharmacological interventions for these conditions. OBJECTIVES: To assess the benefit and adverse effects of pharmacological interventions for the treatment of CSWS and LKS. SEARCH METHODS: On 8 September 2020, we searched the Cochrane Register of Studies (CRS Web) and MEDLINE Ovid (1946 to September 04, 2020). We applied no language restrictions. CRS Web includes randomised or quasi-randomised, controlled trials from CENTRAL, PubMed, Embase, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform. SELECTION CRITERIA: Randomised controlled trials, quasi-randomised controlled trials, and cluster-randomised trials comparing antiepileptic drugs alone, or with steroids or intravenous immunoglobulins, or both versus other antiepileptic drugs, or placebo, or no treatment, administered to children with CSWS and LKS. We planned to compare treatments for the two conditions separately. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed studies identified by the search strategy for inclusion. The primary outcomes considered in this review were neuropsychological-neurolinguistic functions. MAIN RESULTS: Our search strategy yielded 18 references. Two review authors independently assessed all references. We did not find any completed studies to include. We identified one ongoing trial, which was terminated because of lack of enrolment. AUTHORS' CONCLUSIONS: There was no evidence from trials to support or refute the use of pharmacological treatment for continuous spike-wave during slow wave sleep syndrome or Landau-Kleffner syndrome. Well-designed randomised controlled trials are needed to inform practice.

Rationale, design, and methods of electroencephalography-based investigation of the effects of oral desmopressin on improving slow-wave sleep time in nocturnal polyuria patients (the DISTINCT study): protocol for a single-arm, open-label, single-assignment trial.

BACKGROUND: Nocturia is one of the most bothersome lower urinary tract symptoms and often impairs sleep quality in the elderly. Although previous studies on nocturia have indicated that the successful treatment of nocturia improves sleep quality, most used questionnaires and activity devices to analyze sleep/wake patterns. Therefore, there is little information about the treatment effects of desmopressin on objective sleep quality. The aim of the DISTINCT study is to investigate the change in subjective and objective sleep quality using electroencephalography (EEG) and the Pittsburgh Sleep Quality Index (PSQI) after the administration of desmopressin in patients with nocturia due to nocturnal polyuria. METHODS: A total of 20 male patients, ≥65 years old, with nocturnal polyuria, defined as a nocturnal polyuria index (NPi) (nocturnal urine volume / 24 h urine volume) value ≥0.33, will participate in this study. The participants must have a nocturnal frequency of ≥2 and the first uninterrupted sleep period (FUSP) must occur within < 2.5 h. Desmopressin 50 µg per day will be orally administered before going to bed for 4 weeks. Urinary frequency volume charts (FVC) and EEG will be recorded prior to treatment and at 1 week and 4 weeks after the initiation of treatment. The PSQI will be completed before and 4 weeks after treatment. The primary endpoint is the change from baseline in the mean time of slow-wave sleep (sleep stages N3 and N4) at 4 weeks. The secondary endpoints include the change in the mean value of each sleep variable, the mean delta power during the FUSP, the correlation between nocturnal urinary frequency and slow-wave sleep time, and the change in PSQI score before and after treatment. DISCUSSION: The DISTINCT study will provide valuable evidence to indicate that oral desmopressin treatment for nocturnal polyuria prolongs the FUSP, resulting in the extension of slow-wave sleep time associated with sleep quality. TRIAL REGISTRATION: The Japan Registry of Clinical Trials ( jRCTs051190080 ). Registered 9 December, 2019.

Effects of an Orexin-2 Receptor Antagonist on Sleep and Event-Related Oscillations in Female Rats Exposed to Chronic Intermittent Ethanol During Adolescence.

BACKGROUND: Alcohol use is on the rise among women in the United States which is especially concerning since women who drink have a higher risk of alcohol-related problems. Orexin (hypocretin) receptor antagonists may have some therapeutic value for alcohol-induced insomnia; however, the use of this class of drugs following female adolescent binge drinking is limited. The current study will address whether adolescent intermittent ethanol (AIE) in female rats can result in lasting changes in sleep pathology and whether orexin-targeted treatment can alleviate these deficits. METHODS: Following a 5-week AIE vapor model, young adult rats were evaluated on waking event-related oscillations (EROs) and EEG sleep. Subsequently, AIE rats were treated with orexin receptor 2 (OX2 R) antagonist (MK-1064; 10, 20mg/kg) to test for modifications in sleep pathology and waking ERO. RESULTS: Female AIE rats exhibited lasting changes in sleep compared to controls. This was demonstrated by increased fragmentation of slow wave sleep (SWS) and rapid eye movement sleep, as well as reductions in delta and theta power during SWS. There was no impact of AIE on waking EROs. Acute MK-1064 hastened SWS onset and increased the number of SWS episodes, without increasing sleep fragmentation in AIE and controls. While treatment with MK-1064 did not impact sleep EEG spectra, waking ERO energy was increased in delta, theta, and beta frequency bands. CONCLUSIONS: These results demonstrate that AIE can produce lasting changes in sleep in female rats, highly similar to what we previously found in males. Additionally, while the OX2 R antagonist promoted sleep in both alcohol-exposed and unexposed rats, it did not reverse most of the alcohol-induced disruptions in sleep. Thus, OX2 R antagonism may serve as a potential therapeutic strategy for the treatment of insomnia, but not the specific signs of alcohol-induced insomnia.

Cholinergic Switch between Two Types of Slow Waves in Cerebral Cortex.

Sleep slow waves are known to participate in memory consolidation, yet slow waves occurring under anesthesia present no positive effects on memory. Here, we shed light onto this paradox, based on a combination of extracellular recordings in vivo, in vitro, and computational models. We find two types of slow waves, based on analyzing the temporal patterns of successive slow-wave events. The first type is consistently observed in natural slow-wave sleep, while the second is shown to be ubiquitous under anesthesia. Network models of spiking neurons predict that the two slow wave types emerge due to a different gain on inhibitory versus excitatory cells and that different levels of spike-frequency adaptation in excitatory cells can account for dynamical distinctions between the two types. This prediction was tested in vitro by varying adaptation strength using an agonist of acetylcholine receptors, which demonstrated a neuromodulatory switch between the two types of slow waves. Finally, we show that the first type of slow-wave dynamics is more sensitive to external stimuli, which can explain how slow waves in sleep and anesthesia differentially affect memory consolidation, as well as provide a link between slow-wave dynamics and memory diseases.

Sleep EEG slow-wave activity in medicated and unmedicated children and adolescents with attention-deficit/hyperactivity disorder.

Slow waves (1-4.5 Hz) are the most characteristic oscillations of deep non-rapid eye movement sleep. The EEG power in this frequency range (slow-wave activity, SWA) parallels changes in cortical connectivity (i.e., synaptic density) during development. In patients with attention-deficit/hyperactivity disorder (ADHD), prefrontal cortical development was shown to be delayed and global gray matter volumes to be smaller compared to healthy controls. Using data of all-night recordings assessed with high-density sleep EEG of 50 children and adolescents with ADHD (mean age: 12.2 years, range: 8-16 years, 13 female) and 86 age- and sex-matched healthy controls (mean age: 12.2 years, range: 8-16 years, 23 female), we investigated if ADHD patients differ in the level of SWA. Furthermore, we examined the effect of stimulant medication. ADHD patients showed a reduction in SWA across the whole brain (-20.5%) compared to healthy controls. A subgroup analysis revealed that this decrease was not significant in patients who were taking stimulant medication on a regular basis at the time of their participation in the study. Assuming that SWA directly reflects synaptic density, the present findings are in line with previous data of neuroimaging studies showing smaller gray matter volumes in ADHD patients and its normalization with stimulant medication.

Neural signatures of sleep in zebrafish.

Slow-wave sleep and rapid eye movement (or paradoxical) sleep have been found in mammals, birds and lizards, but it is unclear whether these neuronal signatures are found in non-amniotic vertebrates. Here we develop non-invasive fluorescence-based polysomnography for zebrafish, and show-using unbiased, brain-wide activity recording coupled with assessment of eye movement, muscle dynamics and heart rate-that there are at least two major sleep signatures in zebrafish. These signatures, which we term slow bursting sleep and propagating wave sleep, share commonalities with those of slow-wave sleep and paradoxical or rapid eye movement sleep, respectively. Further, we find that melanin-concentrating hormone signalling (which is involved in mammalian sleep) also regulates propagating wave sleep signatures and the overall amount of sleep in zebrafish, probably via activation of ependymal cells. These observations suggest that common neural signatures of sleep may have emerged in the vertebrate brain over 450 million years ago.