GABA mechanisms and sleep

Quercetin-3-O-glucuronide in the Ethanol Extract of Lotus Leaf (Nelumbo nucifera) Enhances Sleep Quantity and Quality in a Rodent Model via a GABAergic Mechanism

Current pharmacological treatments for insomnia carry several and long-term side effects. Therefore, natural products without side effects are warranted. In this study, the sleep-promoting activity of the lotus leaf (Nelumbo nucifera) extract was assessed using ICR mice and Sprague Dawley rats. A pentobarbital-induced sleep test and electroencephalogram analysis were conducted to measure sleep latency time, duration, and sleep architecture. The action mechanism of the extract was evaluated through ligand binding experiments. A high dose (300 mg/kg) of the ethanolic lotus leaf extract significantly increased sleep duration compared to the normal group (p < 0.01). Administration of low (150 mg/kg) and high doses (300 mg/kg) of the extract significantly increased sleep quality, especially the relative power of theta waves (p < 0.05), compared to the normal group. Furthermore, caffeine and lotus leaf extract administration significantly recovered caffeine-induced sleep disruption (p < 0.001), and the sleep quality was similar to that of the normal group. Additionally, ligand binding assay using [3H]-flumazenil revealed that quercetin-3-O-glucuronide contained in the lotus leaf extract (77.27 μg/mg of extract) enhanced sleep by binding to GABAA receptors. Collectively, these results indicated that the lotus leaf extract, particularly quercetin-3-O-glucuronide, exhibits sleep quantity- and quality-enhancing activity via the GABAergic pathway.

Artificial light at night interacts with predatory threat to alter reef fish metabolite profiles

Light cycles and predatory threat define activity patterns (e.g. feeding/sleeping, activity/rest) in most diurnal fish species. Artificial light at night (ALAN) may disrupt natural cycles and biochemical processes, a mismatch which can eventually reduce condition and fitness. We evaluate the separate and joint effects of ALAN and predator threat on metabolism within brain, liver and muscle tissue of a common, wild caught damselfish, blue green chromis (Chromis viridis). The effects of ALAN varied according to tissue type and predator exposure. In all tissues we observed changes in metabolic pathways associated with increased activity under continuous light (despite provision of shelter), specifically those associated with energy metabolism, cell signalling, responses to oxidative stress and markers of cellular damage. In both the brain and liver tissues, predator threat served to moderate the influence of ALAN on metabolic change, likely due to increased sheltering behaviour. However, no interaction of predator threat with ALAN was observed in metabolism of the muscle tissue. Our results highlight complex sub-acute effects of ALAN exposure on tissue specific and whole organism energy metabolism. Collectively these effects indicate that ALAN has significant scope to reduce fitness of coastal fishes and potentially threaten ecosystem services, but that these changes are highly complex and may be altered by biotic drivers of activity.

Hypnotic Effect of A. absinthium Hydroalcoholic Extract in Pentobarbital-Treated Mice

BACKGROUND

Current drugs used in the management of insomnia are associated with side effects. The use of medicinal herbs for insomnia treatment has recently been suggested.

OBJECTIVE

The present study aimed to determine the hypnotic activity of the hydroalcoholic extract of Artemisia absinthium (A. absinthium) in mice.

METHOD

The toxicity of A. absinthium extract is assessed by their lethal dose 50% (LD50), and cytotoxicity evaluation was also done with PC12 cell lines by MTT assay. A. absinthium extract (25, 50, 100, and 200 mg/kg) and 3 fractions (n-butanol fraction (NBF), ethyl acetate fraction (EAF), and aqueous fraction (AQF)) were administered intraperitoneally30 minutes before 30 mg/kg pentobarbital intraperitoneal injection; after that, the sleeping time and sleep latency were recorded.

RESULTS

The LD50 value was 2.4 g/kg. The extracts tested showed no negative effect on the proliferation of PC12 cells. A. absinthium extract increased the duration of pentobarbital-induced sleep at doses of 100 and 200 mg/kg (P < 0.01-P < 0.001). Similarly, AQF, EAF, and NBF at 200 mg/kg could increase sleep duration (P < 0.05). The sleep latency was decreased by A. absinthium extract at doses of 100 and 200 mg/kg (P < 0.05-P < 0.01), AQF (P < 0.05), and EAF (P < 0.05). Besides, flumazenil reversed the hypnotic effect of A. absinthium extract (P < 0.05).

CONCLUSION

A. absinthium extract probably demonstrated sleep-enhancing effects by regulating GABAergic system.

Modeling sleep onset misperception in insomnia

OBJECTIVES

To extend and validate a previously suggested model of the influence of uninterrupted sleep bouts on sleep onset misperception in a large independent data set.

METHODS

Polysomnograms and sleep diaries of 139 insomnia patients and 92 controls were included. We modeled subjective sleep onset as the start of the first uninterrupted sleep fragment longer than Ls minutes, where parameter Ls reflects the minimum length of a sleep fragment required to be perceived as sleep. We compared the so-defined sleep onset latency (SOL) for various values of Ls. Model parameters were compared between groups, and across insomnia subgroups with respect to sleep onset misperception, medication use, age, and sex. Next, we extended the model to incorporate the length of wake fragments. Model performance was assessed by calculating root mean square errors (RMSEs) of the difference between estimated and perceived SOL.

RESULTS

Participants with insomnia needed a median of 34 minutes of undisturbed sleep to perceive sleep onset, while healthy controls needed 22 minutes (Mann-Whitney U = 4426, p < 0.001). Similar statistically significant differences were found between sleep onset misperceivers and non-misperceivers (median 40 vs. 20 minutes, Mann-Whitney U = 984.5, p < 0.001). Model outcomes were similar across other subgroups. Extended models including wake bout lengths resulted in only marginal improvements of model outcome.

CONCLUSIONS

Patients with insomnia, particularly sleep misperceivers, need larger continuous sleep bouts to perceive sleep onset. The modeling approach yields a parameter for which we coin the term Sleep Fragment Perception Index, providing a useful measure to further characterize sleep state misperception.

Bi-Temporal Anodal Transcranial Direct Current Stimulation during Slow-Wave Sleep Boosts Slow-Wave Density but Not Memory Consolidation

Slow-wave sleep (SWS) has been shown to promote long-term consolidation of episodic memories in hippocampo–neocortical networks. Previous research has aimed to modulate cortical sleep slow-waves and spindles to facilitate episodic memory consolidation. Here, we instead aimed to modulate hippocampal activity during slow-wave sleep using transcranial direct current stimulation in 18 healthy humans. A pair-associate episodic memory task was used to evaluate sleep-dependent memory consolidation with face–occupation stimuli. Pre- and post-nap retrieval was assessed as a measure of memory performance. Anodal stimulation with 2 mA was applied bilaterally over the lateral temporal cortex, motivated by its particularly extensive connections to the hippocampus. The participants slept in a magnetic resonance (MR)-simulator during the recordings to test the feasibility for a future MR-study. We used a sham-controlled, double-blind, counterbalanced randomized, within-subject crossover design. We show that stimulation vs. sham significantly increased slow-wave density and the temporal coupling of fast spindles and slow-waves. While retention of episodic memories across sleep was not affected across the entire sample of participants, it was impaired in participants with below-average pre-sleep memory performance. Hence, bi-temporal anodal direct current stimulation applied during sleep enhanced sleep parameters that are typically involved in memory consolidation, but it failed to improve memory consolidation and even tended to impair consolidation in poor learners. These findings suggest that artificially enhancing memory-related sleep parameters to improve memory consolidation can actually backfire in those participants who are in most need of memory improvement.

Transcranial magnetic stimulation therapeutic applications on sleep and insomnia: a review

Repetitive transcranial magnetic stimulation (rTMS) is a neuromodulatory technique approved by the US Food and Drug Administration for use in treatment-resistant major depressive disorder. It works by generating localized magnetic fields that create depolarizing electrical currents in neurons a few centimeters below the scalp. This localized effect is believed to stimulate neural plasticity, activate compensatory processes, and influence cortical excitability. Additionally, rTMS has been used in a variety of clinical trials for neurological and psychiatric conditions such as anxiety, post-traumatic stress disorder and epilepsy. Beneficial effects in sleep parameters have been documented in these trials, as well as in major depressive disorder, and have led to an interest in using rTMS in the field of sleep medicine for specific disorders such as insomnia, hypersomnia, and restless legs syndrome. It is unknown whether rTMS has intrinsically beneficial properties when applied to primary sleep disorders, or if it only acts on sleep through mood disorders. This narrative review sought to examine available literature regarding the application of rTMS for sleep disorder to identify knowledge gaps and inform future study design. The literature in this area remains scarce, with few randomized clinical trials on rTMS and insomnia. Available studies have found mixed results, with some studies reporting subjective sleep improvement while objective improvement is less consistent. Due to the heterogeneity of results and the variations in rTMS protocols, no definitive conclusions have been reached, signaling the need for further research.

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 GABA_B 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 GABA_B 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.

Synthetic and Natural Derivatives of Cannabidiol

The non-psychoactive component of Cannabis Sativa, cannabidiol (CBD), has centered the attention of a large body of research in the last years. Recent clinical trials have led to the FDA approval of CBD for the treatment of children with drug-resistant epilepsy. Even though it is not yet in clinical phases, its use in sleep-wake pathological alterations has been widely demonstrated.Despite the outstanding current knowledge on CBD therapeutic effects in numerous in vitro and in vivo disease models, diverse questions still arise from its molecular pharmacology. CBD has been shown to modulate a wide variety of targets including the cannabinoid receptors, orphan GPCRs such as GPR55 and GPR18, serotonin, adenosine, and opioid receptors as well as ligand-gated ion channels among others. Its pharmacology is rather puzzling and needs to be further explored in the disease context.Also, the metabolism and interactions of this phytocannabinoid with other commercialized drugs need to be further considered to elucidate its clinical potential for the treatment of specific pathologies.Besides CBD, natural and synthetic derivatives of this chemotype have also been reported exhibiting diverse functional profiles and providing a deeper understanding of the potential of this scaffold.In this chapter, we analyze the knowledge gained so far on CBD and its analogs specially focusing on its molecular targets and metabolic implications. Phytogenic and synthetic CBD derivatives may provide novel approaches to improve the therapeutic prospects offered by this promising chemotype.

Lilium davidii extract alleviates p‑chlorophenylalanine‑induced insomnia in rats through modification of the hypothalamic-related neurotransmitters, melatonin and homeostasis of the hypothalamic-pituitary-adrenal axis

CONTEXT

Lilium davidii var. unicolour Cotton (Lilium genus, Liliaceae) is an edible plant and a herb used in China to alleviate insomnia.

OBJECTIVE

To investigate the alleviating insomnia mechanism of L. davidii (LD).

MATERIALS AND METHODS

Wistar rats were intraperitoneally injected with p-chlorophenylalanine (PCPA) to establish an insomnia model. Rats were divided into six groups (n = 8): Control, PCPA, Estazolam (0.5 mg/kg), LD extract in low, medium and high doses (185.22, 370.44, 740.88 mg/kg). Serum hormone levels of the HPA axis, levels of 5-HT, NE and MT, and the expression of GABA_A and 5-HT1A receptors in hypothalamus were determined. Moreover, behavioural and pathological changes in the hypothalamus were evaluated.

RESULTS

After LD administration, body weight and brain coefficient increased by 2.74% and 8.22%, respectively, and the adrenal coefficient decreased by 25%, compared with PCPA group. Elevation of the serum hypothalamic-pituitary-adrenal (HPA) axis hormone CRH (11.24 ± 3.16 ng/mL), ACTH (565.87 ± 103.44 pg/mL) and CORT (44.28 ± 8.73 ng/mL) in the PCPA group was reversed after LD treatment. Furthermore, abnormal excitatory behaviour [5 min movement distance (2096.34 ± 259.51 cm), central exercise time (5.28 ± 1.08 s)] of insomnia rats in the PCPA group was also relieved. LD extract increased 5-HT and MT levels, reduced NE level in the hypothalamus, and upregulated the expression of GABA_A R and 5-HT1A. Moreover, LD extract may improve the pathology of neurons in the hypothalamus.

CONCLUSIONS

LD can be considered to develop health-care food or novel drugs to cope with the increasing number of insomniacs.

Gut-Brain-Skin Axis in Psoriasis: A Review

Introduction

Psoriasis is a common skin disease, with chronic inflammation and a complex etiology. It has long been recognized that chronic skin conditions and mental health disorders are often co-morbid. Thus, the concept of the gut–brain–skin axis emphasized in mental health disorders may also regulate the health of skin.

Results

The gut microbiota has been found to be the bridge between the immune system and nervous system. By leveraging clinical cases and animal models of psoriasis, an important communication pathway has been identified along the gut–brain–skin axis that is associated with the modulation of neurotransmitters from the microbiota. Furthermore, mammalian neurotransmitters, including dopamine, serotonin, or γ-aminobutyric acid (GABA), can be produced and/or consumed by several types of bacteria. Other studies suggest that manipulating these neurotransmitters by bacteria may have an effect on host physiology, and the levels of neurotransmitter can be altered by microbiota-based interventions.

Conclusions

Nonetheless, it is unknown whether or not the manipulation of neurotransmitter levels by bacteria can affect the occurrence and development of psoriasis. Notably, preliminary experiments found that oral consumption of probiotics improves the clinical symptoms in patients with psoriasis, perhaps correlated with the gut microbiome-mediated crosstalk between the immune system and the nervous system by secreting neurotransmitters in psoriasis. In this review, the communication along the gut–brain–skin axis is discussed.

Combination of MS Binding Assays and affinity selection mass spectrometry for screening of structurally homogenous libraries as exemplified for a focused oxime library addressing the neuronal GABA transporter 1

This study presents an efficient screening approach based on combination of mass spectrometry (MS) based binding assays (MS Binding Assays) and affinity selection mass spectrometry (ASMS) customized for screening of structurally homogeneous libraries sharing a common mass spectrometric fragmentation pattern. After reaction of a nipecotic acid derivative possessing a hydroxylamine functionality with aldehydes, the resulting oxime library was screened accordingly toward the GABA transporter subtype 1 (GAT1), a drug target for several neurological disorders. After assessing sublibraries' activities for inhibition of reporter ligand binding, hits in active ones were directly identified. This could be achieved by recording mass transitions for the reporter ligand as well as those predicted for the library components in a single LC-MS/MS run with a triple quadrupole mass spectrometer in the multiple reaction monitoring mode. Identification of hits with a predefined affinity could be reliably accomplished by calculation of IC₅₀-values from specific binding concentrations of library constituents and reporter ligand. Application of this strategy revealed six hits, from which two of them were resynthesized for further biological evaluation. Thereby, the best one displayed a pK_i of 7.38 in MS Binding Assays and a pIC₅₀ of 6.82 in [³H]GABA uptake assays for GAT1.

Frontal electroencephalogram activity during emergence from general anaesthesia in children with and without emergence delirium

BACKGROUND

Emergence delirium (ED) in children after general anaesthesia causes significant distress in patients, their family members, and clinicians; however, electroencephalogram (EEG) markers predicting ED have not been fully investigated.

METHODS

This prospective, single-centre observational study enrolled children aged 2-10 yr old under sevoflurane anaesthesia. ED was assessed according to Diagnostic and Statistical Manual of Mental Disorders (DSM) IV or 5 criteria. The relative power of low-frequency (delta and theta) and high-frequency (alpha and beta) EEG waves during the emergence period was compared between the children with and without ED. The linear relationships between the relative power and peak Paediatric Assessment of Emergence Delirium (PAED) score were investigated.

RESULTS

Among the 60 patients, 22 developed ED (ED group), whereas the other 38 did not (non-ED group). The relative power of the delta wave was higher (mean [standard deviation], 0.579 [0.083] vs 0.453 [0.090], respectively, P<0.001) in the ED group, whereas that of the alpha and beta waves was lower in the ED group, than in the non-ED group (0.155 [0.063] vs 0.218 [0.088], P=0.005 and 0.114 [0.069] vs 0.186 [0.070], P<0.001, respectively). The areas under the receiver operating characteristic curves of the relative power of the delta wave, low-to-high frequency power ratio, and delta-to-alpha ratio were 0.837 (95% confidence interval, 0.737-0.938), 0.835 (0.735-0.934), and 0.768 (0.649-0.887), respectively. The relative power of the delta wave and the two ratios had a positive linear relationship with the peak PAED scores.

CONCLUSIONS

Paediatric patients developing ED have increased low-frequency (delta) frontal EEG activity with reduced high-frequency (alpha and beta) activity during emergence from general anaesthesia.

CLINICAL TRIAL REGISTRATION

NCT03797274.

Effects of Oral Gamma-Aminobutyric Acid (GABA) Administration on Stress and Sleep in Humans: A Systematic Review

Gamma-aminobutyric acid (GABA) is a non-proteinogenic amino acid and is the main inhibitory neurotransmitter in the mammalian brain. GABA's stress-reducing, and sleep enhancing effects have been established. However, although several human clinical trials have been conducted, results regarding the role of natural and/or biosynthetic oral GABA intake on stress and sleep are mixed. We performed a systematic review to examine whether natural and/or biosynthetic oral GABA intake has an effect on stress and sleep. We systematically searched on PubMed database for studies published up to February 2020 following PRISMA guidelines. Only placebo-controlled human trials that assessed stress, sleep, and related psychophysiological outcomes as a response to natural GABA (i.e., GABA that is present naturally in foods) or biosynthetic GABA (i.e., GABA that is produced via fermentation) intake were included. Fourteen studies met the criteria and were included in the systematic review. Although more studies are needed before any inferences can be made about the efficacy of oral GABA consumption on stress and sleep, results show that there is limited evidence for stress and very limited evidence for sleep benefits of oral GABA intake.

Treadmill exercise ameliorates chronic REM sleep deprivation-induced anxiety-like behavior and cognitive impairment in C57BL/6J mice

Various sleep disorders have deleterious effects on mental and cognitive performance. Exercise, as an alternative therapeutic strategy, exerts beneficial impacts on human health. In the present study, we aimed to evaluate the effects of 4 weeks treadmill exercise (4W-TE) on anxiety-like behavior and cognitive performance in mice exposed to 2 months REM sleep deprivation (2M-SD) (20 h per day). Behavioral performance of mice in elevated plus maze test (EPM), open field test (OFT), Y maze test (YM) and Morris water maze test (MWM) was recorded and analyzed 28 h after the last day of sleep deprivation. After behavioral tests, various neurotransmitters including norepinephrine (NE), dopamine (DA), serotonin (5-HT) and γ-aminobutyric acid (GABA) in mouse hippocampus were quantified using high performance liquid chromatography. The hippocampal levels of insulin-like growth factor-1 (IGF-1) and brain derived neurotrophic factor (BDNF) were further detected using ELISA. Behavioral data indicated that 2M-SD exposure induced anxiety-like behaviors and cognitive impairment, as evidenced by the decreased open-arm entries in EPM, reduced central area travels in OFT, declined spontaneous alteration in YM and prolonged escaping latency in MWM. In addition, 2M-SD exposure increased NE and DA, decreased 5-HT and GABA, and reduced IGF-1 and BDNF levels in mouse hippocampus. Interestingly, all these behavioral, neurochemical and neurobiological changes can be ameliorated by 4W-TE training. In summary, these findings confirm the beneficial impacts of exercise on health and provide further experimental evidence for future application of exercise as an alternative therapy against the mental and cognitive problems in patients with sleep disorders.

Vanilla scent reduces frequency of urination in urethane-anesthetized rats

OBJECTIVES

The scent of vanilla has a relaxing effect and is used to treat sleep disorders. Sleep disorders can both cause and be caused by nocturia. Therefore, we examined whether vanilla inhalation would reduce the frequency of urination in rats under light urethane anesthesia.

METHODS

Twenty-four rats were anesthetized with 0.6 g/kg urethane subcutaneously (half the usual dose) to induce a sleep-like state. In 12 rats, continuous cystometry was performed via a transurethral catheter before, during and after inhalation of vanilla (n = 7) or the citrus fruit shiikuwasa (n = 5) for 60 minutes. The remaining 12 rats did not undergo cystometry but underwent vanilla inhalation treatment for 60 minutes (n = 6), or no inhalation treatment (n = 6); blood was then collected from these two groups and serum monoamine levels were compared.

RESULTS

Intervals between bladder contractions were significantly longer after vanilla inhalation than before. However, baseline bladder pressure, maximum bladder contraction pressure, and residual volume remained unchanged. During shiikuwasa inhalation, the body movement of each rat increased but cystometric parameters did not change. Serum concentrations of adrenaline, noradrenaline and dopamine, but not serotonin, were significantly lower in rats that had inhaled vanilla than in those that had not.

CONCLUSIONS

Vanilla scent decreased serum catecholamine levels and urination frequency in rats under light urethane anesthesia. These results suggest that the scent of vanilla may reduce nocturia.

1H MRS Measurement of Cortical GABA and Glutamate in Primary Insomnia and Major Depressive Disorder: Relationship to Sleep Quality and Depression Severity

BACKGROUND

Both Major Depressive Disorder (MDD) and Primary Insomnia (PI) have been linked to deficiencies in cortical γ-aminobutyric acid (GABA) and glutamate (Glu) thus suggesting a shared neurobiological link between these two conditions. The extent to which comorbid insomnia contributes to GABAergic or glutamatergic deficiencies in MDD remains unclear.

METHODS

We used single-voxel proton magnetic resonance spectroscopy (1H MRS) at 4 Tesla to examine GABA+ and Glu relative to creatine (Cr) in the dorsal anterior cingulate cortex (dACC) and in the parieto-occipital cortex (POC) of 51 non-medicated adults with MDD, 24 adults with Primary Insomnia (PI), and 25 age- and sex-matched good sleeper controls (HC). Measures of depression severity and subjective and objective sleep quality were compared with 1H MRS metabolite measures.

RESULTS

MDD subjects exhibited a 15% decrease in Glu/Cr in the dACC compared to HC. Within the MDD group, there was a trend inverse correlation between dACC Glu/Cr and anhedonia ratings. We observed no significant association between measures of sleep quality with dACC Glu/Cr in those with MDD.

LIMITATIONS

The protocol and data interpretation would have been enhanced by the recruitment of MDD subjects with a broader range of affect severity and a more comprehensive assessment of clinical features.

CONCLUSIONS

These findings support the role of cortical glutamatergic mechanisms in the pathophysiology of MDD. Insomnia severity did not further contribute to the relative deficiency of glutamatergic measures in MDD.

Sleep as a Novel Biomarker and a Promising Therapeutic Target for Cerebral Small Vessel Disease: A Review Focusing on Alzheimer's Disease and the Blood-Brain Barrier

Cerebral small vessel disease (CSVD) is a leading cause of cognitive decline in elderly people and development of Alzheimer’s disease (AD). Blood–brain barrier (BBB) leakage is a key pathophysiological mechanism of amyloidal CSVD. Sleep plays a crucial role in keeping health of the central nervous system and in resistance to CSVD. The deficit of sleep contributes to accumulation of metabolites and toxins such as beta-amyloid in the brain and can lead to BBB disruption. Currently, sleep is considered as an important informative platform for diagnosis and therapy of AD. However, there are no effective methods for extracting of diagnostic information from sleep characteristics. In this review, we show strong evidence that slow wave activity (SWA) (0–0.5 Hz) during deep sleep reflects glymphatic pathology, the BBB leakage and memory deficit in AD. We also discuss that diagnostic and therapeutic targeting of SWA in AD might lead to be a novel era in effective therapy of AD. Moreover, we demonstrate that SWA can be pioneering non-invasive and bed–side technology for express diagnosis of the BBB permeability. Finally, we review the novel data about the methods of detection and enhancement of SWA that can be biomarker and a promising therapy of amyloidal CSVD and CSVD associated with the BBB disorders.

Soporific Effect of Modified Suanzaoren Decoction and Its Effects on the Expression of CCK-8 and Orexin-A

Suanzaoren decoction (SZRT), a classic Chinese herbal prescription, has been used as a treatment for insomnia for more than a thousand years. However, recent studies have found no significant effects of SZRT as a treatment for insomnia caused by gastric discomfort. Herein, we studied the effects of modified Suanzaoren decoction (MSZRD) on gastrointestinal disorder-related insomnia. The main constituents of MSZRD were spinosin (2.21 mg/g) and 6-feruloylspinosin (0.78 mg/g). A pentobarbital-induced animal model of insomnia showed that MSZRD shortened sleep latency and prolonged sleep time of the male Institute of Cancer Research (ICR) mice treated for 7 days with oral MSZRD. Sprague-Dawley male rats were treated daily with oral MSZRD or placebo for 11 days and then deprived of sleep for the last 4 days to establish a model of insomnia. Of note, MSZRD-treated animals had significantly improved body weight, organ index scores, and fecal moisture relative to placebo-treated animals, as well as reduced temperature. Sleep-deprived rats exhibited more exploratory behaviors in an open-field anxiety test; however, this effect was significantly reduced in MSZRD-treated animals. We found that MSZRD treatment decreased gastric acid pH, decreased the production of gastrin, pepsin, and Orexin-A, and increased the expression of MTL and CCK-8. Importantly, serum GABA concentration was increased by treatment with MSZRD, as reflected by a decreased Glu/GABA ratio. Treated animals had increased the expression of GAD1, GABARA1, and CCKBR but decreased the expression of Orexin R1. In summary, these results suggest that MSZRD has soporific and gastroprotective effects that may be mediated by differential expression of CCK-8 and Orexin-A.

Altered response to repetitive transcranial magnetic stimulation in patients with chronic primary insomnia

BACKGROUND

We aimed at evaluating the amplitude changes of the motor evoked potentials (MEPs) induced by of low-frequency (LF) repetitive transcranial magnetic stimulation (rTMS) over the primary motor cortex (M1) in10 patients with primary insomnia (PI) and in 10 age-matched healthy controls.

METHODS

Median peak-to-peak MEP amplitudes were assessed in all subjects at three times: at baseline (T₀), after the first train of a single rTMS session (T₁), and after the whole rTMS procedure (T₂). This consists of 20 trains of 1 Hz stimulation with 50 stimuli per train and an intertrain interval of 30 s.

RESULTS

Resting motor threshold (RMT) and MEPs amplitude did not differ between the two groups at T₀. A reduction of MEP size was observed at both T₁ and T₂ in all subjects, but this was significantly less pronounced in patients than in control subjects.

CONCLUSIONS

The lack of MEP inhibition reflects an altered response to LF rTMS in patients with PI. These rTMS findings are indicative of an altered cortical plasticity in inhibitory circuits within M1 in PI. Subjects with PI exhibited an impairment of the LTD-like mechanisms induced by inhibitory rTMS, thus providing further support to the involvement of GABA neurotransmission in the pathophysiology of PI.

The Effects of Dietary Nutrition on Sleep and Sleep Disorders

Sleep disorder significantly affects the life quality of a large number of people but is still an underrecognized disease. Dietary nutrition is believed to play a significant impact on sleeping wellness. Many nutritional supplements have been used trying to benefit sleep wellness. However, the relationship between nutritional components and sleep is complicated. Nutritional factors vary dramatically with different diet patterns and depend significantly on the digestive and metabiotic functions of each individual. Moreover, nutrition can profoundly affect the hormones and inflammation status which directly or indirectly contribute to insomnia. In this review, we summarized the role of major nutritional factors, carbohydrates, lipids, amino acids, and vitamins on sleep and sleep disorders and discussed the potential mechanisms.

Microbiota and Lifestyle: A Special Focus on Diet

It is widely known that a good balance and healthy function for bacteria groups in the colon are necessary to maintain homeostasis and preserve health. However, the lack of consensus on what defines a healthy gut microbiota and the multitude of factors that influence human gut microbiota composition complicate the development of appropriate dietary recommendations for our gut microbiota. Furthermore, the varied response to the intake of probiotics and prebiotics observed in healthy adults suggests the existence of potential inter- and intra-individual factors, which might account for gut microbiota changes to a greater extent than diet. The changing dietary habits worldwide involving consumption of processed foods containing artificial ingredients, such as sweeteners; the coincident rise in emotional disorders; and the worsening of other lifestyle habits, such as smoking habits, drug consumption, and sleep, can together contribute to gut dysbiosis and health impairment, as well as the development of chronic diseases. This review summarizes the current literature on the effects of specific dietary ingredients (probiotics, prebiotics, alcohol, refined sugars and sweeteners, fats) in the gut microbiota of healthy adults and the potential inter- and intra-individual factors involved, as well as the influence of other potential lifestyle factors that are dramatically increasing nowadays.

Anxiolytic-Like Action of Selected 4-(Alkylamino)-3-nitrocoumarin Derivatives in BALB/c Mice

In this work, we explored the possible polypharmacological potential of the already established antimicrobials against gastrointestinal pathogens, 4-(alkylamino)-3-nitrocoumarins, as antianxiety agents, using a battery of in vivo experiments. Three chosen coumarin derivatives, differing in the substituent (sec-butylamino, hexadecylamino, or benzylamino) at position 4, at the doses of 25, 50 and 100 mg kg^-1 , were evaluated in light/dark, open-field, horizontal wire and diazepam-induced sleep models using male BALB/c mice. Depending on the applied dose, all three tested coumarins displayed a noteworthy anxiolytic-like effect. 4-(sec-Butylamino)-3-nitro-2H-chromen-2-one and 4-(hexadecylamino)-3-nitro-2H-chromen-2-one could be recognized as true anxiolytics in the lowest applied dose, based on three tests, without exerting any sedative effects. Thus, the 3-nitrocoumarin core deserves further chemical diversity exploration in the 'antianxiety' direction.

Analysis of genes within the schizophrenia-linked 22q11.2 deletion identifies interaction of night owl/LZTR1 and NF1 in GABAergic sleep control

The human 22q11.2 chromosomal deletion is one of the strongest identified genetic risk factors for schizophrenia. Although the deletion spans a number of known genes, the contribution of each of these to the 22q11.2 deletion syndrome (DS) is not known. To investigate the effect of individual genes within this interval on the pathophysiology associated with the deletion, we analyzed their role in sleep, a behavior affected in virtually all psychiatric disorders, including the 22q11.2 DS. We identified the gene LZTR1 (night owl, nowl) as a regulator of night-time sleep in Drosophila. In humans, LZTR1 has been associated with Ras-dependent neurological diseases also caused by Neurofibromin-1 (Nf1) deficiency. We show that Nf1 loss leads to a night-time sleep phenotype nearly identical to that of nowl loss and that nowl negatively regulates Ras and interacts with Nf1 in sleep regulation. Furthermore, nowl is required for metabolic homeostasis, suggesting that LZTR1 may contribute to the genetic susceptibility to obesity associated with the 22q11.2 DS. Knockdown of nowl or Nf1 in GABA-responsive sleep-promoting neurons elicits the sleep phenotype, and this defect can be rescued by increased GABA_A receptor signaling, indicating that Nowl regulates sleep through modulation of GABA signaling. Our results suggest that nowl/LZTR1 may be a conserved regulator of GABA signaling important for normal sleep that contributes to the 22q11.2 DS.

Schizophrenia is a devastating mental disorder with a large genetic component to disease predisposition. One of the strongest genetic risk factors for this disorder is a relatively small genetic deletion of 43 genes on the 22^nd chromosome, called 22q11.2, which confers about a 25% risk of schizophrenia development. However, it is likely that only some of these deleted genes affect disease risk, so we tested most of them individually. One of the main symptoms of schizophrenia is disturbed sleep. Sleep is an evolutionarily conserved behavior that can be easily studied in the fruit fly Drosophila melanogaster, so we investigated the effect on sleep of blocking expression of the fly homologs of most of the 22q11.2 genes and identified the gene LZTR1 (night owl, nowl) as an important sleep regulator. We found that Nowl/LZTR1 is required for inhibition of the Ras pathway and interacts genetically with the Ras inhibitor NF1. Nowl/LZTR1 appears to function in sleep by modulating inhibitory GABA signaling, which is affected in schizophrenia. Thus, this gene may underlie some of the phenotypes of the human schizophrenia-risk deletion.

Alteration of metabolic profiles in Lemna paucicostata culture and enhanced production of GABA and ferulic acid by ethephon treatment

Lemna species have been used in the food, feed, and pharmaceutical industries, as they are inexpensive sources of proteins, starches, and fatty acids. In this study, we treated L. paucicostata with different concentrations (0.05, 0.1, 0.2, 0.5, or 1 mM) of ethephon. The total dry weight decreased in all ethephon-treated groups compared to the control group. We also investigated the alteration of metabolic profiles induced by ethephon treatment by using gas chromatography-mass spectrometry. This analysis identified 48 metabolites, and the relative levels of most of alcohols, amino acids, fatty acids, and phenols increased by the ethephon treatment, whereas levels of organic acids and sugars decreased. Among these, the highest production of γ-aminobutyric acid (GABA, 5.041 ± 1.373 mg/L) and ferulic acid (0.640 ± 0.071 mg/L) was observed in the 0.5 mM and the 0.2 mM ethephon treatment groups, respectively. These results could be useful for large-scale culture of L. paucicostata with enhanced GABA and ferulic acid content for utilization in the food, feed, cosmetic, and pharmaceutical industries.

Melatonin effects on EEG activity during non-rapid eye movement sleep in mild-to-moderate Alzheimer´s disease: a pilot study

INTRODUCTION

There is evidence to suggest that melatonin diminishes non-rapid eye movement sleep (NREMS) latency in patients with Alzheimer´s disease (AD). However, melatonin's effects on cortical activity during NREMS in AD have not been studied. The objective of this research was to analyze the effects of melatonin on cortical activity during the stages of NREMS in 8 mild-to-moderate AD patients that received 5-mg of fast-release melatonin.

METHODS

During a single-blind, placebo-controlled crossover study, polysomnographic recordings were obtained from C3-A1, C4-A2, F7-T3, F8-T4, F3-F4 and O1-O2. Also, the relative power (RP) and EEG coherences of the delta, theta, alpha1, alpha2, beta1, beta2 and gamma bands were calculated during NREMS-1, NREMS-2 and NREMS-3. These sleep latencies and all EEG data were then compared between the placebo and melatonin conditions.

RESULTS

During NREMS-2, a significant RP increase was observed in the theta band of the left-central hemisphere. During NREMS-3, significant RP decreases in the beta bands were recorded in the right-central hemisphere, compared to the placebo group. After melatonin administration, significant decreases of EEG coherences in the beta2, beta1 and gamma bands were observed in the right hemisphere during NREMS-3.

DISCUSSION

We conclude that short NREMS onset related to melatonin intake in AD patients is associated with a significant RP increase in the theta band and a decrease in RP and EEG coherences in the beta and gamma bands during NREMS-3. These results suggest that the GABAergic pathways are preserved in mild-to-moderate AD.

A randomized controlled pilot study of the effectiveness of magnolia tea on alleviating depression in postnatal women

The magnolia tea has been used in traditional oriental medicine for multiple purposes including sleep aid. Postpartum depression is a mental illness that adversely affects the health and well-being of many families with newborns. Given the known effectiveness and relative safety, herein we aimed to investigate whether magnolia tea has a palliative effect on postpartum depression. The qualified participants were randomly assigned to the intervention group or the control group. The participants in the intervention group drunk magnolia tea, while the control group received regular postpartum care only. The outcome variables including Postpartum Sleep Quality Scale (PSQS), Edinburgh Postnatal Depression Scale (EPDS), and Postpartum Fatigue Scale (PFS) were assessed and compared. In comparison with the control group, the intervention group demonstrated significant difference for physical-symptom-related sleep inefficiency (PSQS Factor 2) at 3 weeks post-test (t = -2.10, p = .03). The comparison results also revealed significant differences for PFS at both 3 weeks post-test (t = -2.02, p = .04) and 6 weeks post-test (t = -1.99, p = .04). Further, magnolia tea intervention significantly alleviated the symptoms of depression, reflected by the EPDS scores at 3 weeks post-test (t = -2.38, p = .02) and 6 weeks post-test (t = -2.13, p = .02). Our trial results suggested that drinking single-ingredient magnolia tea for a 3-week duration has positive effects on postpartum women. Magnolia tea is recommended as a supplementary approach to ameliorate sleep quality of postpartum women, while alleviating their symptoms of depression.

Shorter sleep duration is associated with lower GABA levels in the anterior cingulate cortex

BACKGROUND

Alterations in the levels of gamma-aminobutyric acid (GABA) and glutamate + glutamine (Glx), which are major inhibitory and excitatory neurotransmitters, respectively, are frequently associated with insomnia. Previous reports also suggested the involvement of the anterior cingulate cortex (ACC) and medial prefrontal cortex (mPFC) in insomnia and shorter sleep duration. In the current study, we investigated whether the GABA and Glx levels were altered in the ACC/mPFC in subclinical insomnia while focusing on the sleep duration.

METHODS

We examined levels of GABA and Glx in the ACC/mPFC of the brain with magnetic resonance spectroscopy in 166 individuals with subjective sleep complaints but without a diagnosis of insomnia. Participants were divided into two groups according to sleep duration (≥6 h/night: n = 79 vs. < 6 h/night: n = 74), which was measured using a wrist-worn actigraphy. Working memory function and overall subjective sleep quality were assessed with a computerized neuropsychological test and self-report questionnaire, respectively.

RESULTS

GABA levels in the ACC/mPFC were lower in the shorter sleep duration group relative to the longer sleep duration group (t = -2.21, p = 0.03). Glx levels did not differ between the two groups (t = -0.20, p = 0.84). Lower GABA levels were associated with lower spatial working memory performance in the shorter sleep duration group (β = -0.21, p = 0.03), but not the longer sleep duration group (β = 0.04, p = 0.72).

CONCLUSION

Shorter sleep duration was associated with lower GABA levels in the ACC/mPFC. These findings may provide insight into the underlying mechanisms of impaired working memory function related to insomnia and sleep loss.

Hyperarousal Is Associated with Socioemotional Processing in Individuals with Insomnia Symptoms and Good Sleepers

Despite complaints of difficulties in waking socioemotional functioning by individuals with insomnia, only a few studies have investigated emotion processing performance in this group. Additionally, the role of sleep in socioemotional processing has not been investigated extensively nor using quantitative measures of sleep. Individuals with insomnia symptoms (n = 14) and healthy good sleepers (n = 15) completed two nights of at-home polysomnography, followed by an afternoon of in-lab performance testing on tasks measuring the processing of emotional facial expressions. The insomnia group self-reported less total sleep time, but no other group differences in sleep or task performance were observed. Greater beta EEG power throughout the night was associated with higher intensity ratings of happy, fearful and sad faces for individuals with insomnia, yet blunted sensitivity and lower accuracy for good sleepers. Thus, the presence of hyperarousal differentially impacted socioemotional processing of faces in individuals with insomnia symptoms and good sleepers.

Potential Mechanisms Involved in the Anticonvulsant Effect of Methanol Extract of Pyrenancantha staudtii in Mice

OBJECTIVE

To determine the potential effect of Pyrenancantha staudtii extract on experimentally induced seizures in mice and to evaluate the role of benzodiazepines, naloxone, and serotonin within these pathways.

METHODS

Animal behaviours were evaluated using open field, hexobarbitone-induced sleep model, and anticonvulsant activity using picrotoxin-, or strychnine-, or isoniazid-induced convulsions. Attempt to understand the mode of action of the anticonvulsant activity of the plant, three notable antagonists (flumazenil, 3 mg/kg; naloxone 5 mg/kg, i.p., and cyproheptadine, 4 mg/kg, i.p) were used.

RESULTS

The results revealed a significant (p < 0.05) reduction in the frequency of rearing and grooming episodes compared with the control. The extract of P. staudtii potentiates the sleeping time of hexobarbitone-induced hypnosis in a dose-related manner. P. staudtii stem bark extracts significantly (p<0.05) prolonged the onset of a seizure and attenuated the duration of seizure in a dose-dependent manner in picrotoxin- and or isoniazid-induced seizures. While, P. staudtii stem bark extract at all doses (100, 200, and 400 mg kg-1) though significantly prolonged the onset of action, but did not confer any significant changes on the duration, as well as mortality in this strychnine-induced seizure model. However, the anticonvulsant activity of the methanolic extract of P. staudtii was significantly reversed following intraperitoneal pre-treatment with flumazenil (GABA receptor antagonist) and naloxone (opioid receptor antagonist) but not cyproheptadine (5-HT2 receptor antagonist) in picrotoxin-induced convulsion.

CONCLUSION

The data obtained suggest that methanol extract of P. staudtii possessed significant anticonvulsant effect, thereby confirming the traditional uses of P. staudtii in the treatment of epilepsy; mechanisms of which could involve the interaction with GABAergic and or opioidergic system.

Suprachiasmatic lesions restore object recognition in down syndrome model mice

The Ts65Dn mouse is a well-studied model of trisomy 21, Down syndrome. This mouse strain has severe learning disability as measured by several rodent learning tests that depend on hippocampal spatial memory function. Hippocampal long-term potentiation (LTP) is deficient in these mice. Short-term daily treatment with low-dose GABA receptor antagonists rescue spatial learning and LTP in Ts65Dn mice leading to the hypothesis that the learning disability is due to GABAergic over-inhibition of hippocampal circuits. The fact that the GABA receptor antagonists were only effective if delivered during the daily light phase suggested that the source of the excess GABA was controlled directly or indirectly by the circadian system. The central circadian pacemaker of mammals is the suprachiasmatic nucleus (SCN), which is largely a GABAergic nucleus. In this study we investigated whether elimination of the SCN in Ts65Dn mice would restore their ability to form recognition memories as tested by the novel object recognition (NOR) task. Full, but not partial lesions of the SCN of Ts65Dn mice normalized their ability to perform on the NOR test. These results suggest that the circadian system modulates neuroplasticity over the time frame involved in the process of consolidation of recognition memories.

Intraperitoneal injection of ginkgolide B, a major active compound of Ginkgo biloba, dose-dependently increases the amount of wake and decreases non-rapid eye movement sleep in C57BL/6 mice

The terpene lactones of Ginkgo biloba extract, namely ginkgolides (A, B, and C) and bilobalide, possess antioxidant, anti-inflammatory, and neuroprotective effects. They are widely prescribed for the treatment of cerebral dysfunctions and neurological impairments. In addition, they demonstrate antagonistic action at the gamma-aminobutyric acid type A and glycine receptors, which are members of the ligand-gated ion channel superfamily. In the present study, the effects of ginkgolides (A, B, and C) and bilobalide on sleep in C57BL/6 mice were investigated. Ginkgolide B was found to dose-dependently increase the amount of wake and decrease that of non-rapid eye movement sleep without changes in the electroencephalography power density of each sleep/wake stage, core body temperature and locomotor activity for the first 6 h after intraperitoneal injection. Of note, the amount of wake after injection of 5 mg/kg of ginkgolide B showed a significant increase (14.9 %) compared with that of vehicle (P = 0.005). In contrast, there were no significant differences in the amount of sleep, core body temperature, and locomotor activity in the mice injected with ginkgolide A and C. Bilobalide briefly induced a decrease in locomotor activity but did not exert significant effects on the amounts of sleep and wake. The modes of action of the wake-enhancing effects of ginkgolide B are unknown. However, it may act through the antagonism of gamma-aminobutyric acid type A and glycine receptors because it is established that these inhibitory amino acids mediate sleep and sleep-related physiology. It is of interest to further evaluate the stimulant and awaking actions of ginkgolide B on the central nervous system in clinical and basic research studies.

Blood signatures for second stage human African trypanosomiasis: a transcriptomic approach

BACKGROUND

Rhodesiense sleeping sickness is caused by infection with T. b rhodesiense parasites resulting in an acute disease that is fatal if not treated in time. The aim of this study was to understand the global impact of active T. b rhodesiense infection on the patient's immune response in the early and late stages of the disease.

METHODS

RNASeq was carried out on blood and cerebral spinal fluid (CSF) samples obtained from T. b. rhodesiense infected patients. The control samples used were from healthy individuals in the same foci. The Illumina sequenced reads were analysed using the Tuxedo suite pipeline (Tophat, Cufflinks, Cuffmerge, Cuffdiff) and differential expression analysis carried out using the R package DESeq2. The gene enrichment and function annotation analysis were done using the ToppCluster, DAVID and InnateDB algorithms.

RESULTS

We previously described the transcriptomes of T. b rhodesiense from infected early stage blood (n = 3) and late stage CSF (n = 3) samples from Eastern Uganda. We here identify human transcripts that were differentially expressed (padj < 0.05) in the early stage blood versus healthy controls (n = 3) and early stage blood versus late stage CSF. Differential expression in infected blood showed an enrichment of innate immune response genes whereas that of the CSF showed enrichment for anti-inflammatory and neuro-degeneration signalling pathways. We also identified genes (C1QC, MARCO, IGHD3-10) that were up-regulated (log₂ FC > 2.5) in both the blood and CSF.

CONCLUSION

The data yields insights into the host's response to T. b rhodesiense parasites in the blood and central nervous system. We identified key pathways and signalling molecules for the predominant innate immune response in the early stage infection; and anti-inflammatory and neuro-degeneration pathways associated with sleep disorders in second stage infection. We further identified potential blood biomarkers that can be used for diagnosis of late stage disease without the need for lumbar puncture.

Antidepressive Mechanisms of Probiotics and Their Therapeutic Potential

The accumulating knowledge of the host-microbiota interplay gives rise to the microbiota-gut-brain (MGB) axis. The MGB axis depicts the interkingdom communication between the gut microbiota and the brain. This communication process involves the endocrine, immune and neurotransmitters systems. Dysfunction of these systems, along with the presence of gut dysbiosis, have been detected among clinically depressed patients. This implicates the involvement of a maladaptive MGB axis in the pathophysiology of depression. Depression refers to symptoms that characterize major depressive disorder (MDD), a mood disorder with a disease burden that rivals that of heart diseases. The use of probiotics to treat depression has gained attention in recent years, as evidenced by increasing numbers of animal and human studies that have supported the antidepressive efficacy of probiotics. Physiological changes observed in these studies allow for the elucidation of probiotics antidepressive mechanisms, which ultimately aim to restore proper functioning of the MGB axis. However, the understanding of mechanisms does not yet complete the endeavor in applying probiotics to treat MDD. Other challenges remain which include the heterogeneous nature of both the gut microbiota composition and depressive symptoms in the clinical setting. Nevertheless, probiotics offer some advantages over standard pharmaceutical antidepressants, in terms of residual symptoms, side effects and stigma involved. This review outlines antidepressive mechanisms of probiotics based on the currently available literature and discusses therapeutic potentials of probiotics for depression.

Neurochemical mechanisms for memory processing during sleep: basic findings in humans and neuropsychiatric implications

Sleep is essential for memory formation. Active systems consolidation maintains that memory traces that are initially stored in a transient store such as the hippocampus are gradually redistributed towards more permanent storage sites such as the cortex during sleep replay. The complementary synaptic homeostasis theory posits that weak memory traces are erased during sleep through a competitive down-selection mechanism, ensuring the brain's capability to learn new information. We discuss evidence from neuropharmacological experiments in humans to show how major neurotransmitters and neuromodulators are implicated in these memory processes. As to the major excitatory neurotransmitter glutamate that plays a prominent role in inducing synaptic consolidation, we show that these processes, while strengthening cortical memory traces during sleep, are insufficient to explain the consolidation of hippocampus-dependent declarative memories. In the inhibitory GABAergic system, we will offer insights how drugs may alter the intricate interplay of sleep oscillations that have been identified to be crucial for strengthening memories during sleep. Regarding the dopaminergic reward system, we will show how it is engaged during sleep replay, but that dopaminergic neuromodulation likely plays a side role for enhancing relevant memories during sleep. Also, we briefly go into basic evidence on acetylcholine and cortisol whose low tone during slow wave sleep (SWS) is crucial in supporting hippocampal-to-neocortical memory transmission. Finally, we will outline how these insights can be used to improve treatment of neuropsychiatric disorders focusing mainly on anxiety disorders, depression, and addiction that are strongly related to memory processing.

Effects of Passiflora incarnata Linnaeus on polysomnographic sleep parameters in subjects with insomnia disorder: a double-blind randomized placebo-controlled study

The purpose of the present double-blind randomized placebo-controlled clinical study was to investigate the effects of Passionflower on polysomnographic sleep parameters in subjects with insomnia disorder. A total number 110 adult participants (mean age = 40.47 ± 11.68, Female = 53.6%) met the inclusion criteria of insomnia disorder according to the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders). After randomization, patients received either the Passionflower extract or the placebo for 2 weeks. Patients underwent an overnight polysomnography and completed sleep diaries, Insomnia Severity Index, and Pittsburgh Sleep Quality Index. Within group comparisons were analyzed with paired t-tests or Wilcoxon's signed rank tests, and between-group comparisons were analyzed with independent t-tests or Mann-Whitney U Tests, as appropriate. Total sleep time (TST) was significantly increased in the Passionflower group compared with placebo (Passionflower vs placebo, 23.05 ± 54.26 vs -0.16 ± 53.12; P = 0.049). Sleep efficiency and wake after sleep onset (WASO) significantly improved after 2 weeks in the Passionflower group but there was no difference compared with the placebo group. The current study demonstrated the positive effects of Passionflower on objective sleep parameters including TST on polysomnography in adults with insomnia disorder. Further study is needed to investigate the clinical efficacy of Passionflower on insomnia.

GABA and l-theanine mixture decreases sleep latency and improves NREM sleep

CONTEXT

γ-Aminobutyric acid (GABA) is the main inhibitory neurotransmitter and it is well established that activation of GABA_A receptors favours sleep. l-Theanine, a naturally occurring amino acid first discovered in green tea, is a well-known anti-anxiety supplement with proven relaxation benefits.

OBJECTIVE

This study investigated the potential synergistic sleep enhancement effect of GABA/l-theanine mixture.

MATERIALS AND METHODS

Pentobarbital-induced sleep test was applied to find proper concentration for sleep-promoting effect in ICR mice. Electroencephalogram (EEG) analysis was performed to investigate total sleeping time and sleep quality in normal SD rats and caffeine-induced awareness model. Real-time polymerase chain reaction (RT-PCR) was applied to investigate whether the sleep-promoting mechanism of GABA/l-theanine mixture involved transcriptional processes.

RESULTS

GABA/l-theanine mixture (100/20 mg/kg) showed a decrease in sleep latency (20.7 and 14.9%) and an increase in sleep duration (87.3 and 26.8%) compared to GABA or theanine alone. GABA/l-theanine mixture led to a significant increase in rapid eye movement (REM) (99.6%) and non-REM (NREM) (20.6%) compared to controls. The use of GABA/l-theanine mixture rather than GABA or l-theanine alone restored to normal levels sleep time and quality in the arousal animal model. The administration of GABA/l-theanine led to increased expression of GABA and the glutamate GluN1 receptor subunit.

CONCLUSIONS

GABA/l-theanine mixture has a positive synergistic effect on sleep quality and duration as compared to the GABA or l-theanine alone. The increase in GABA receptor and GluN1 expression is attributed to the potential neuromodulatory properties of GABA/l-theanine combination, which seems to affect sleep behaviour.

Sleep-behaviour relationship in children with autism spectrum disorder: methodological pitfalls and insights from cognition and sensory processing

Sleep disturbances are frequent and varied in autism spectrum disorder (ASD). Growing evidence suggests that sleep problems in children with ASD are driven by their clinical characteristics and psychiatric comorbidities. Therefore, the wide range of reported sleep disturbances reflects the marked heterogeneity of clinical pictures in ASD. Whether sleep disturbances and their various forms may, in turn, account for at least part of the phenotypical variability of ASD is a crucial question discussed in this review. We first outline studies both validating and challenging a bidirectional theoretical framework for sleep disorders in children with ASD. We then propose to extend this model by including cognition and sensory processing as key factors in the vicious circle linking sleep disorders and autistic symptoms. WHAT THIS PAPER ADDS: There is a bidirectional interplay between autism symptoms and sleep disturbances. Sleep influence on daytime cognitive and sensory skills should be further investigated.

Sedative and hypnotic effects of compound Anshen essential oil inhalation for insomnia

BACKGROUNDS

The chemical composition of many essential oils indicates that they have sedative and hypnotic effects, but there is still a lack of systematic studies on the sedative and hypnotic effects of essential oils. In addition, aromatherapy does not seem to have the side effects of many traditional psychotropic substances, which is clearly worthwhile for further clinical and scientific research. The clinical application of essential oils in aromatherapy has received increasing attention, and detailed studies on the pharmacological activities of inhaled essential oils are increasingly needed.

HYPOTHESIS/PURPOSE

As insomniacs are usually accompanied by symptoms of depression and anxiety of varying degrees, based on the theory of aromatherapy of Traditional Chinese Medicine, this experiment is to study a Compound Anshen essential oil that is compatible with Lavender essential oil, Sweet Orange essential oil, Sandalwood essential oil and other aromatic medicine essential oils with sedative and hypnotic effects, anti-anxiety and anti-depression effects. To study the sedative and hypnotic effects of Compound Anshen essential oil inhaled and the main chemical components of Compound Anshen essential oil, and to compare and analyze the pharmacodynamics of diazepam, a commonly used drug for insomnia.

METHODS

The Open field test and Pentobarbital-induced sleep latency and sleep time experiments were used to analyze and compare the sedative and hypnotic effects of inhaling Compound Anshen essential oil and the administration of diazepam on mice. The changes of 5-HT and GABA in mouse brain were analyzed by Elisa. The main volatile constituents of Compound Anshen essential oil were analyzed by gas chromatography-mass spectrometry (GC-MS).

RESULTS

Inhalation of Compound Anshen essential oil can significantly reduce the spontaneous activity of mice, reduce latency of sleeping time and prolong duration of sleeping time. The results of enzyme-linked immunosorbent assay showed that Compound Anshen essential oil can increase the content of 5-HT and GABA in mouse brain. The main volatile chemical constituents of the Compound Anshen essential oil are D-limonene (24.07%), Linalool (21.98%), Linalyl acetate (15.37%), α-Pinene (5.39%), and α-Santalol (4.8%).

CONCLUSION

The study found that the inhalation of Compound Anshen essential oil has sedative and hypnotic effect. This study provides a theoretical basis for further research and development of the sedative and hypnotic effects of Compound Anshen essential oil based on the theory of aromatherapy.

Gut microbiome diversity is associated with sleep physiology in humans

The human gut microbiome can influence health through the brain-gut-microbiome axis. Growing evidence suggests that the gut microbiome can influence sleep quality. Previous studies that have examined sleep deprivation and the human gut microbiome have yielded conflicting results. A recent study found that sleep deprivation leads to changes in gut microbiome composition while a different study found that sleep deprivation does not lead to changes in gut microbiome. Accordingly, the relationship between sleep physiology and the gut microbiome remains unclear. To address this uncertainty, we used actigraphy to quantify sleep measures coupled with gut microbiome sampling to determine how the gut microbiome correlates with various measures of sleep physiology. We measured immune system biomarkers and carried out a neurobehavioral assessment as these variables might modify the relationship between sleep and gut microbiome composition. We found that total microbiome diversity was positively correlated with increased sleep efficiency and total sleep time, and was negatively correlated with wake after sleep onset. We found positive correlations between total microbiome diversity and interleukin-6, a cytokine previously noted for its effects on sleep. Analysis of microbiome composition revealed that within phyla richness of Bacteroidetes and Firmicutes were positively correlated with sleep efficiency, interleukin-6 concentrations and abstract thinking. Finally, we found that several taxa (Lachnospiraceae, Corynebacterium, and Blautia) were negatively correlated with sleep measures. Our findings initiate linkages between gut microbiome composition, sleep physiology, the immune system and cognition. They may lead to mechanisms to improve sleep through the manipulation of the gut microbiome.

A Library Screening Strategy Combining the Concepts of MS Binding Assays and Affinity Selection Mass Spectrometry

The primary objective of early drug development is to identify hits and leads for a target of interest. To achieve this aim, rapid, and reliable screening techniques for a huge number of compounds are needed. Mass spectrometry based binding assays (MS Binding Assays) represent a well-established technique for library screening based on competitive binding experiments revealing active sublibraries due to reduced binding of a reporter ligand and following hit identification for active libraries by deconvolution in further competitive binding experiments. In the present study, we combined the concepts of MS Binding Assays and affinity selection mass spectrometry (ASMS) to improve the efficiency of the hit identification step. In that case, only a single competitive binding experiment is performed that is in the first step analyzed for reduced binding of the reporter ligand and—only if a sublibrary is active—additionally for specific binding of individual library components. Subsequently, affinities of identified hits as well as activities of reduced sublibraries (i.e., all sublibrary components without hit) are assessed in additional competitive binding experiments. We exemplified this screening concept for the identification of ligands addressing the most widespread GABA transporter subtype in the brain (GAT1) studying in the beginning a library composed of 128 and further on a library of 1,280 well-characterized GAT1 inhibitors, drug substances, and pharmacological tool compounds. Determination of sublibraries' activities was done by quantification of bound NO711 as reporter ligand and hit identification for the active ones achieved in a further LC-ESI-MS/MS run in the multiple reaction monitoring mode enabling detection of all sublibrary components followed by hit verification and investigation of reduced sublibraries in further competitive binding experiments. In this way, we could demonstrate that all GAT1 inhibitors reducing reporter ligand binding below 50% at a concentration of 1 μM are detected reliably without generation of false positive or false negative hits. As the described strategy is apart from its reliability also highly efficient, it can be assumed to become a valuable tool in early drug research, especially for membrane integrated drug targets that are often posing problems in established screening techniques.

Fatigue, Sleep, and Autoimmune and Related Disorders

Profound and debilitating fatigue is the most common complaint reported among individuals with autoimmune disease, such as systemic lupus erythematosus, multiple sclerosis, type 1 diabetes, celiac disease, chronic fatigue syndrome, and rheumatoid arthritis. Fatigue is multi-faceted and broadly defined, which makes understanding the cause of its manifestations especially difficult in conditions with diverse pathology including autoimmune diseases. In general, fatigue is defined by debilitating periods of exhaustion that interfere with normal activities. The severity and duration of fatigue episodes vary, but fatigue can cause difficulty for even simple tasks like climbing stairs or crossing the room. The exact mechanisms of fatigue are not well-understood, perhaps due to its broad definition. Nevertheless, physiological processes known to play a role in fatigue include oxygen/nutrient supply, metabolism, mood, motivation, and sleepiness-all which are affected by inflammation. Additionally, an important contributing element to fatigue is the central nervous system-a region impacted either directly or indirectly in numerous autoimmune and related disorders. This review describes how inflammation and the central nervous system contribute to fatigue and suggests potential mechanisms involved in fatigue that are likely exhibited in autoimmune and related diseases.

An Updated Review on Pharmaceutical Properties of Gamma-Aminobutyric Acid

Gamma-aminobutyric acid (Gaba) is a non-proteinogenic amino acid that is widely present in microorganisms, plants, and vertebrates. So far, Gaba is well known as a main inhibitory neurotransmitter in the central nervous system. Its physiological roles are related to the modulation of synaptic transmission, the promotion of neuronal development and relaxation, and the prevention of sleeplessness and depression. Besides, various pharmaceutical properties of Gaba on non-neuronal peripheral tissues and organs were also reported due to anti-hypertension, anti-diabetes, anti-cancer, antioxidant, anti-inflammation, anti-microbial, anti-allergy, hepato-protection, reno-protection, and intestinal protection. Therefore, Gaba may be considered as potential alternative therapeutics for prevention and treatment of various diseases. Accordingly, this updated review was mainly focused to describe the pharmaceutical properties of Gaba as well as emphasize its important role regarding human health.

Jujuboside A prevents sleep loss-induced disturbance of hippocampal neuronal excitability and memory impairment in young APP/PS1 mice

Sleep deprivation (SD) is the hallmark of modern society and may increase risk of Alzheimer's disease (AD). However, it is unclear how SD facilitates early cognitive impairments observed in AD models, as the underlying molecular mechanism is largely unknown. Here, we aim to investigate SD-induced cellular and molecular alterations in hippocampus of young APP/PS1 mice and whether jujuboside A (JuA) treatment could negate these alterations. Our results reveal that although SD causes spatial memory impairments in both genotypes, SD decreases frequency and amplitude of mEPSCs and pCREB levels in WT, but increases frequency and amplitude of mEPSCs, NMDAR, GluR1, pCaMKII (β, α) and decreases CREB levels in APP/PS1 mice, implicating that SD may facilitate abnormalities in young APP/PS1 mice via enhancing neuronal excitability. Moreover, JuA suppresses SD-induced enhancement of mEPSCs and prevents memory impairment in APP/PS1 mice. Further, whole-cell puff experiment suggests that JuA may function to activate GABAergic inhibition to reduce SD-induced enhancement of excitatory synaptic transmission in APP/PS1 mice. The present study reveals that sleep loss induces spatial memory impairment in an AD mouse model by disrupting the excitatory signaling pathway, and JuA prevents this via GABAergic mechanism.

The Effect of sequential bilateral low-frequency rTMS over dorsolateral prefrontal cortex on serum level of BDNF and GABA in patients with primary insomnia

OBJECTIVE

This study aimed to investigate the effect of sequential bilateral low-frequency repetitive transcranial magnetic stimulation (rTMS) over dorsolateral prefrontal cortex (DLPFC) on patients with primary insomnia (PI).

METHODS

A total of 32 eligible right-handed participants diagnosed by PI according to International classification of sleep disorders (ICD-3) were recruited into this study. Participants received 10 daily sessions of sequential bilateral 1 Hz rTMS over DLPFC. Before and after the whole procedure of rTMS, patients were assessed by Pittsburgh Sleep Quality Index (PSQI) for the severity of sleep disturbance. Meanwhile, serum concentration of brain-derived neurotrophic factor (BDNF) and gamma-aminobutyric acid (GABA) in patients was measured by ELISA and UPLC, respectively. Moreover, the amplitude of MEPs reflecting the right cortical excitability was examined. Finally, Pearson correlation analysis was performed to evaluate the correlation among the change of these variables.

RESULTS

After rTMS treatment, the PSQI score was markedly decreased as compared to pre-rTMS; the concentrations of serum BDNF and GABA were significantly higher; the amplitude of MEPs was markedly reduced. Pearson correlation analysis revealed that the change of PSQI score was negatively associated with the alteration of serum BDNF level and serum GABA level, and positively associated with the change of MEPs amplitude; the change of MEPs amplitude was negatively associated with fold change in the serum BDNF level and the serum GABA level; the increase in serum GABA level was positively associated with the serum BDNF level.

CONCLUSIONS

A sequential bilateral low-frequency rTMS over DLPFC significantly improves primary insomnia probably by increasing the level of BDNF and GABA in the brain and reducing cortical excitability.

Fragile X-Associated Neuropsychiatric Disorders (FXAND)

Fragile X syndrome (FXS) is caused by the full mutation (>200 CGG repeats) in the Fragile X Mental Retardation 1 (FMR1) gene. It is the most common inherited cause of intellectual disability (ID) and autism. This review focuses on neuropsychiatric disorders frequently experienced by premutation carriers with 55 to 200 CGG repeats and the pathophysiology involves elevated FMR1 mRNA levels, which is different from the absence or deficiency of fragile X mental retardation protein (FMRP) seen in FXS. Neuropsychiatric disorders are the most common problems associated with the premutation, and they affect approximately 50% of individuals with 55 to 200 CGG repeats in the FMR1 gene. Neuropsychiatric disorders in children with the premutation include anxiety, ADHD, social deficits, or autism spectrum disorders (ASD). In adults with the premutation, anxiety and depression are the most common problems, although obsessive compulsive disorder, ADHD, and substance abuse are also common. These problems are often exacerbated by chronic fatigue, chronic pain, fibromyalgia, autoimmune disorders and sleep problems, which are also associated with the premutation. Here we review the clinical studies, neuropathology and molecular underpinnings of RNA toxicity associated with the premutation. We also propose the name Fragile X-associated Neuropsychiatric Disorders (FXAND) in an effort to promote research and the use of fragile X DNA testing to enhance recognition and treatment for these disorders.

Fiprole insecticide resistance of Laodelphax striatellus: electrophysiological and molecular docking characterization of A2'N RDL GABA receptors

BACKGROUND

Phenylpyrazole (fiprole) insecticides, including ethiprole, fipronil and flufiprole with excellent activity on rice planthoppers, are very important in Asia but resistance has developed after decades of use. The molecular mechanism of fipronil- but not ethiprole-resistance has been previously studied in rice planthoppers. In our laboratory, a small brown planthopper Laodelphax striatellus strain with ethiprole-resistance was cultured and the molecular mechanisms of ethiprole resistance and of cross-resistance among fiprole insecticides were investigated.

RESULTS

Ethiprole-resistant L. striatellus has >5000-fold resistance compared to the susceptible strain, and exhibits around 200-fold cross-resistance with fipronil and flufiprole. RDL genes were isolated from susceptible and ethiprole-resistant L. striatellus and expressed in Xenopus oocytes. Electrophysiological studies showed fiprole insecticides inhibited γ-aminobutyric acid (GABA)-induced current with IC₅₀ = 0.1-1.4 μM to LsRDL-S homomers. In LsRDL-R with A2'N mutation, only 1-13% inhibition was observed on treatment with 10 μM ethiprole, fipronil or flufiprole. Homology models indicate A2'N mutation allows crosslinking hydrogen bonding between Asn sidechains at the 2' position around the channel pore, blocking insecticides from interacting near this position. In contrast, insecticides showed favorable binding near A2' in wild-type L. striatellus.

CONCLUSION

Cross-resistance is increasing for fiprole insecticides in L. striatellus and management strategies are necessary to minimize resistance. © 2018 Society of Chemical Industry.