Anxiety disorders and GABA neurotransmission: a disturbance of modulation

Synthesis of versatile neuromodulatory molecules by a gut microbial glutamate decarboxylase

Dysbiosis of the microbiome correlates with many neurological disorders, yet very little is known about the chemistry that controls the production of neuromodulatory molecules by gut microbes. Here, we found that an enzyme glutamate decarboxylase (BfGAD) of a gut microbe Bacteroides fragilis forms multiple neuromodulatory molecules such as γ-aminobutyric acid (GABA), hypotaurine, taurine, homotaurine, and β-alanine. We evolved BfGAD and doubled its taurine productivity. Additionally, we increased its specificity toward the substrate L-glutamate. Here, we provide a chemical strategy via which the BfGAD activity could be fine-tuned. In future, this strategy could be used to modulate the production of neuromodulatory molecules by gut microbes.

Exogenous GABA Alleviates Tourette Syndrome-Like Behavior in Sprague-Dawley Rats by Altering Gut Microbiota and Striatum Metabolism

Context

Tourette syndrome (TS) is a common chronic neuropsychiatric disorder with a prevalence of approximately 1% in children and adolescents. TS is characterized by sudden involuntary motor tics along with vocal tics. A pathological study on postmortem patients has reported a 50-60% reduction in striatal gamma-aminobutyric acidergic (GABAergic) interneurons, suggesting a role for GABAergic system imbalances in tic disorder development. However, the effect of exogenous GABA administration on tic alleviation remains unreported.

Objective

In this study, we aim to investigate the therapeutic effects of exogenous GABA on TS-like behaviors in Sprague-Dawley rats and explore its potential mechanisms, including gut microbiota regulation, oxidative stress mitigation, and restoration of GABA-glutamate balance, to provide insights into TS pathogenesis and alternative treatment strategies.

Materials and Methods

A TS model rat was established through intraperitoneal administration of 3,3-Iminodipropionitrile (150 mg/kg/day), followed by GABA (20 mg/kg/day) administration by gavage. 15 minutes of behavioral testing (stereotypical behavior and head twitching behavior) was then conducted. 16S rRNA sequencing identified microbiome changes, and LC-MS assessed striatal metabolite changes.

Results

The results showed that a 4-week GABA treatment alleviated TS-like behavior in rats. GABA treatment led to an increase in Acinetobacter and other beneficial bacteria. GABA also significantly upregulated 15 striatal metabolites compared with TS group. By correlation analysis of striatal metabolites and intestinal bacteria, statistical analysis showed that Clostridium_sensu_stricto_1 was negatively correlated with metabolites on the top 20 differential gut microbiota and metabolites. Moreover, changes in gut microbiota correlated with alterations in striatal metabolites, suggesting a gut-brain axis involvement.

Conclusion

Exogenous GABA alleviated TS-like behavior in rats by reducing harmful gut flora and modulating striatal GABA-glutamate metabolism. Despite challenges like low blood-brain barrier permeability and dose safety in humans, GABA's therapeutic potential may be realized through prodrug development and optimized dosing. These findings are preliminary and require further clinical validation.

Computer reconstruction of gene networks controlling anxiety levels in humans and laboratory mice

Anxiety is a normotypic human condition, and like any other emotion has an adaptive value. But excessively high or low anxiety has negative consequences for adaptation, which primarily determines the importance of studying these two extreme conditions. At the same time, it is known that the perception of aversive stimuli associated with anxiety leads to changes in the activity of the brain's cingulate cortex. The advantage of animals as models in studying the genetic bases of anxiety in humans is in the ability to subtly control the external conditions of formation of a certain state, the availability of brain tissues, and the ability to create and study transgenic models, including through the use of differentially expressed genes of small laboratory animals from the family Muridae with low and high anxiety. Within the framework of the translational approach, a three-domain potential gene network, which is associated with generalized anxiety in humans, was reconstructed using mouse models with different levels of anxiety by automatically analyzing the texts of scientific articles. One domain is associated with reduced anxiety in humans, the second with increased anxiety, and the third is a dispatcher who activates one of the two domains depending on the status of the organism (genetic, epigenetic, physiological). Stages of work: (I) A list of genes expressed in the cingulate cortex of the wild type CD-1 mouse line from the NCBI GEO database (experiment GSE29014). Using the tools of this database, differences in gene expression levels were revealed in groups of mice with low and high (relatively normal) anxiety. (II) Search for orthologs of DEG in humans and mice associated with anxiety in the OMA Orthology database. (III) Computer reconstruction using the ANDSystem cognitive system based on (a) human orthologous genes from stage (III), (b) human genes from the MalaCards database associated with human anxiety. The proven methods of the translational approach for the reconstruction of gene networks for behavior regulation can be used to identify molecular genetic markers of human personality traits, propensity to psychopathology.

Anxiolytic Efficacy of Indirubin: In Vivo Approach Along with Receptor Binding Profiling and Molecular Interaction with GABAergic Pathways

Anxiety is a natural response to stress, characterized by feelings of worry, fear, or unease. The current research was conducted to investigate the anxiolytic effect of indirubin (IND) in different behavioral paradigms in Swiss albino mice. To observe the animal's behavioural response to assess anxiolytic activity, different tests were performed, such as the open-field (square cross, grooming, and rearing), swing, dark-light, and hole cross tests. The experimental mice were administered IND (5 and 10 mg/kg, p.o.), where diazepam (DZP) and vehicle were used as positive and negative controls, respectively. In addition, a combination treatment (DZP+IND-10) was provided to the animals to determine the modulatory effect of IND on DZP. Molecular docking approach was also conducted to determine the binding energy of IND with the GABAA receptor (α2 and α3 subunits) and pharmacokinetics were also estimated. The findings revealed that IND dose-dependently significantly (p<0.05) reduced the animal's movement exerting calming behavior like DZP. IND also demonstrated the highest docking score (-7.7 kcal/mol) against the α3 subunit, while DZP showed a lower docking value (-6.4 kcal/mol) than IND. The ADMET analysis revealed that IND has proper drug-likeness and pharmacokinetic characteristics. In conclusion, IND exerted anxiolytic effects through GABAergic Pathways.

An insight for the inhibition of anxiolytic and anti-convulsant effects in zebrafish using the curcumins via exploring molecular docking and molecular dynamics simulations

In the contemporary landscape, anxiety and seizures stand as major areas of concern, prompting researchers to explore potential drugs against them. While numerous drugs have shown the potential to treat these two neurological conditions, certain adverse effects emphasize the need for development of safer alternatives. This study seeks to employ an in silico approach to evaluate natural compounds, particularly curcumins, as potential inhibitors of GABA-AT to mitigate anxiety and seizures. The proposed methodology includes generating a compound library, minimizing energy, conducting molecular docking using AutoDock, molecular dynamics simulations using Amber, and MM-GBSA calculations. Remarkably, CMPD50 and CMPD88 exhibited promising binding affinities of - 9.0 kcal/mol and - 9.1 kcal/mol with chains A and C of GABA-AT, respectively. Further, MM-GBSA calculations revealed binding free energies of - 10.88 kcal/mol and - 10.72 kcal/mol in CMPD50 and CMPD88, respectively. ADME analysis showed that these compounds contain drug-likeness properties and might be considered as potential drug candidates. The findings from this study will have practical applications in the field of drug discovery for the development of safer and effective drugs for treatment of anxiety and seizures. Overall, this study will lay the groundwork for providing valuable insights into the potential therapeutic effects of curcumins in alleviating anxiety and seizures, establishing a computational framework for future experimental validation.

Anxiety disorders and the gut microbiota: a bibliometric and visual analysis

Introduction

Anxiety disorder is a common mental illness, yet its specific mechanisms remain unclear. Recent research has revealed a connection between gut microbiota and anxiety disorders. This study aims to assess the current global research landscape, highlight current topics of interest, and explore future research directions in the field of anxiety disorders and gut microbiota.

Methods

We extracted research review articles related to anxiety and gut microbiota from the Web of Science, covering the period from 2004 to 2023. We used VOSviewer 1.6.18.0, Scimago Graphica, and CiteSpace 6.2. R2 to visualize the contributions of countries, institutions, journals, authors, citations, and keywords in this field.

Result

A total of 1198 articles were included in this bibliometric analysis. Over the past two decades, both publications and citations have shown a steady increase. China, the United States, and Canada were the top three countries in terms of publication output. John Cryan from University College Cork had the highest number of publications and citation impact in this area of research. The journal Nutrients had the highest number of publications, while Brain Behavior and Immunity had the most citations. Key research themes in recent years have included anxiety, gut microbiota, depression, stress, gut-brain axis, and probiotics, all of which are likely to be important future research directions.

Conclusion

This analysis has key research areas and emerging trends, including risk factors, stressors, inflammatory responses, the gut-brain axis, and probiotics. These insights can guide researchers towards a more comprehensive understanding of recent advancements in this field, help shape future research directions and facilitate the identification of new therapeutic targets for anxiety disorder, ultimately improving clinical outcomes.

The Medial Prefrontal Cortex-Basolateral Amygdala Circuit Mediates Anxiety in Shank3 InsG3680 Knock-in Mice

Anxiety disorder is a major symptom of autism spectrum disorder (ASD) with a comorbidity rate of ~40%. However, the neural mechanisms of the emergence of anxiety in ASD remain unclear. In our study, we found that hyperactivity of basolateral amygdala (BLA) pyramidal neurons (PNs) in Shank3 InsG3680 knock-in (InsG3680+/+) mice is involved in the development of anxiety. Electrophysiological results also showed increased excitatory input and decreased inhibitory input in BLA PNs. Chemogenetic inhibition of the excitability of PNs in the BLA rescued the anxiety phenotype of InsG3680+/+ mice. Further study found that the diminished control of the BLA by medial prefrontal cortex (mPFC) and optogenetic activation of the mPFC-BLA pathway also had a rescue effect, which increased the feedforward inhibition of the BLA. Taken together, our results suggest that hyperactivity of the BLA and alteration of the mPFC-BLA circuitry are involved in anxiety in InsG3680+/+ mice.

Catatonia-asossicated urinary retention in geriatric patients: a case series report

BACKGROUND

Catatonia is an underdiagnosed neuropsychiatric condition, with only a few studies focusing on medical sequalae among elderly populations. Delayed treatment results in complications with high morbidity and mortality. Among elderly individuals, one such complication is urinary retention. Urinary retention can result in prolonged catheter use. In geriatric populations, prolonged use of catheters become particularly concerning and problematic as it can limit patient mobility, are potential sources for infection, and increase the risk for delirium. Catheter use has been independently associated with increased mortality in nursing home settings. Given the above risks and implications of catheter use, this case series describes clinical cases of catatonia-associated urinary retention specifically in older populations, whereby the use of electroconvulsive therapy (ECT) resulted in resolution of urinary retention concurrent with resolution of depressive and catatonic symptoms using validated scales.

CASE PRESENTATION

This study involved four patients ranging from 66-84 years old who met criteria for major depressive disorder and catatonia. At admission, Montgomery-Asberg Depression Rating Scale (MADRS) scores ranged from 40-56, indicating severe illness in all patients. All patients also met criteria for catatonia as measured by the Bush Francis Catatonia Rating Scale (BFCRS). During the admission, each patient experienced urinary retention as evidenced by post-void residual (PVR) bladder volumes ranging from 569-1400 mL. Medical workup was completed to exclude alternative causes for urinary retention. Each patient completed ECT treatment, ranging from 14-19 sessions which resulted in resolution of catatonia. All four patients were also noted to have PVR volumes ranging from 6-75 mL, thereby suggesting concurrent resolution of urinary retention. Posttreatment, the MADRS scores ranged from 3-16, indicating a mild or subthreshold index of illness. There was no recurrence of elevated post-void residual volumes, and therefore, all patients were discharged from hospital without the requirements of urinary catheter insertion.

CONCLUSIONS

To our knowledge, there are no case reports that describe the concurrent resolution of catatonia, depressive symptoms and urinary retention simultaneously using validated scales throughout the ECT treatment course. Furthermore, there are no prior reports describing catatonia-related urinary retention specifically among a group of geriatric populations. Identifying and treating catatonia in a timely manner can reduce the complications associated with prolonged catheter use. There remains a gap in current research to describe if there exists any overlapping mechanisms and pathways to explain how ECT can treat catatonia, depression, and catatonia-associated urinary retention.

Unlocking the Potential of Oxymatrine: A Comprehensive Review of Its Neuroprotective Mechanisms and Therapeutic Prospects in Neurological Disorders

Sophora flavescens, the source of oxymatrine, is gaining popularity due to its potential in neuroprotection and treatment of various neurological conditions like epilepsy, depression, Parkinson's, Alzheimer's and multiple sclerosis. Its natural occurrence and promising preliminary research highlight its ability to reduce nerve cell damage and inflammation, attributed to its antiapoptotic, antioxidant and anti-inflammatory properties. However, challenges like solubility, potential adverse effects and limited bioavailability hinder its full therapeutic utilization. Current strategies, including formulation optimization and innovative drug delivery systems, aim to enhance its efficacy and safety. Despite its potential, further research is necessary to overcome these obstacles and maximize its clinical effectiveness. Conclusively, oxymatrine demonstrates distinct neuroprotective properties, offering unique advantages over other agents currently being studied or used in clinical practice for neurological disorders. nevertheless, additional study is necessary to surmount current obstacles and maximize its effectiveness for clinical settings. This study provides a comprehensive overview of oxymatrine's neuroprotective mechanisms and therapeutic potential while emphasizing the need for continued investigation and development for practical clinical application.

Social stimuli impact behavioral responses to caffeine in the zebrafish

Caffeine is a widely consumed stimulant with dose-dependent effects on behavior. Across species, lower doses tend be anxiolytic and increase activity, while higher doses tend to be anxiogenic and decrease activity. Given the importance of the social environment on stress responses, we investigated how social stimuli modulate behavioral responses to caffeine. We exposed adult zebrafish to low (25 mg/L) or moderate (60 mg/L) caffeine either in isolation or within view of a stimulus group. Zebrafish are highly social, and social stimuli are known to buffer responses to environmental stressors. As predicted, we found that isolated fish were more sensitive to caffeine's anxiogenic effects and less sensitive to caffeine's stimulant effects. Among socially-exposed individuals, caffeine decreased social approach. Our data illustrate the importance of social context. Understanding how social cues shape pharmacological responses is important for understanding the external validity of studies that investigate drug effects in social species.

Chronic Nasal Administration of Kisspeptin-54 Regulates Mood-Related Disorders Via Amygdaloid GABA in Hemi-Parkinsonian Rats

Background

Depression and anxiety, the most prevalent neuropsychiatric manifestations in Parkinson’s disease (PD), negatively impact their quality of life.

Aims

To determine whether the chronic nasal administration of kisspeptin-54 (KP-54) could. Alleviate symptoms of anxiety and depression in hemi-Parkinsonian rats.

Study Design

Experimental study.

Methods

This study included adult Sprague Dawley male rats who were administered either a vehicle (artificial cerebrospinal fluid) or 6-hydroxydopamine (6-OHDA) unilaterally into the medial forebrain bundle. The vehicle, or KP-54 (3 nmol/kg, applied topically to the rhinarium), was administered daily for a seven-day period. The sucrose preference test (SPT), elevated plus maze test (EPMT), and open field test (OFT) were implemented to evaluate depression- and anxiety-like behaviors, respectively, seven days following the lesion surgery. Gamma-aminobutyric acid (GABA) concentrations in the amygdala were quantified using mass spectrometry. Tyrosine hydroxylase in substantia nigra was analyzed using immunohistochemistry.

Results

The nasal delivery of KP-54 significantly reduced depressionand anxiety-like behaviors that were induced by 6-OHDA, as indicated by the results of the SPT, OFT, and EPMT. Moreover, it was observed that nasal KP-54 effectively mitigated 6-OHDA-induced motor deficits and the loss of nigral dopaminergic neurons. The nasal administration of KP-54 augmented the decline in GABA levels in the amygdala induced by 6-OHDA. Furthermore, effective correlations were established between GABA concentrations and behavioral parameters.

Conclusion

The nasal delivery of KP-54 could function as a viable therapeutic alternative for treating mood-related disorders in PD.

Distinct acute stressors produce different intensity of anxiety-like behavior and differential glutamate release in zebrafish brain

Anxiety disorder is one of the most well-characterized behavioral disorders in individuals subjected to acute or chronic stress. However, few studies have demonstrated how different types of stressors can modulate the neurochemical alterations involved in the generation of anxiety. In this study, we hypothesize that subjects exposed to different aversive stimuli (mechanical, chemical, and spatial restriction) present varied intensities of anxiety-like responses associated with distinct patterns of gamma-aminobutyric acid (GABA) and glutamate release in the brain. Adult zebrafish, Danio rerio (n = 60), were randomly divided into four experimental groups; control, acute restraint stress (ARS), conspecific alarm substance (CAS), and chasing with net (CN). After the stress protocols, the animals were individually transferred to a novel tank diving test for behavioral analysis. Subsequently, their brains were collected and subjected to GABA and glutamate release assay for quantification by HPLC. Our behavioral results showed that all aversive stimuli were capable of inducing anxiety-like behavior. However, the impact of anxiogenic behavior was more prominent in the CN and CAS groups when compared to ARS. This phenomenon was evident in all analyzed behavioral parameters (time on top, freezing, mean speed, maximum speed, and erratic swimming). Our data also showed that all aversive stimuli significantly decreased GABA release compared to the control group. Only animals exposed to CN and CAS presented an increase in extracellular glutamate levels. Different acute stressors induced different levels of anxiety-like behavior in zebrafish as well as specific alterations in GABAergic and glutamatergic release in the brain. These results demonstrate the complexity of anxiety disorders, highlighting that both behavioral and neurochemical responses are highly context-dependent.

Ubiquitous extremely low frequency electromagnetic fields induces anxiety-like behavior: mechanistic perspectives

Anxiety is an adaptive condition characterized by heightened uneasiness, which in the long term can cause complications such as reducing the quality of life and problems related to the mental and physical health. Concerns have been raised regarding the potential dangers of extremely low frequency electromagnetic fields (ELF-EMF) ranging from 3 to 3000 Hz, which are omnipresent in our daily lives and there have been studies about the anxiogenic effects of these fields. Studies conducted in this specific area has revealed that ELF-EMF can have an impact on various brain regions, such as the hippocampus. In conclusion, studies have shown that ELF-EMF can interfere with hippocampus-prefrontal cortex pathway, inducing anxiety behavior. Also, ELF-EMF may initiate anxiety behavior by generating oxidative stress in hypothalamus and hippocampus. Moreover, ELF-EMF may induce anxiety behavior by reducing hippocampus neuroplasticity and increasing the NMDA2A receptor expression in the hippocampus. Furthermore, supplementation with antioxidants could serve as an effective protective measure against the adverse effects of FLF-FMF in relation to anxiety behavior.

Assessment of sedative activity of fraxin: In vivo approach along with receptor binding affinity and molecular interaction with GABAergic system

Insomnia is a sleep disorder in which you have trouble falling and/or staying asleep. This research aims to evaluate the sedative effects of fraxin (FX) on sleeping mice induced by thiopental sodium (TS). In addition, a molecular docking study was conducted to investigate the molecular processes underlying these effects. The study used adult male Swiss albino mice and administered FX (10 and 20 mg/kg, i.p.) and diazepam (DZP) (2 mg/kg) either separately or in combination within the different groups to examine their modulatory effects. After a period of 30 min, the mice that had been treated were administered (TS: 20 mg/kg, i.p.) to induce sleep. The onset of sleep for the mice and the length of their sleep were manually recorded. Additionally, a computational analysis was conducted to predict the role of gamma-aminobutyric acid (GABA) receptors in the sleep process and evaluate their pharmacokinetics and toxicity. The outcomes indicated that FX extended the length of sleep and reduced the time it took to fall asleep. When the combined treatment of FX and DZP showed synergistic sedative action. Also, FX had a binding affinity of -7.2 kcal/mol, while DZP showed -8.4 kcal/mol. The pharmacokinetic investigation of FX demonstrated favorable drug-likeness and strong pharmacokinetic characteristics. Ultimately, FX demonstrated a strong sedative impact in the mouse model, likely via interacting with the GABAA receptor pathways.

The benefits of ashwagandha (Withania somnifera) supplements on brain function and sports performance

Ashwagandha or Withania somnifera is an herbal plant belonging to the Solanaceae family. Because of its wide range of phytochemicals, ashwagandha root extract has been used in numerous research studies, either alone or in conjunction with other natural plants, for various biomedical applications, which include its anti-microbial, anti-inflammatory, anti-stress, anti-tumor, cardioprotective, and neuroprotective properties. Additionally, it improves endothelial function, lowers reactive oxygen species, controls apoptosis, and improves mitochondrial function. These properties make it a useful treatment for a variety of conditions, including age-related symptoms, anxiety, neurodegenerative diseases, diabetes, stress, arthritis, fatigue, and cognitive/memory impairment. Despite the numerous benefits of ashwagandha supplementation, there have been just four meta-analyses on the herb's effectiveness in treating anxiety, neurobehavioral disorders, impotence, and infertility. Moreover, no reviews exist that examine how ashwagandha affects antioxidant response and physical sports performance. Consequently, the goal of this study was to analyze the scientific literature regarding the effects of ashwagandha consumption on antioxidant response and athletic performance.

Exploring the sedative properties of natural molecules from hop cones (Humulus lupulus) as promising natural anxiolytics through GABA receptors and the human serotonin transporter

This research work aimed to identify the main components that are responsible for the sedative properties of hop cones and allocate their targets. This investigation was performed through molecular docking, molecular dynamic simulations, root mean square fluctuation (RMSF) analysis, and DFT calculation techniques. The tested compounds from Humulus lupulus were compared to diazepam and paroxetine. Molecular docking showed that two-thirds of the compounds had a good affinity to gamma-aminobutyric acid (GABA), outperforming diazepam, while only three surpassed paroxetine on the SERT. Compounds 3,5-dihydroxy-4,6,6-tris(3-methylbut-2-en-1-yl)-2-(3-methylbutanoyl)cyclohexa-2,4-dien-1-one (5) and (S,E)-8-(3,7-dimethylocta-2,6-dien-1-yl)-5,7-dihydroxy-2-(4-hydroxyphenyl)chromen-4-one (15) showed stable binding and favorable energy parameters, indicating their potential for targeting GABA receptors and the SERT. This study provides a basis for future clinical research on these promising compounds.

The role of psychotic-like experiences in the association between aberrant salience and anxiety: A psychopathological proposal based on a case-control study

AIM

Aberrant salience (AS) and psychotic-like experiences (PLEs) have been proven to be linked. Moreover, anxiety is a key symptom in psychosis-prone subjects and most psychotic patients. We propose a model that attempts to interpret the role of PLEs in the association between AS and anxiety among healthy controls and psychotic patients.

METHODS

Demographic and psychometric data (Aberrant Salience Inventory, Community Assessment of Psychic Experiences, Symptom Check List-90-revised) from 163 controls and 44 psychotic patients was collected. Descriptive statistics, correlations, a linear regression model and a mediation analysis with covariates were subsequently performed.

RESULTS

AS correlated with more frequent positive PLEs and higher anxiety levels in both patients and controls. However, positive PLEs' frequency mediated the relationship between AS and anxiety only among controls.

CONCLUSIONS

PLEs linked to AS appear to induce anxiety among the control group but not among psychotic patients. The progressive loss of both novelty and insight, which may, respectively, impair the somatic emotional reactivity to PLEs and the ability to recognize some bodily phenomena as the embodied correlates of anxiety, is seen as the most probable theoretical explanation.

Synthesis of versatile neuromodulatory molecules by a gut microbial glutamate decarboxylase

Dysbiosis of the microbiome correlates with many neurological disorders, yet very little is known about the chemistry that controls the production of neuromodulatory molecules by gut microbes. Here, we found that an enzyme glutamate decarboxylase (BfGAD) of a gut microbe Bacteroides fragilis forms multiple neuromodulatory molecules such as γ-aminobutyric acid (GABA), hypotaurine, taurine, homotaurine, and β-alanine. We evolved BfGAD and doubled its taurine productivity. Additionally, we increased its specificity towards the substrate L-glutamate. Here, we provide a chemical strategy via which the BfGAD activity could be fine-tuned. In future, this strategy could be used to modulate the production of neuromodulatory molecules by gut microbes.

Different dosage regimens of zuranolone in the treatment of major depressive disorder: A meta-analysis of randomized controlled trials

OBJECTIVE

To investigate the efficacy and safety of different dosage regimens of zuranolone in the treatment of patients with major depressive disorder (MDD).

METHODS

PubMed, Embase, The Cochrane Library and other databases were searched from inception until July 2019. Randomized controlled trials (RCTs) related to the efficacy and safety of zuranolone in the treatment of MDD were included. The data were extracted independently by 2 investigators and assessed the study quality by the Cochrane risk-of-bias tool. The primary outcome includes the 17-item HAMILTON total score (HAMD-17) and the incidence of adverse events (AEs).

RESULTS

Six high-quality RCTs with 1593 patients were finally included in our analysis. Zuranolone group achieve a notable treatment effect at day15 in HAMD-17 compared with placebo group (MD = -2.69, 95 % CI: -4.45 to -0.94, P < 0.05). For safety, no significant differences existed in the proportion of patients with AEs between zuranolone with placebo (RR = 1.25, 95 % CI: 0.99 to 1.58, P = 0.06).

CONCLUSION

Zuranolone has a significant efficacy in improving depressive symptoms in the short term and is positively correlated with the dosage administered. However, the efficacy of zuranolone decreased significantly when the time of administration was extended. Zuranolone demonstrated a controllable safety issue. But adverse effects increased as the dose of zuranolone was gradually increased to 50 mg.

Zuranolone for treatment of major depressive disorder: a systematic review and meta-analysis

Background

Current treatment modalities for Major Depressive Disorder have variable efficacies and a variety of side effects. To amend this, many trials for short term, well tolerated monotherapies are underway. One such option is Zuranolone (SAGE-217), which is a recent FDA approved antidepressant for Post Partum depression (PPD) and is undergoing clinical trials for PPD, major depressive disorder (MDD) and essential tremors (ET).

Objectives

Pool currently available data that compare Zuranolone to Placebo for the treatment of Major Depressive Disorder and evaluate its efficacy and safety profile.

Methods

We retrieved data from PUBMED and SCOPUS from inception to July 2023. We included articles comparing Zuranolone or SAGE 217 with placebo in patients suffering from Major Depressive Disorder. Review Manager 5.4 was used to analyze the outcomes including changes in the Hamilton Depression Rating Scale (HAM-D), Hamilton Anxiety Rating Scale (HAM-A) and Montgomery-Åsberg Depression Rating Scale (MADRS) scores from baseline as well as any treatment emergent adverse events (TEAEs) and severe adverse events.

Results

Our review analyzed 4 trials and the data of 1,357 patients. Patients treated with Zuranolone indicated a statistically significant effect in the change from baseline in HAM-D score (p = 0.0009; MD [95% CI]: -2.03 [-3.23, -0.84]) as well as in MADRS score (p = 0.02; MD [95% CI]: -2.30[-4.31, -0.30]) and HAM-A score (p = 0.03; MD [95% CI]: -1.41[-2.70, -0.11]) on 15th day when compared to the Placebo group. Zuranolone was also significantly associated with a higher response rate (p = 0.0008; OR [95% CI]: 1.63[1.14, 2.35]) and higher remission rate (p = 0.03; OR [95% CI]: 1.65[1.05, 2.59]) when compared with the placebo. As for safety, Zuranolone was significantly associated with 1 or more TEAE (p = 0.006; RR [95% CI]: 1.14[1.04, 1.24]) but an insignificant association with side effects that lead to drug discontinuation (p = 0.70; RR [95% CI]: 1.18[0.51, 2.76]) and serious adverse events (p = 0.48; RR [95% CI]: 1.46 [0.52, 4.10]) when compared with placebo.

Conclusion

Zuranolone is an effective and safe drug for short course major depressive disorder monotherapy. It shows results in 14 days (compared to 2-4 weeks that SSRI's take) and has anti-anxiolytic effects as well. However, only 4 trials have been used for the analysis and the sample size was small. The trials reviewed also cannot determine the long-term effects of the drug. More trials are needed to determine long term effects.

Novel LC-MS/MS Method for Simultaneous Determination of Monoamine Neurotransmitters and Metabolites in Human Samples

For the simultaneous determination of monoamine neurotransmitters (NTs) like dopamine, serotonin, noradrenaline, and epinephrine, and their metabolites (metanephrine, normetanephrine, 3-methoxytyramine, vanillylmandelic acid, 3,4-dihydroxyphenylacetic acid, homovanillic acid, and 5-hydroxyindoleacetic acid), a robust liquid chromatography method coupled with tandem mass spectrometry (LC-MS/MS) was introduced as the analytical method. This analytical method proved to be accurate for the simultaneous measurement of the amounts of 11 NTs and their metabolites in biological samples. The method proved to be more efficient and better than the previously reported method in terms of precision, recovery, sample requirement, and extraction procedure. The reported method requires only 100 μL of blood and 200 μL of urine, and the extraction procedure requires acetonitrile precipitation, filtration, drying, and reconstitution in water. The separation of all analytes was performed on an C18 column (4.6 mm × 150 mm and 1.8 μm). A 10 min gradient elution program with a mobile phase consisting of phase A (0.2% formic acid in water) and phase B (methanol) was used. The positive ionization mode was used for the detection of all analytes in multiple reaction monitoring (MRM). The proposed method was validated with an internal standard and yielded lower limits of detection and quantification ranges of 0.0182-0.0797 ng/mL and 0.0553-0.2415 ng/mL, respectively, with a good linearity (R2) between 0.9959 and 0.9994. The recoveries ranged from 73.37% to 116.63% in blood and from 80.9% to 115.33% in urine. For the NTs and metabolites, the intra- and interday % CV were 0.24-9.36 and 0.85-9.67, respectively. The developed LC-MS/MS method was successfully used for the determination of trace amounts of endogenous compounds in human blood and urine samples.

The cancer-immune dialogue in the context of stress

Although there is little direct evidence supporting that stress affects cancer incidence, it does influence the evolution, dissemination and therapeutic outcomes of neoplasia, as shown in human epidemiological analyses and mouse models. The experience of and response to physiological and psychological stressors can trigger neurological and endocrine alterations, which subsequently influence malignant (stem) cells, stromal cells and immune cells in the tumour microenvironment, as well as systemic factors in the tumour macroenvironment. Importantly, stress-induced neuroendocrine changes that can regulate immune responses have been gradually uncovered. Numerous stress-associated immunomodulatory molecules (SAIMs) can reshape natural or therapy-induced antitumour responses by engaging their corresponding receptors on immune cells. Moreover, stress can cause systemic or local metabolic reprogramming and change the composition of the gastrointestinal microbiota which can indirectly modulate antitumour immunity. Here, we explore the complex circuitries that link stress to perturbations in the cancer-immune dialogue and their implications for therapeutic approaches to cancer.

Potential Mechanisms of Casein Hexapeptide YPVEPF on Stress-Induced Anxiety and Insomnia Mice and Its Molecular Effects and Key Active Structure

The hexapeptide YPVEPF with strong sleep-enhancing effects could be detected in rat brain after a single oral administration as we previously proved. In this study, the mechanism and molecular effects of YPVEPF in the targeted stress-induced anxiety mice were first investigated, and its key active structure was further explored. The results showed that YPVEPF could significantly prolong sleep duration and improve the anxiety indexes, including prolonging the time spent in the open arms and in the center. Meanwhile, YPVEPF showed strong sleep-enhancing effects by significantly increasing the level of the GABA/Glu ratio, 5-HT, and dopamine in brain and serum and regulating the anabolism of multiple targets, but the effects could be blocked by bicuculline and WAY100135. Moreover, the molecular simulation results showed that YPVEPF could stably bind to the vital GABAA and 5-HT1A receptors due to the vital structure of Tyr-Pro-Xaa-Xaa-Pro-, and the electrostatic and van der Waals energy played dominant roles in stabilizing the conformation. Therefore, YPVEPF displayed sleep-enhancing and anxiolytic effects by regulating the GABA-Glu metabolic pathway and serotoninergic system depending on distinctive self-folding structures with Tyr and two Pro repeats.

A new method for isolation and purification of fusion-competent inhibitory synaptic vesicles

Synaptic vesicles specific to inhibitory GABA-releasing neurons are critical for regulating neuronal excitability. To study the specific molecular composition, architecture, and function of inhibitory synaptic vesicles, we have developed a new method to isolate and purify GABA synaptic vesicles from mouse brains. GABA synaptic vesicles were immunoisolated from mouse brain tissue using an engineered fragment antigen-binding region (Fab) against the vesicular GABA transporter (vGAT) and purified. Western blot analysis confirmed that the GABA synaptic vesicles were specifically enriched for vGAT and largely depleted of contaminants from other synaptic vesicle types, such as vesicular glutamate transporter (vGLUT1), and other cellular organelles. This degree of purity was achieved despite the relatively low abundance of vGAT vesicles compared to the total synaptic vesicle pool in mammalian brains. Cryo-electron microscopy images of these isolated GABA synaptic vesicles revealed intact morphology with circular shape and protruding proteinaceous densities. The GABA synaptic vesicles are functional, as assessed by a hybrid (ex vivo/in vitro) vesicle fusion assay, and they undergo synchronized fusion with synthetic plasma membrane mimic vesicles in response to Ca2+-triggering, but, as a negative control, not to Mg2+-triggering. Our immunoisolation method could also be applied to other types of vesicles.

Embryonic ethanol exposure and optogenetic activation of hypocretin neurons stimulate similar behaviors early in life associated with later alcohol consumption

The initiation of alcohol use early in life is one of the strongest predictors of developing a future alcohol use disorder. Clinical studies have identified specific behaviors during early childhood that predict an increased risk for excess alcohol consumption later in life. These behaviors, including increased hyperactivity, anxiety, novelty-seeking, exploratory behavior, impulsivity, and alcohol-seeking, are similarly stimulated in children and adolescent offspring of mothers who drink alcohol during pregnancy. Here we tested larval zebrafish in addition to young pre-weanling rats and found this repertoire of early behaviors along with the overconsumption of alcohol during adolescence to be increased by embryonic ethanol exposure. With hypocretin/orexin (Hcrt) neurons known to be stimulated by ethanol and involved in mediating these alcohol-related behaviors, we tested their function in larval zebrafish and found optogenetic activation of Hcrt neurons to stimulate these same early alcohol-related behaviors and later alcohol intake, suggesting that these neurons have an important role in producing these behaviors. Together, these results show zebrafish to be an especially useful animal model for investigating the diverse neuronal systems mediating behavioral changes at young ages that are produced by embryonic ethanol exposure and predict an increased risk for developing alcohol use disorder.

Phenols and GABAA receptors: from structure and molecular mechanisms action to neuropsychiatric sequelae

γ-Aminobutyric acid type A receptors (GABAARs) are members of the pentameric ligand-gated ion channel (pLGIC) family, which are widespread throughout the invertebrate and vertebrate central nervous system. GABAARs are engaged in short-term changes of the neuronal concentrations of chloride (Cl-) and bicarbonate (HCO3 -) ions by their passive permeability through the ion channel pore. GABAARs are regulated by various structurally diverse phenolic substances ranging from simple phenols to complex polyphenols. The wide chemical and structural variability of phenols suggest similar and different binding sites on GABAARs, allowing them to manifest themselves as activators, inhibitors, or allosteric ligands of GABAAR function. Interest in phenols is associated with their great potential for GABAAR modulation, but also with their subsequent negative or positive role in neurological and psychiatric disorders. This review focuses on the GABAergic deficit hypotheses during neurological and psychiatric disorders induced by various phenols. We summarize the structure-activity relationship of general phenol groups concerning their differential roles in the manifestation of neuropsychiatric symptoms. We describe and analyze the role of GABAAR subunits in manifesting various neuropathologies and the molecular mechanisms underlying their modulation by phenols. Finally, we discuss how phenol drugs can modulate GABAAR activity via desensitization and resensitization. We also demonstrate a novel pharmacological approach to treat neuropsychiatric disorders via regulation of receptor phosphorylation/dephosphorylation.

Measuring anxiety disorder in bipolar disorder using EVestG: broad impact of medication groups

Objectives

Anxiety disorder is present in approximately half of all bipolar disorder (BD) patients. There are neurologic bases for the comorbidity of balance (vestibular) disorders and anxiety. Our objective is to use electrovestibulography (EVestG), which is predominantly a measure of vestibular neural activity to not only quantitatively detect and measure comorbid anxiety disorder but also to quantitatively measure the impacts of anti-depressant, anti-psychotic, and mood stabilizer medication groups on anxiety measures in BD patients.

Methods

In a population of 50 (24 with anxiety disorder) depressive phase BD patients, EVestG signals were measured. Participants were labeled depression-wise as anxious or non-anxious using standard questionnaires. Analyses were conducted on the whole dataset as well as on matched (age/gender/MADRS) and "modeled medication-free" subsets. Modulations of the low-frequency EVestG firing pattern data were measured.

Findings

For BD, the main anxious minus non-anxious difference was the presence of an increase in spectral power proximal to 8-9 Hz, which was best attenuated by mood stabilizers.

Novelty

This is the first study to use an oto-acoustic physiological measure to quantify anxiety disorder in BD wherein it appears to manifest as a peak proximal to 8-9 Hz which we hypothesize as likely linked to hippocampal theta.

Distinct mechanisms of allopregnanolone and diazepam underlie neuronal oscillations and differential antidepressant effect

The rapid relief of depressive symptoms is a major medical requirement for effective treatments for major depressive disorder (MDD). A decrease in neuroactive steroids contributes to the pathophysiological mechanisms associated with the neurological symptoms of MDD. Zuranolone (SAGE-217), a neuroactive steroid that acts as a positive allosteric modulator of synaptic and extrasynaptic δ-subunit-containing GABAA receptors, has shown rapid-onset, clinically effective antidepressant action in patients with MDD or postpartum depression (PPD). Benzodiazepines, on the other hand, act as positive allosteric modulators of synaptic GABAA receptors but are not approved for the treatment of patients with MDD. It remains unclear how differences in molecular mechanisms contribute to the alleviation of depressive symptoms and the regulation of associated neuronal activity. Focusing on the antidepressant-like effects and neuronal activity of the basolateral amygdala (BLA) and medial prefrontal cortex (mPFC), we conducted a head-to-head comparison study of the neuroactive steroid allopregnanolone and the benzodiazepine diazepam using a mouse social defeat stress (SDS) model. Allopregnanolone but not diazepam exhibited antidepressant-like effects in a social interaction test in SDS mice. This antidepressant-like effect of allopregnanolone was abolished in extrasynaptic GABAA receptor δ-subunit knockout mice (δko mice) subjected to the same SDS protocol. Regarding the neurophysiological mechanism associated with these antidepressant-like effects, allopregnanolone but not diazepam increased theta oscillation in the BLA of SDS mice. This increase did not occur in δko mice. Consistent with this, allopregnanolone potentiated tonic inhibition in BLA interneurons via δ-subunit-containing extrasynaptic GABAA receptors. Theta oscillation in the mPFC of SDS mice was also increased by allopregnanolone but not by diazepam. Finally, allopregnanolone but not diazepam increased frontal theta activity in electroencephalography recordings in naïve and SDS mice. Neuronal network alterations associated with MDD showed decreased frontal theta and beta activity in depressed SDS mice. These results demonstrated that, unlike benzodiazepines, neuroactive steroids increased theta oscillation in the BLA and mPFC through the activation of δ-subunit-containing GABAA receptors, and this change was associated with antidepressant-like effects in the SDS model. Our findings support the notion that the distinctive mechanism of neuroactive steroids may contribute to the rapid antidepressant effects in MDD.

Gut microbiota mediates anxiety-like behaviors induced by chronic infection of Toxoplasma gondii in mice

BACKGROUND

Chronic infection with the neurotropic parasite Toxoplasma gondii (T. gondii) can cause anxiety and gut microbiota dysbiosis in hosts. However, the potential role of gut microbiota in anxiety induced by the parasite remains unclear.

METHODS

C57BL/6J mice were infected with 10 cysts of T. gondii. Antibiotic depletion of gut microbiota and fecal microbiota transplantation experiments were utilized to investigate the causal relationship between gut microbiota and anxiety. Anxiety-like behaviors were examined by the elevated plus maze test and the open field test; blood, feces, colon and amygdala were collected to evaluate the profiles of serum endotoxin (Lipopolysaccharide, LPS) and serotonin (5-hydroxytryptamine, 5-HT), gut microbiota composition, metabolomics, global transcriptome and neuroinflammation in the amygdala. Furthermore, the effects of Diethyl butylmalonate (DBM, an inhibitor of mitochondrial succinate transporter, which causes the accumulation of endogenous succinate) on the disorders of the gut-brain axis were evaluated.

RESULTS

Here, we found that T. gondii chronic infection induced anxiety-like behaviors and disturbed the composition of the gut microbiota in mice. In the amygdala, T. gondii infection triggered the microglial activation and neuroinflammation. In the colon, T. gondii infection caused the intestinal dyshomeostasis including elevated colonic inflammation, enhanced bacterial endotoxin translocation to blood and compromised intestinal barrier. In the serum, T. gondii infection increased the LPS levels and decreased the 5-HT levels. Interestingly, antibiotics ablation of gut microbiota alleviated the anxiety-like behaviors induced by T. gondii infection. More importantly, transplantation of the fecal microbiota from T. gondii-infected mice resulted in anxiety and the transcriptomic alteration in the amygdala of the antibiotic-pretreated mice. Notably, the decreased abundance of succinate-producing bacteria and the decreased production of succinate were observed in the feces of the T. gondii-infected mice. Moreover, DBM administration ameliorated the anxiety and gut barrier impairment induced by T. gondii infection.

CONCLUSIONS

The present study uncovers a novel role of gut microbiota in mediating the anxiety-like behaviors induced by chronic T. gondii infection. Moreover, we show that DBM supplementation has a beneficial effect on anxiety. Overall, these findings provide new insights into the treatment of T. gondii-related mental disorders.

Perineuronal Nets Alterations Contribute to Stress-Induced Anxiety-Like Behavior

Anxiety disorder is one of the most common mental disorders worldwide, affecting nearly 30% of adults. However, its underlying molecular mechanisms are still unclear. Here we subjected mice to chronic restraint stress (CRS), a paradigm known to induce anxiety-like behavior in mice. CRS mice exhibited anxiety-like behavior and reduced synaptic transmission in the medial prefrontal cortex (mPFC). Notably, Wisteria Floribunda agglutinin (WFA) staining showed a reduction of perineuronal nets (PNNs) expression in the mPFC of CRS mice. And the mRNA and protein levels of aggrecan (ACAN), a core component of PNNs, were also reduced. Parallelly, enzymatic digestion of PNNs in the mPFC by injecting Chondroitinase ABC (chABC) resulted in anxiety-like behavior in mice. Fluoxetine (FXT) is a clinically prescribed antidepressant/anxiolytic drug. FXT treatment in CRS mice not only ameliorated their deficits in behavior and synaptic transmissions, but also prevented CRS-induced reduction of PNNs and ACAN expressions. This study demonstrates that proper PNNs level is critical to brain functions, and their decline may serve as a pathological mechanism of anxiety disorders.

Monoamine Oxidase: A Potential Link in Papez Circuit to Generalized Anxiety Disorders

Anxiety is a common mental illness that affects a large number of people around the world, and its treatment is often based on the use of pharmacological substances such as benzodiazepines, serotonin, and 5-hydroxytyrosine (MAO) neurotransmitters. MAO neurotransmitters levels are deciding factors in the biological effects. This review summarizes the current understanding of the MAO system and its role in the modulation of anxiety-related brain circuits and behavior. The MAO-A polymorphisms have been implicated in the susceptibility to generalized anxiety disorder (GAD) in several investigations. The 5-HT system is involved in a wide range of physiological and behavioral processes, involving anxiety, aggressiveness, stress reactions, and other elements of emotional intensity. Among these, 5-HT, NA, and DA are the traditional 5-HT neurons that govern a range of biological activities, including sleep, alertness, eating, thermoregulation, pains, emotion, and memory, as anticipated considering their broad projection distribution in distinct brain locations. The DNMTs (DNA methyltransferase) protein family, which increasingly leads a prominent role in epigenetics, is connected with lower transcriptional activity and activates DNA methylation. In this paper, we provide an overview of the current state of the art in the elucidation of the brain's complex functions in the regulation of anxiety.

Perampanel increases seizure threshold in pentylenetetrazole-kindled mice and improves behavioral dysfunctions by modifying mRNA expression levels of BDNF/TrkB and inflammatory markers

Perampanel (PER), a novel 3rd-generation antiseizure drug that modulates altered post-synaptic glutamatergic storming by selectively inhibiting AMPA receptors, is recently approved to treat intractable forms of seizures. However, to date, presumably consequences of long-term PER therapy on the comorbid deleterious psychiatric disturbances and its correlation with neuroinflammatory parameters are not fully investigated in chronic models of epilepsy. Therefore, we investigated the real-time effect of PER on brain electroencephalographic (EEG) activity, behavioral alterations, redox balance, and relative mRNA expression in pentylenetetrazole (PTZ) induced kindling. Male BALB/c mice were pretreated with PER (0.125, 0.25, and 0.5 mg/kg) for 3 weeks and challenged with 11 injections of PTZ at the sub-threshold dose of 40 mg/kg every other day. vEEG from implanted cortical electrodes was monitored to elucidate seizure propagation and behavioral manifestations. Recorded EEG signals exhibited that PER 0.5 mg/kg pretreatment exceptionally impeded the onset of sharp epileptic spike-wave discharges and associated motor symptoms. Additionally, qEEG analysis showed that PER prevented alterations in absolute mean spectral power and reduced RMS amplitude of epileptogenic spikes vs PTZ control. Furthermore, our outcomes illustrated that PER dose-dependently attenuated PTZ-evoked anxiety-like behavior, memory deficits, and depressive-like behavior that was validated by a series of behavioral experiments. Moreover PER, significantly reduced lipid peroxidation, AChE, and increased levels of SOD and total thiol in the mice brain via AMPAR antagonism. Post-PTZ kindling provoked overstimulation of BDNF/TrkB signaling and increased release of pro-inflammatory cytokines that were reversed by PER with suppression of iNOS in brain immune cells. In conclusion, our findings highlight that PER might play an auspicious preventive role in the proepileptic transformation of brain circuits via suppression of BDNF/TrkB signaling and reduced transcriptional levels of neuroinflammatory markers leading to improvised epilepsy-induced neurobehavioral and neurochemical effects.

Unraveling Compositional Study, Chemometric Analysis, and Cell-Based Antioxidant Potential of Selective High Nutraceutical Value Amaranth Cultivars Using a GC-MS and NMR-Based Metabolomics Approach

Amaranthus (family Amaranthaceae) is a potentially nutritious pseudocereal also known as a functional food owing to its high nutritional quality grains especially rich in essential amino acids. Emerging study, however, unambiguously indicates that apart from essential nutrients like protein, other phytochemicals present in amaranth seeds provide excellent health benefits. Squalene is one such phytonutrient found in Amaranthus seeds, which is also its largest vegetal source. In this research work, GC-MS and NMR spectroscopy-based metabolomics have been utilized for the compositional analysis of Amaranthus seeds coupled with a multivariate data set. Investigation of nonpolar and polar seed extracts of six different cultivars of amaranth identified 47 primary and secondary metabolites. One-way ANOVA showed significant quantitative metabolic variations in different cultivars of amaranth. Multivariate principal component analysis of both the GC-MS and NMR analyzed data broadly classified in two groups showed significant variations in the polar (lysine, arginine, GABA, and myoinositol) and nonpolar (squalene, tryptophan, and alkylated phenols, which are potential nutraceutical agents) metabolites. The squalene content estimated using HPLC varied significantly (1.61 to 4.72 mg g-1 seed dry weight) among six different cultivars. Positive correlations were found among the cellular antioxidant activity and squalene content. Cultivar AM-3 having the maximum squalene content showed the highest antioxidant activity evaluated on the cellular level over human embryonic kidney cells, clearly revealing potent intercellular reactive oxygen species scavenging capacity and strong membrane lipid peroxidation inhibition potential. Oxidative stress markers such as MDA, SOD, GSH, and CAT levels in cells further corroborated the research work. The study also indicated high concentrations of lysine (80.49 mg g-1 dry seeds) in AM-2, squalene (0.47% by weight) in AM-3, and 2,4-di-tert-butyl phenol (18.64% peak area) and myoinositol (79.07 mg g-1 dry seeds) in AM-5. This novel comparative metabolomic study successfully profiles the nutrient composition of amaranth cultivars and provides the opportunity for the development of nutraceuticals and natural antioxidants from this functional food.

Distinct ACC Neural Mechanisms Underlie Authentic and Transmitted Anxiety Induced by Maternal Separation in Mice

It is known that humans and rodents are capable of transmitting stress to their naive partners via social interaction. However, a comprehensive understanding of transmitted stress, which may differ from authentic stress, thus revealing unique neural mechanisms of social interaction resulting from transmitted stress and the associated anxiety, is missing. We used, in the present study, maternal separation (MS) as a stress model to investigate whether MS causes abnormal behavior in adolescence. A key concern in the analysis of stress transmission is whether the littermates of MS mice who only witness MS stress ("Partners") exhibit behavioral abnormalities similar to those of MS mice themselves. Of special interest is the establishment of the neural mechanisms underlying transmitted stress and authentic stress. The results show that Partners, similar to MS mice, exhibit anxiety-like behavior and hyperalgesia after witnessing littermates being subjected to early-life repetitive MS. Electrophysiological analysis revealed that mice subjected to MS demonstrate a reduction in both the excitatory and inhibitory synaptic activities of parvalbumin interneurons (PVINs) in the anterior cingulate cortex (ACC). However, Partners differed from MS mice in showing an increase in the number and excitability of GABAergic PVINs in the ACC and in the ability of chemogenetic PVIN inactivation to eliminate abnormal behavior. Furthermore, the social transfer of anxiety-like behavior required intact olfactory, but not visual, perception. This study suggests a functional involvement of ACC PVINs in mediating the distinct neural basis of transmitted anxiety.SIGNIFICANCE STATEMENT The anterior cingulate cortex (ACC) is a critical brain area in physical and social pain and contributes to the exhibition of abnormal behavior. ACC glutamatergic neurons have been shown to encode transmitted stress, but it remains unclear whether inhibitory ACC neurons also play a role. We evaluate, in this study, ACC neuronal, synaptic and network activities and uncover a critical role of parvalbumin interneurons (PVINs) in the expression of transmitted stress in adolescent mice who had witnessed MS of littermates in infancy. Furthermore, inactivation of ACC PVINs blocks transmitted stress. The results suggest that emotional contagion has a severe effect on brain function, and identify a potential target for the treatment of transmitted anxiety.

Anxiolytic effect of antidiabetic metformin is mediated by AMPK activation in mPFC inhibitory neurons

Diabetic patients receiving the antidiabetic drug metformin have been observed to exhibit a lower prevalence of anxiety disorders, yet the precise mechanism behind this phenomenon is unclear. In our study, we found that anxiety induces a region-specific reduction in AMPK activity in the medial prefrontal cortex (mPFC). Concurrently, transgenic mice with brain-specific AMPK knockout displayed abnormal anxiety-like behaviors. Treatment with metformin or the overexpression of AMPK restored normal AMPK activity in the mPFC and mitigated social stress-induced anxiety-like behaviors. Furthermore, the specific genetic deletion of AMPK in the mPFC not only instigated anxiety in mice but also nullified the anxiolytic effects of metformin. Brain slice recordings revealed that GABAergic excitation and the resulting inhibitory inputs to mPFC pyramidal neurons were selectively diminished in stressed mice. This reduction led to an excitation-inhibition imbalance, which was effectively reversed by metformin treatment or AMPK overexpression. Moreover, the genetic deletion of AMPK in the mPFC resulted in a similar defect in GABAergic inhibitory transmission and a consequent hypo-inhibition of mPFC pyramidal neurons. We also generated a mouse model with AMPK knockout specific to GABAergic neurons. The anxiety-like behaviors in this transgenic mouse demonstrated the unique role of AMPK in the GABAergic system in relation to anxiety. Therefore, our findings suggest that the activation of AMPK in mPFC inhibitory neurons underlies the anxiolytic effects of metformin, highlighting the potential of this primary antidiabetic drug as a therapeutic option for treating anxiety disorders.

Cryo-EM structure of GABA transporter 1 reveals substrate recognition and transport mechanism

The inhibitory neurotransmitter γ-aminobutyric acid (GABA) is cleared from the synaptic cleft by the sodium- and chloride-coupled GABA transporter GAT1. Inhibition of GAT1 prolongs the GABAergic signaling at the synapse and is a strategy to treat certain forms of epilepsy. In this study, we present the cryo-electron microscopy structure of Rattus norvegicus GABA transporter 1 (rGAT1) at a resolution of 3.1 Å. The structure elucidation was facilitated by epitope transfer of a fragment-antigen binding (Fab) interaction site from the Drosophila dopamine transporter (dDAT) to rGAT1. The structure reveals rGAT1 in a cytosol-facing conformation, with a linear density in the primary binding site that accommodates a molecule of GABA, a displaced ion density proximal to Na site 1 and a bound chloride ion. A unique insertion in TM10 aids the formation of a compact, closed extracellular gate. Besides yielding mechanistic insights into ion and substrate recognition, our study will enable the rational design of specific antiepileptics.

Datura metel stramonium exacerbates behavioral deficits, medial prefrontal cortex, and hippocampal neurotoxicity in mice via redox imbalance

BACKGROUND

Datura metel (DM) stramonium is a medicinal plant often abused by Nigerians due to its psychostimulatory properties. Hallucinations, confusion, agitation, aggressiveness, anxiety, and restlessness are reported amongst DM users. Earlier studies suggest that DM induces neurotoxicity and affect brain physiology. However, the exact neurological effects of DM extract in the medial prefrontal cortex (mPFC) and hippocampal morphology have not been elucidated. In this study, we evaluated the hypothesis that oral exposure to DM extract exerts a neurotoxic effect by increasing oxidative stress in the mPFC and the hippocampus and induces behavioral deficits in mice.

RESULTS

DM methanolic extract exposure significantly increased MDA and NO levels and reduced SOD, GSH, GPx and CAT activities in mice brains. In addition, our results showed that DM exposure produced cognitive deficits, anxiety, and depressive-like behaviour in mice following oral exposure for 28 days. Moreover, the mPFC and hippocampus showed neurodegenerative features, loss of dendritic and axonal arborization, a dose-dependent decrease in neuronal cell bodies' length, width, area, and perimeter, and a dose-dependent increase in the distance between neuronal cell bodies.

CONCLUSIONS

Oral exposure to DM in mice induces behavioural deficits, mPFC and hippocampal neuronal degenerations via redox imbalance in the brain of mice. These observations confirm the neurotoxicity of DM extracts and raises concerns on the safety and potential adverse effects of DM in humans.

Cocaine Exposure Increases Excitatory Synaptic Transmission and Intrinsic Excitability in the Basolateral Amygdala in Male and Female Rats and across the Estrous Cycle

INTRODUCTION

Sex and ovarian hormones influence cocaine seeking and relapse vulnerability, but less is known regarding the cellular and synaptic mechanisms contributing to these behavioral sex differences. One factor thought to influence cue-induced seeking behavior following withdrawal is cocaine-induced changes in the spontaneous activity of pyramidal neurons in the basolateral amygdala (BLA). However, the mechanisms underlying these changes, including potential sex or estrous cycle effects, are unknown.

METHODS

Ex vivo whole-cell patch clamp electrophysiology was conducted to investigate the effects of cocaine exposure, sex, and estrous cycle fluctuations on two properties that can influence spontaneous activity of BLA pyramidal neurons: (1) frequency and amplitude of spontaneous excitatory postsynaptic currents (sEPSCs) and (2) intrinsic excitability. Recordings of BLA pyramidal neurons were conducted in adult male and female rats and across the estrous cycle following 2-4 weeks of withdrawal from extended-access cocaine self-administration (6 h/day for 10 days) or drug-naïve conditions.

RESULTS

In both sexes, cocaine exposure increased the frequency, but not amplitude, of sEPSCs and neuronal intrinsic excitability. Across the estrous cycle, sEPSC frequency and intrinsic excitability were significantly elevated only in cocaine-exposed females in the estrus stage of the cycle, a stage when cocaine-seeking behavior is known to be enhanced.

CONCLUSIONS

Here, we identify potential mechanisms underlying cocaine-induced alterations in the spontaneous activity of BLA pyramidal neurons in both sexes along with changes in these properties across the estrous cycle.

Behavioral and neuroinflammatory changes caused by glyphosate: Base herbicide in mice offspring

BACKGROUND

Glyphosate is a pesticide considered of low toxicity, but scientific evidences show it can be harmful to health. This study aimed to evaluate the toxicity in mice offspring exposed to glyphosate-based herbicide (GBH) during the intrauterine period.

METHODS

Female matrices received glyphosate 0.3 mg/kg daily per oral throughout the gestational period, which was variable between 18 and 22 days. From the 25th until the 28th days post-birth, mice offspring were subjected to behavioral tests, and the prefrontal cortex was processed for immunohistochemical analysis.

RESULTS

Two significant behavioral changes were observed: anxiety in the GLIF0.3 group, increase in the behavior burying marbles in the marble-burying test and hyperactivity, expressed by the significant increase of the crossing number in the open field test. The increased microglia, TNF-alpha, and astrocyte expression were also observed in the prefrontal cortex of offspring treated with GLIF0.3.

CONCLUSION

Exposure to GBH during mice intrauterine development induces hyperactive and anxious behavior, evidencing neuroinflammation.

Function of the GABAergic System in Diabetic Encephalopathy

Diabetes is a common metabolic disease characterized by loss of blood sugar control and a high rate of complications. γ-Aminobutyric acid (GABA) functions as the primary inhibitory neurotransmitter in the adult mammalian brain. The normal function of the GABAergic system is affected in diabetes. Herein, we summarize the role of the GABAergic system in diabetic cognitive dysfunction, diabetic blood sugar control disorders, diabetes-induced peripheral neuropathy, diabetic central nervous system damage, maintaining diabetic brain energy homeostasis, helping central control of blood sugar and attenuating neuronal oxidative stress damage. We show the key regulatory role of the GABAergic system in multiple comorbidities in patients with diabetes and hope that further studies elucidating the role of the GABAergic system will yield benefits for the treatment and prevention of comorbidities in patients with diabetes.

Effects of fungal based bioactive compounds on human health: Review paper

Since the first years of history, microbial fermentation products such as bread, wine, yogurt and vinegar have always been noteworthy regarding their nutritional and health effects. Similarly, mushrooms have been a valuable food product in point of both nutrition and medicine due to their rich chemical components. Alternatively, filamentous fungi, which can be easier to produce, play an active role in the synthesis of some bioactive compounds, which are also important for health, as well as being rich in protein content. Therefore, this review presents some important bioactive compounds (bioactive peptides, chitin/chitosan, β-glucan, gamma-aminobutyric acid, L-carnitine, ergosterol and fructooligosaccharides) synthesized by fungal strains and their health benefits. In addition, potential probiotic- and prebiotic fungi were researched to determine their effects on gut microbiota. The current uses of fungal based bioactive compounds for cancer treatment were also discussed. The use of fungal strains in the food industry, especially to develop innovative food production, has been seen as promising microorganisms in obtaining healthy and nutritious food.

Agarwood essential oil inhalation exerts antianxiety and antidepressant effects via the regulation of Glu/GABA system homeostasis

Depression and anxiety are common diseases that endanger the physical and mental health of individuals. Agarwood incense inhalation has been used as a traditional Chinese medicine for relaxation and to improve sleep for centuries. In a previous study by the authors it was demonstrated that agarwood essential oil (AEO) injection exerted anxiolytic and antidepressant effects. Therefore the present study further investigated the anxiolytic and antidepressant effects of AEO inhalation on anxiolytic mice induced by M-chlorophenylpiperazine and depressive mice induced by chronic unpredictable mild stress. The results demonstrated that AEO exerted a significant anxiolytic effect, whereby autonomous movements were inhibited during the light dark exploration test and open field test. Furthermore, the tail suspension test and the forced swimming test demonstrated that AEO also exerted an antidepressant effect, whereby the immobility times were decreased. Moreover, AEO was determined to increase the levels of 5-hydroxytryptamine, γ-aminobutyric acid (GABA) A receptor (GABA_A) and glutamate (Glu) in anxiolytic mice and inhibit the levels of GABA_A and Glu in depressive mice. Further investigations into how AEO affected the Glu/GABA system demonstrated that AEO markedly increased the protein expression levels of GABA transaminase (GABAT), glutamate metabotropic receptor 5 (GRM5), glutamate ionotropic receptor AMPA type subunit 1 (GluR1) and vesicular glutamate transporter 1 (VGluT1). Furthermore, AEO reduced the expression levels of GABAT, glutamate ionotropic receptor NMDA type subunit 2B and GRM5, and enhanced the expression levels of GluR1 and VGluT1. These results demonstrated that AEO potentially possesses antianxiety and antidepressant properties. The present study determined that the mechanism was related to the regulation of Glu/GABA neurotransmitter system homeostasis.

Personality and Family Risk Factors for Poor Mental Well-Being

There is evidence that differentiation of self (DoS) contributes to the regulation of emotions at a young age, resulting in reduced anxiety and improved mental well-being. However, there is little evidence of the relationships between these four dimensions (DoS, self-regulation, anxiety, and mental well-being), or of the potential mediating role of self-regulation and anxiety. Our primary goal was therefore to consider the links between DoS, self-regulation, anxiety, and mental well-being. It was hypothesized that DoS (emotional reactivity, I-position, emotional cutoff, fusion with others) will be positively associated with mental well-being through the mediation of self-regulation (promotion-focused, prevention-focused) and anxiety. The study included 460 participants with a mean age of 41.18 (SD = 14.97, range = 19-60). Of them, 224 (48.7%) were women. Participants filled out four questionnaires: the Differentiation of Self Inventory-Revised, General Regulatory Focus Measure, the anxiety scale from DASS-21, and the Warwick-Edinburgh Mental Well-being Scale. The findings showed that emotional cutoff positively predicted prevention and anxiety, but did not predict promotion. In addition, promotion positively predicted mental well-being. Finally, promotion mediated the relationship between I-position and mental well-being. The results indicate that well-differentiated individuals function optimally and enjoy good quality of life.

Maternal separation in mice leads to anxiety-like/aggressive behavior and increases immunoreactivity for glutamic acid decarboxylase and parvalbumin in the adolescence ventral hippocampus

It has been reported that stressful events in early life influence behavior in adulthood and are associated with different psychiatric disorders, such as major depression, post-traumatic stress disorder, bipolar disorder, and anxiety disorder. Maternal separation (MS) is a representative animal model for reproducing childhood stress. It is used as an animal model for depression, and has well-known effects, such as increasing anxiety behavior and causing abnormalities in the hypothalamic-pituitary-adrenal (HPA) axis. This study investigated the effect of MS on anxiety or aggression-like behavior and the number of GABAergic neurons in the hippocampus. Mice were separated from their dams for four hours per day for 19 d from postnatal day two. Elevated plus maze (EPM) test, resident-intruder (RI) test, and counted glutamic acid decarboxylase 67 (GAD67) or parvalbumin (PV) positive cells in the hippocampus were executed using immunohistochemistry. The maternal segregation group exhibited increased anxiety and aggression in the EPM test and the RI test. GAD67-positive neurons were increased in the hippocampal regions we observed: dentate gyrus (DG), CA3, CA1, subiculum, presubiculum, and parasubiculum. PV-positive neurons were increased in the DG, CA3, presubiculum, and parasubiculum. Consistent with behavioral changes, corticosterone was increased in the MS group, suggesting that the behavioral changes induced by MS were expressed through the effect on the HPA axis. Altogether, MS alters anxiety and aggression levels, possibly through alteration of cytoarchitecture and output of the ventral hippocampus that induces the dysfunction of the HPA axis.

Ketogenic Diet and Inflammation: Implications for Mood and Anxiety Disorders

The ketogenic diet, known as a low-carbohydrate, high-protein, and high-fat diet, drastically restrains the major source of energy for the body, forcing it to burn all excess fat through a process called ketosis-the breaking down of fat into ketone bodies. First suggested as a medical treatment for children suffering from epilepsy, this diet has gained increased popularity as a rapid weight loss strategy. Over the past few years, there have been numerous studies suggesting that the ketogenic diet may provide therapeutic effects for several psychiatric conditions such as mood- and anxiety-related disorders. However, despite significant progress in research, the mechanisms underlying its therapeutic effects remain largely unexplored and are yet to be fully elucidated. This chapter provides an in-depth overview of preclinical and clinical evidence supporting the use of a ketogenic diet in the management of mood and anxiety disorders and discusses its relationship with inflammatory processes and potential mechanisms of actions for its therapeutic effects.

Effects of Current Psychotropic Drugs on Inflammation and Immune System

The immune system and inflammation are involved in the pathological progression of various psychiatric disorders such as depression or major depressive disorder (MDD), generalized anxiety disorder (GAD) or anxiety, schizophrenia, Alzheimer's disease (AD), and Huntington's disease. It is observed that levels of inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and other markers are highly increased in the abovementioned disorders. The inflammation and immune component also lead to enhance the oxidative stress. The oxidative stress and increased production of reactive oxygen species (ROS) are considered as important factors that are involved in pathological progression of psychiatric disorders. Increase production of ROS is associated with excessive inflammation followed by cell necrosis and death. The psychotropic drugs are mainly work through modulations of neurotransmitter system. However, it is evident that inflammation and immune modulation are also having important role in the progression of psychiatric disorders. Rationale of the use of current psychotropic drugs is modulation of immune system by them. However, the effects of psychotropic drugs on the immune system and how these might contribute to their efficacy remain largely unclear. The drugs may act through modification of inflammation and related markers. The main purpose of this book chapter is to address the role of current psychotropic drugs on inflammation and immune system. Moreover, it will also address the role of inflammation in the progression of psychiatric disorders.

Posterodorsal Medial Amygdala Urocortin-3, GABA, and Glutamate Mediate Suppression of LH Pulsatility in Female Mice

The posterodorsal subnucleus of the medial amygdala (MePD) is an upstream modulator of the hypothalamic-pituitary-gonadal (HPG) and hypothalamic-pituitary-adrenal (HPA) axes. Inhibition of MePD urocortin-3 (Ucn3) neurons prevents psychological stress-induced suppression of luteinizing hormone (LH) pulsatility while blocking the stress-induced elevations in corticosterone (CORT) secretion in female mice. We explore the neurotransmission and neural circuitry suppressing the gonadotropin-releasing hormone (GnRH) pulse generator by MePD Ucn3 neurons and we further investigate whether MePD Ucn3 efferent projections to the hypothalamic paraventricular nucleus (PVN) control CORT secretion and LH pulsatility. Ucn3-cre-tdTomato female ovariectomized (OVX) mice were unilaterally injected with adeno-associated virus (AAV)-channelrhodopsin 2 (ChR2) and implanted with optofluid cannulae targeting the MePD. We optically activated Ucn3 neurons in the MePD with blue light at 10 Hz and monitored the effect on LH pulses. Next, we combined optogenetic stimulation of MePD Ucn3 neurons with pharmacological antagonism of GABAA or GABAB receptors with bicuculline or CGP-35348, respectively, as well as a combination of NMDA and AMPA receptor antagonists, AP5 and CNQX, respectively, and observed the effect on pulsatile LH secretion. A separate group of Ucn3-cre-tdTomato OVX mice with 17β-estradiol replacement were unilaterally injected with AAV-ChR2 in the MePD and implanted with fiber-optic cannulae targeting the PVN. We optically stimulated the MePD Ucn3 efferent projections in the PVN with blue light at 20 Hz and monitored the effect on CORT secretion and LH pulses. We reveal for the first time that activation of Ucn3 neurons in the MePD inhibits GnRH pulse generator frequency via GABA and glutamate signaling within the MePD, while MePD Ucn3 projections to the PVN modulate the HPG and HPA axes.

Regulation of N-type calcium channels by nociceptin receptors and its possible role in neurological disorders

Activation of nociceptin opioid peptide receptors (NOP, a.k.a. opioid-like receptor-1, ORL-1) by the ligand nociceptin/orphanin FQ, leads to G protein-dependent regulation of Cav2.2 (N-type) voltage-gated calcium channels (VGCCs). This typically causes a reduction in calcium currents, triggering changes in presynaptic calcium levels and thus neurotransmission. Because of the widespread expression patterns of NOP and VGCCs across multiple brain regions, the dorsal horn of the spinal cord, and the dorsal root ganglia, this results in the alteration of numerous neurophysiological features. Here we review the regulation of N-type calcium channels by the NOP-nociceptin system in the context of neurological conditions such as anxiety, addiction, and pain.

Dietary supplements in neurological diseases and brain aging

A healthy diet shapes a healthy mind. Diet quality has a strong association with brain health. Diet influences the onset and consequences of neurological diseases, and dietary factors may influence mental health at individual and population level. The link between unhealthy diet, impaired cognitive function and neurodegenerative diseases indicates that adopting a healthy diet would ultimately afford prevention and management of neurological diseases and brain aging. Neurodegenerative diseases are of multifactorial origin and result in progressive loss of neuronal function in the brain, leading to cognitive impairment and motoneuron disorders. The so-called Mediterranean diet (MedDiet) with its healthy ingredients rich in antioxidant, anti-inflammatory, immune, neuroprotective, antidepressant, antistress and senolytic activity plays an essential role in the prevention and management of neurological diseases and inhibits cognitive decline in neurodegenerative diseases such as Alzheimer's, Parkinson's and Huntington's diseases. The MedDiet also modulates the gut-brain axis by promoting a diversity of gut microbiota. In view of the importance of diet in neurological diseases management, this review focuses on the dietary components, natural compounds and medicinal plants that have proven beneficial in neurological diseases and for brain health. Among them, polyphenols, omega-3 fatty acids, B vitamins and several ayurvedic herbs have promising beneficial effects.

Repeated social defeat stress exacerbates lipopolysaccharide-induced behavioural deficits in mice: ameliorative role of Chrysophyllum albidum fruit extract through anti-neuroinflammation, antioxidant and neurochemical balance

Development of neuropsychiatric disorder is associated with stress-related increase in pro-inflammatory cytokines. Chrysophyllum albidum fruit is an edible tropical fruit containing vitamins and phenolic compounds, well known for their anti-inflammatory and antioxidant activities. This study was designed to investigate the neuroprotective effect of C. albidum fruit extract (CAFE) on stress and lipopolysaccharide (LPS)-induced behavioral and neurochemical impairments in mice. Male Swiss mice were divided into 6 groups (n = 6). Groups 1-3 were orally treated daily for 14 days with normal saline (0.1 mL/10 g), CAFE (100 mg/kg) and Ferulic acid (FA, 10 mg/kg), and left in home cage as controls. Groups 4-6 were treated similarly but subjected to repeated social defeat (RSD) stress using the resident-intruder model from days 1-14. The RSD-animals were injected with LPS (125 µg/kg, i.p) 60 min after each RSD session from days 8-14. Neurobehavioral functions: locomotor, cognitive and anxiety-like behaviors were assessed 24 h after the last treatment. Pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α), dopamine, acetylcholinesterase, glutamic acid decarboxylase (GAD), malondialdehyde, nitrites, and reduced glutathione (GSH) were determined in brain tissue. CAFE significantly attenuated RSD and LPS-induced hypolocomotion, cognitive impairment and anxiety-like behavior when compared to the control. Treatment with CAFE also significantly reversed the negative effects of RSD and LPS on pro-inflammatory cytokines, dopamine, acetylcholinesterase, GAD, and oxidative-nitrosative stress levels. The findings clearly indicated that Chrysophyllum albidum fruit demonstrated neuroprotective effects and can play a key role in mitigating against chronic stress and inflammation linked to neuropsychiatric disorders.