Mechanism of action of benzodiazepines on GABAA receptors

Multimodal sleep signal tensor decomposition and hidden Markov Modeling for temazepam-induced anomalies across age groups

BACKGROUND

Recent advances in multimodal signal analysis enable the identification of subtle drug-induced anomalies in sleep that traditional methods often miss.

NEW METHOD

We develop and introduce the Dynamic Representation of Multimodal Activity and Markov States (DREAMS) framework, which embeds explainable artificial intelligence (XAI) techniques to model hidden state transitions during sleep using tensorized EEG, EMG, and EOG signals from 22 subjects across three age groups (18-29, 30-49, and 50-66 years). By combining Tucker decomposition with probabilistic Hidden Markov Modeling, we quantified age-specific, temazepam-induced hidden states and significant differences in transition probabilities.

RESULTS

Jensen-Shannon Divergence (JSD) was employed to assess variability in hidden state transitions, with older subjects (50-66 years) under temazepam displaying heightened transition variability and network instability as indicated by a 48.57 % increase in JSD (from 0.35 to 0.52) and reductions in network density by 12.5 % (from 0.48 to 0.42) and modularity by 21.88 % (from 0.32 to 0.25). These changes reflect temazepam's disruptive impact on sleep architecture in older adults, aligning with known age-related declines in sleep stability and pharmacological sensitivity. In contrast, younger subjects exhibited lower divergence and retained relatively stable, cyclical transition patterns. Anomaly scores further quantified deviations in state transitions, with older subjects showing increased transition uncertainty and marked deviations in REM-like to NREM state transitions.

COMPARISON WITH EXISTING METHODS

This XAI-driven framework provides transparent, age-specific insights into temazepam's impact on sleep dynamics, going beyond traditional methods by identifying subtle, pharmacologically induced changes in sleep stage transitions that would otherwise be missed.

CONCLUSIONS

DREAMS supports the development of personalized interventions based on sleep transition variability across age groups, offering a powerful tool to understand temazepam's age-dependent effects on sleep architecture.

Effects of levetiracetam an antiepileptic drug on the multi-biological parameters in African catfish Clarias gariepinus (Burchell, 1822)

This study investigated the impact of levetiracetam on the multi-biological parameters in juvenile Clarias gariepinus. Fish were exposed to 0.2, 0.6, and 0.8 mg/L of levetiracetam and filtered dechlorinated water (control) for 10 days, followed by a recovery period of 5 days. Blood samples were collected periodically for haematological and serum biochemical profiling, and the fish were sacrificed for the liver and brain tissues' analysis. Skin colouration, mucus secretion, and air-gulping increased with concentration and duration of exposure, while swimming rate and opercula movement decreased. A significant (p < 0.05) dose- and duration-dependent decrease was recorded in the red blood cells, packed cell volume, haemoglobin, and white blood cell counts, while the opposite was recorded in the mean corpuscular haemoglobin, volume, and haemoglobin concentrations. Compared to the control, there were no significant differences in the values of the differential leukocyte counts, except for lymphocytes, which were significantly (p < 0.05) lower in the highest concentration at the end of the exposure period. Aspartate and alanine aminotransferase and alkaline phosphatase activities increased significantly (p < 0.05), while the values for protein and glucose were reduced compared to the control. The oxidative stress biomarkers, liver catalase, superoxide dismutase, and glutathione peroxidase activities decreased significantly (p < 0.05), while malondialdehyde and acetylcholinesterase activities increased significantly (p < 0.05) compared to the control. The activities were duration- and concentration-dependent. No significant difference in the correction factor, while the hepatosomatic index decreased significantly (p < 0.05) compared to the control. The parameters returned to normal after post 5-day withdrawal of levetiracetam administration. The study indicated that levetiracetam is toxic to fish.

GABALAGEN Alleviates Stress-Induced Sleep Disorders in Rats

(1) Background: Gamma-aminobutyric acid (GABA) is an amino acid and the primary inhibitory neurotransmitter in the brain. GABA has been shown to reduce stress and promote sleep. GABALAGEN (GBL) is the product of fermented fish collagen by Lactobacillus brevis BJ20 and Lactobacillus plantarum BJ21, naturally enriched with GABA through the fermentation process and characterized by low molecular weight. (2) Methods: The present study evaluated the GABAA affinity of GBL through receptor binding assay. The sedative effects of GBL were investigated through electroencephalography (EEG) analysis in an animal model of electro foot shock (EFS) stress-induced sleep disorder, and then we examined the expression of orexin and the GABAA receptor in the brain region using immunohistochemistry and an enzyme-linked immunosorbent assay (ELISA). (3) Results: We found that on the binding assay, GBL displayed high affinity to the GABAA receptor. Also, after treatment with GBL, the percentage of the total time in rapid eye movement (REM) and non-rapid eye movement (NREM) sleep was significantly and dose-dependently increased in EFS-induced rats. Consistent with behavioral results, the GBL-treated groups showed that the expression of GABAA receptor immune-positive cells in the VLPO was markedly and dose-dependently increased. Also, the GBL-treated groups showed that the expression of the orexin-A level in LH was significantly decreased. (4) Conclusions: GBL showed efficacy and potential to be used as an anti-stress therapy to treat sleep deprivation through the stimulation of GABAA receptors and the consequent inhibition of orexin activity.

Anxiety-Like Behaviors in Mice Unmasked: Revealing Sex Differences in Anxiety Using a Novel Light-Heat Conflict Test

Anxiety and chronic pain afflict hundreds of millions worldwide. Anxiety and pain are more prevalent in females compared to males. Unfortunately, robust sex differences in human anxiety are not recapitulated in rodent tests, and results from rodent pain studies frequently fail to translate clinically. Therefore, there is a need to develop tests that reflect the differential salience of anxiety or pain-related stimuli between the sexes. Accordingly, here we introduce the Thermal Increments Dark-Light (TIDAL) conflict test. The TIDAL test places an anxiety-relevant stimulus (dark vs. illuminated chamber) in conflict with a heat-related stimulus (incrementally heated vs. isothermic chamber); mice freely explore both apparatus chambers. Here, we aim to determine whether the TIDAL conflict test reveals in mice underappreciated sex differences in anxiety and/or heat sensitivity. We establish in four distinct experiments that females on the TIDAL conflict test persist substantially longer on the dark-heated plate, suggesting that female mice exhibit elevated anxiety-like behavior. Mice more strongly prefer the heated-dark plate on the TIDAL conflict test compared to control thermal place preference with both chambers illuminated. We also reveal that an anxiety-relieving drug, paroxetine, reduces mouse preference for the heating dark plate, supporting the validity of the TIDAL test. Therefore, our new TIDAL conflict test reliably unmasks the relative salience of anxiety (vs. heat sensitivity): mice that are female exhibit robust anxiety-like behaviors not consistently observed in classical tests. Future studies should incorporate TIDAL and other conflict tests to better understand rodent behavior and to identify mechanisms underlying anxiety and pain.

Promising strategies for the prevention of alcohol-related brain damage through optimised management of acute alcohol withdrawal: A focussed literature review

There is an increasing awareness of the link between chronic alcohol consumption and the development of cognitive, behavioural and functional deficits. Currently, preventative strategies are limited and require engagement in dedicated long-term rehabilitation and sobriety services, the availability of which is low. The acute alcohol withdrawal syndrome is an episode of neurochemical imbalance leading to autonomic dysregulation, increased seizure risk and cognitive disorientation. In addition to harm from symptoms of alcohol withdrawal (e.g. seizures), the underpinning neurochemical changes may also lead to cytotoxicity through various cellular mechanisms, which long-term, may translate to some of the cognitive impairments observed in Alcohol-Related Brain Damage (ARBD). Here we review some of the pharmacological and neurochemical mechanisms underpinning alcohol withdrawal. We discuss the cellular and pharmacological basis of various potential neuroprotective strategies that warrant further exploration in clinical populations with a view to preventing the development of ARBD. Such strategies, when integrated into the clinical management of acute alcohol withdrawal, may impact large populations of individuals, who currently face limited dedicated service delivery and healthcare resource.

High Blood Pressure and Impaired Brain Health: Investigating the Neuroprotective Potential of Magnesium

High blood pressure (BP) is a significant contributor to the disease burden globally and is emerging as an important cause of morbidity and mortality in the young as well as the old. The well-established impact of high BP on neurodegeneration, cognitive impairment, and dementia is widely acknowledged. However, the influence of BP across its full range remains unclear. This review aims to explore in more detail the effects of BP levels on neurodegeneration, cognitive function, and dementia. Moreover, given the pressing need to identify strategies to reduce BP levels, particular attention is placed on reviewing the role of magnesium (Mg) in ageing and its capacity to lower BP levels, and therefore potentially promote brain health. Overall, the review aims to provide a comprehensive synthesis of the evidence linking BP, Mg and brain health. It is hoped that these insights will inform the development of cost-effective and scalable interventions to protect brain health in the ageing population.

GABAA receptor subunit M2-M3 linkers have asymmetric roles in pore gating and diazepam modulation

GABAA receptors (GABAARs) are neurotransmitter-gated ion channels critical for inhibitory synaptic transmission as well as the molecular target for benzodiazepines (BZDs), one of the most widely prescribed class of psychotropic drugs today. Despite structural insight into the conformations underlying functional channel states, the detailed molecular interactions involved in conformational transitions and the physical basis for their modulation by BZDs are not fully understood. We previously identified that alanine substitution at the central residue in the α1 subunit M2-M3 linker (V279A) enhances the efficiency of linkage between the BZD site and the pore gate. Here, we expand on this work by investigating the effect of alanine substitutions at the analogous positions in the M2-M3 linkers of β2 (I275A) and γ2 (V290A) subunits, which together with α1 comprise typical heteromeric α1β2γ2 synaptic GABAARs. We find that these mutations confer subunit-specific effects on the intrinsic pore closed-open equilibrium and its modulation by the BZD diazepam (DZ). The mutations α1(V279A) or γ2(V290A) bias the channel toward a closed conformation, whereas β2(I275A) biases the channel toward an open conformation to the extent that the channel becomes leaky and opens spontaneously in the absence of agonist. In contrast, only α1(V279A) enhances the efficiency of DZ-to-pore linkage, whereas mutations in the other two subunits have no effect. These observations show that the central residue in the M2-M3 linkers of distinct subunits in synaptic α1β2γ2 GABAARs contribute asymmetrically to the intrinsic closed-open equilibrium and its modulation by DZ.

Sleep promoting and omics exploration on probiotics fermented Gastrodia elata Blume

Fermenting Chinese medicinal herbs could enhance their bioactivities. We hypothesized probiotic-fermented gastrodia elata Blume (GE) with better potential to alleviate insomnia than that of unfermented, thus the changes in chemical composition and the insomnia-alleviating effects and mechanisms of fermented GE on pentylenetetrazole (PTZ)-induced insomnia zebrafish were explored via high-performance liquid chromatography (HPLC) and mass spectroscopy-coupled HPLC (HPLC-MS), phenotypic, transcriptomic, and metabolomics analysis. The results demonstrated that probiotic fermented GE performed better than unfermented GE in increasing the content of chemical composition, reducing the displacement, average speed, and number of apoptotic cells in zebrafish with insomnia. Metabolomic investigation showed that the anti-insomnia effect was related to regulating the pathways of actin cytoskeleton and neuroactive ligand-receptor interactions. Transcriptomic and reverse transcription qPCR (RT-qPCR) analysis revealed that secondary fermentation liquid (SFL) significantly modulated the expression levels of neurod1, msh2, msh3, recql4, ercc5, rad5lc, and rev3l, which are mainly involved in neuron differentiation and DNA repair. Collectively, as a functional food, fermented GE possessed potential for insomnia alleviation.

Parenteral medication for the management of acute severe behavioural disturbance (ASBD) in the emergency department

OBJECTIVES

This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To assess the effectiveness and safety profiles of different parenteral medications for the management of acute severe behavioural disturbance in the emergency department setting. These medications are required following the failure of less restrictive means of controlling the patient's behavioural disturbance.

Effects of chronic diazepam exposure on the behaviors and oxidative stress homeostasis in the eyes and brains of female Japanese medaka

Diazepam (DZP) residue has been frequently detected in wastewater, surface water, and groundwater due to its extensive use over the decades. In this study, we exposed female Japanese medaka (Oryzias latipes) to environmentally relevant doses of DZP (800 and 8000 ng/L) for 4 weeks, aimed to investigate their behavioral responses and possible links with ocular and brain oxidative stress homeostasis. As a result, DZP exposure could significantly reduce swimming activity (800 ng/L) and anxiety (800 and 8000 ng/L), indicating a sedative effect on medaka. The DZP exposure also significantly increased the social interaction in medaka at 8000 ng/L. Furthermore, exposure to DZP could alter the ocular and brain oxidative stress homeostasis in medaka. The ocular CAT activities significantly increased in the 800 ng/L-DZP groups, and the brain SOD, CAT, GST and MDA levels also significantly increased in both DZP exposure groups. Correlation analysis revealed that the ocular and brain oxidative stress induced by DZP exposure might play an important role in their behavioral toxicity to medaka. Our findings highlight the necessity to clarify the exact link between DZP exposure-induced oxidative stress in the neural and sensor systems and its behavioral toxicity to better assess the risks on nontarget aquatic species.

Discriminative-stimulus effects of cannabidiol oil in Sprague-Dawley rats

Cannabidiol (CBD) is one of the major centrally active phytocannabinoid components of cannabis, and has been approved by the FDA only for the treatment of seizures associated with three rare disorders. It has also been touted as a potential treatment for anxiety in place of more traditional treatments like benzodiazepines. Although there is some evidence of anxiolytic effects of CBD, its suitability as a substitute for benzodiazepines is unknown. This experiment was designed to assess the extent to which CBD shares interoceptive discriminative-stimulus properties with the anxiolytic drug chlordiazepoxide (CDP), a benzodiazepine. In the present experiment, a range of doses (0-1569 mg/kg) of over-the-counter CBD oil was administered (i.g.) in male Sprague-Dawley rats trained to discriminate 5.6 mg/kg CDP from saline. Due to the long time-course effects of CBD, generalization tests were conducted at 90 and 120 min post-CBD administration. The two highest doses of CBD tested (1064 and 1569 mg/kg) were found to partially substitute for 5.6 mg/kg CDP, with mean percent responding on the CDP-associated lever reaching above 20% at time 2 (120 min post-CBD administration), suggesting that high doses of the over-the-counter CBD oils used in this experiment share interoceptive discriminative-stimulus properties to some degree with CDP. These results are novel in comparison to existing research into stimulus effects of CBD, in which substitution for benzodiazepines has not previously been observed.

A real-world pharmacovigilance study of FDA adverse event reporting system events for diazepam

Background: Diazepam, one of the benzodiazepines, is widely used clinically to treat anxiety, for termination of epilepsy, and for sedation. However, the reports of its adverse events (AEs) have been numerous, and even fatal complications have been reported. In this study, we investigated the AEs of diazepam based on real data from the U.S. Food and Drug Administration (FDA) adverse event reporting system (FAERS). Methods: Disproportionality in diazepam-associated AEs was assessed through the calculation of reporting odds ratios (RORs), proportional reporting ratios (PRRs), Bayesian confidence-propagation neural networks (BCPNNs), and gamma-Poisson shrinkage (GPS). Results: Among the 19,514,140 case reports in the FAERS database, 15,546 reports with diazepam as the "principal suspect (PS)" AEs were identified. Diazepam-induced AEs occurred targeting 27 system organ categories (SOCs). Based on four algorithms, a total of 391 major disproportionate preferred terms (PTs) were filtered out. Unexpectedly significant AEs such as congenital nystagmus, developmental delays, and rhabdomyolysis were noted, which were not mentioned in the drug insert. Conclusion: Our study identified potential signals of new AEs that could provide strong support for clinical monitoring and risk identification of diazepam.

Eco-friendly electrochemical sensor for determination of conscious sedating drug "midazolam'' based on Au-NPs@Silica modified carbon paste electrode

Benzodiazepines (BZDs) are a group of drugs prescribed for their sedating effect. Their misuse and addictive properties stipulate different authorities for developing simple, fast and accurate analytical methods for instantaneous detection. Differential pulse voltammetric technique (DPV) was utilized for the selective assay of midazolam hydrochloride (MDZ) in the pure, parenteral dosage forms and plasma samples. A chemically modified carbon paste electrode (CPE) was implemented during the study. The method depended on the electroreduction of MDZ on the surface of the electrode over a potential range of 0.0 V to -1.6 V. The electrode was fabricated using silica nanoparticles (Si-NPs) which were incorporated into the composition of the CPE and used to enhance the electrode performance. Then, to enhance the sensitivity of the method, a chronoamperometric modification step was applied for depositing gold nanoparticles (Au-NPs) on the carbon paste electrode surface. Modification with Au-NPs showed a higher reduction current peak for MDZ with well-defined peaks. Various parameters such as pH of the media and measurements scan rate were investigated and optimized to enhance the sensor sensitivity. The sensor showed a dynamic linear response over a concentration range of 4.0 × 10-7 M to 2.9 × 10-4 M of MDZ with a LOD of 2.24 × 10-8 M using 0.1 M acetate buffer (pH 5.6). The sensor was validated in accordance with the ICH guidelines regarding accuracy, precision and specificity for the selective assay of MDZ in the presence of excipients. A greenness evaluation was performed using three different assessment tools, namely, the "Green Analytical Procedure Index" (GAPI), the "Analytical Greenness metric" (AGREE) and the "Whiteness Analytical Chemistry tool" (WAC) using the RGB12 model.

Magnesium (Mg2+): Essential Mineral for Neuronal Health: From Cellular Biochemistry to Cognitive Health and Behavior Regulation

Magnesium (Mg2+) is a crucial mineral involved in numerous cellular processes critical for neuronal health and function. This review explores the multifaceted roles of Mg2+, from its biochemical interactions at the cellular level to its impact on cognitive health and behavioral regulation. Mg2+ acts as a cofactor for over 300 enzymatic reactions, including those involved in ATP synthesis, nucleic acid stability, and neurotransmitter release. It regulates ion channels, modulates synaptic plasticity, and maintains the structural integrity of cell membranes, which are essential for proper neuronal signaling and synaptic transmission. Recent studies have highlighted the significance of Mg2+ in neuroprotection, showing its ability to attenuate oxidative stress, reduce inflammation, and mitigate excitotoxicity, thereby safeguarding neuronal health. Furthermore, Mg2+ deficiency has been linked to a range of neuropsychiatric disorders, including depression, anxiety, and cognitive decline. Supplementation with Mg2+, particularly in the form of bioavailable compounds such as Magnesium-L-Threonate (MgLT), Magnesium-Acetyl-Taurate (MgAT), and other Magnesium salts, has shown some promising results in enhancing synaptic density, improving memory function, and alleviating symptoms of mental health disorders. This review highlights significant current findings on the cellular mechanisms by which Mg2+ exerts its neuroprotective effects and evaluates clinical and preclinical evidence supporting its therapeutic potential. By elucidating the comprehensive role of Mg2+ in neuronal health, this review aims to underscore the importance of maintaining optimal Mg2+ levels for cognitive function and behavioral regulation, advocating for further research into Mg2+ supplementation as a viable intervention for neuropsychiatric and neurodegenerative conditions.

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.

Proposed anti-seizure medication combinations with rufinamide in the treatment of Lennox-Gastaut syndrome: Narrative review and expert opinion

Lennox-Gastaut syndrome (LGS) is a severe, chronic, complex form of early childhood-onset epilepsy characterized by multiple seizure types, generalized slow (≤2.5 Hz) spike-and-wave activity and other electroencephalography abnormalities, and cognitive impairment. A key treatment goal is early seizure control, and several anti-seizure medications (ASMs) are available. Due to the low success rate in achieving seizure control with monotherapy and an absence of efficacy data supporting any particular combination of ASMs for treating LGS, a rational approach to selection of appropriate polytherapy should be applied to maximize benefit to patients. Such "rational polytherapy" involves consideration of factors including safety (including boxed warnings), potential drug-drug interactions, and complementary mechanisms of action. Based on the authors' clinical experience, rufinamide offers a well-considered first adjunctive therapy for LGS, particularly in combination with clobazam and other newer agents for LGS, and may be particularly useful for reducing the frequency of tonic-atonic seizures associated with LGS.

Treatment of cholinergic-induced status epilepticus with polytherapy targeting GABA and glutamate receptors

Despite new antiseizure medications, the development of cholinergic-induced refractory status epilepticus (RSE) continues to be a therapeutic challenge as pharmacoresistance to benzodiazepines and other antiseizure medications quickly develops. Studies conducted by Epilepsia. 2005;46:142 demonstrated that the initiation and maintenance of cholinergic-induced RSE are associated with trafficking and inactivation of gamma-aminobutyric acid A receptors (GABAA R) thought to contribute to the development of benzodiazepine pharmacoresistance. In addition, Dr. Wasterlain's laboratory reported that increased N-methyl-d-aspartate receptors (NMDAR) and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPAR) contribute to enhanced glutamatergic excitation (Neurobiol Dis. 2013;54:225; Epilepsia. 2013;54:78). Thus, Dr. Wasterlain postulated that targeting both maladaptive responses of reduced inhibition and increased excitation that is associated with cholinergic-induced RSE should improve therapeutic outcome. We currently review studies in several animal models of cholinergic-induced RSE that demonstrate that benzodiazepine monotherapy has reduced efficacy when treatment is delayed and that polytherapy with drugs that include a benzodiazepine (eg midazolam and diazepam) to counter loss of inhibition, concurrent with an NMDA antagonist (eg ketamine) to reduce excitation provide improved efficacy. Improved efficacy with polytherapy against cholinergic-induced seizure is demonstrated by reduction in (1) seizure severity, (2) epileptogenesis, and (3) neurodegeneration compared with monotherapy. Animal models reviewed include pilocarpine-induced seizure in rats, organophosphorus nerve agent (OPNA)-induced seizure in rats, and OPNA-induced seizure in two mouse models: (1) carboxylesterase knockout (Es1-/- ) mice which, similarly to humans, lack plasma carboxylesterase and (2) human acetylcholinesterase knock-in carboxylesterase knockout (KIKO) mice. We also review studies showing that supplementing midazolam and ketamine with a third antiseizure medication (valproate or phenobarbital) that targets a nonbenzodiazepine site rapidly terminates RSE and provides further protection against cholinergic-induced SE. Finally, we review studies on the benefits of simultaneous compared with sequential drug treatments and the clinical implications that lead us to predict improved efficacy of early combination drug therapies. The data generated from seminal rodent studies of efficacious treatment of cholinergic-induced RSE conducted under Dr. Wasterlain's guidance suggest that future clinical trials should treat the inadequate inhibition and temper the excess excitation that characterize RSE and that early combination therapies may provide improved outcome over benzodiazepine monotherapy.

Mutational Analysis of Anesthetic Binding Sites and Their Effects on GABAA Receptor Activation and Modulation by Positive Allosteric Modulators of the α7 Nicotinic Receptor

The positive allosteric modulators (PAMs) of the α7 nicotinic receptor N-(5-Cl-2-hydroxyphenyl)-N'-[2-Cl-5-(trifluoromethyl)phenyl]-urea (NS-1738) and (E)-3-(furan-2-yl)-N-(p-tolyl)-acrylamide (PAM-2) potentiate the α1β2γ2L GABAA receptor through interactions with the classic anesthetic binding sites located at intersubunit interfaces in the transmembrane domain of the receptor. In the present study, we employed mutational analysis to investigate in detail the involvement and contributions made by the individual intersubunit interfaces to receptor modulation by NS-1738 and PAM-2. We show that mutations to each of the anesthetic-binding intersubunit interfaces (β+/α-, α+/β-, and γ+/β-), as well as the orphan α+/γ- interface, modify receptor potentiation by NS-1738 and PAM-2. Furthermore, mutations to any single interface can fully abolish potentiation by the α7-PAMs. The findings are discussed in the context of energetic additivity and interactions between the individual binding sites.

Delayed tezampanel and caramiphen treatment but not midazolam protects against long-term neuropathology after soman exposure

Prolonged status epilepticus (SE) can cause brain damage; therefore, treatment must be administered promptly after seizure onset to limit SE duration and prevent neuropathology. Timely treatment of SE is not always feasible; this would be particularly true in a mass exposure to an SE-inducing agent such as a nerve agent. Therefore, the availability of anticonvulsant treatments that have neuroprotective efficacy even if administered with a delay after SE onset is an imperative. Here, we compared the long-term neuropathology resulting from acutely exposing 21-day-old male and female rats to the nerve agent soman, and treating them with midazolam (3 mg/kg) or co-administration of tezampanel (10 mg/kg) and caramiphen (50 mg/kg), at 1 h postexposure (~50 min after SE onset). Midazolam-treated rats had significant neuronal degeneration in limbic structures, mainly at one month postexposure, followed by neuronal loss in the basolateral amygdala and the CA1 hippocampal area. Neuronal loss resulted in significant amygdala and hippocampal atrophy, deteriorating from one to six months postexposure. Rats treated with tezampanel-caramiphen had no evidence of neuropathology, except for neuronal loss in the basolateral amygdala at the six-month timepoint. Anxiety was increased only in the midazolam-treated rats, at one, three, and six months postexposure. Spontaneous recurrent seizures appeared only in midazolam-treated rats, at three and six months postexposure in males and only at six months in females. These findings suggest that delayed treatment of nerve agent-induced SE with midazolam may result in long-lasting or permanent brain damage, while antiglutamatergic anticonvulsant treatment consisting of tezampanel and caramiphen may provide full neuroprotection.

Melatonin as a Chronobiotic with Sleep-promoting Properties

The use of exogenous melatonin (exo-MEL) as a sleep-promoting drug has been under extensive debate due to the lack of consistency of its described effects. In this study, we conduct a systematic and comprehensive review of the literature on the chronobiotic, sleep-inducing, and overall sleep-promoting properties of exo-MEL. To this aim, we first describe the possible pharmacological mechanisms involved in the sleep-promoting properties and then report the corresponding effects of exo-MEL administration on clinical outcomes in: a) healthy subjects, b) circadian rhythm sleep disorders, c) primary insomnia. Timing of administration and doses of exo-MEL received particular attention in this work. The exo-MEL pharmacological effects are hereby interpreted in view of changes in the physiological properties and rhythmicity of endogenous melatonin. Finally, we discuss some translational implications for the personalized use of exo-MEL in the clinical practice.

Magnesium and the Brain: A Focus on Neuroinflammation and Neurodegeneration

Magnesium (Mg) is involved in the regulation of metabolism and in the maintenance of the homeostasis of all the tissues, including the brain, where it harmonizes nerve signal transmission and preserves the integrity of the blood-brain barrier. Mg deficiency contributes to systemic low-grade inflammation, the common denominator of most diseases. In particular, neuroinflammation is the hallmark of neurodegenerative disorders. Starting from a rapid overview on the role of magnesium in the brain, this narrative review provides evidences linking the derangement of magnesium balance with multiple sclerosis, Alzheimer's, and Parkinson's diseases.

Fruits for Seizures? A Systematic Review on the Potential Anti-Convulsant Effects of Fruits and their Phytochemicals

Epilepsy is a devastating neurological disorder. Current anti-convulsant drugs are only effective in about 70% of patients, while the rest remain drug-resistant. Thus, alternative methods have been explored to control seizures in these drug-resistant patients. One such method may be through the utilization of fruit phytochemicals. These phytochemicals have been reported to have beneficial properties such as anti-convulsant, anti-oxidant, and anti-inflammatory activities. However, some fruits may also elicit harmful effects. This review aims to summarize and elucidate the anti- or pro-convulsant effects of fruits used in relation to seizures in hopes of providing a good therapeutic reference to epileptic patients and their carers. Three databases, SCOPUS, ScienceDirect, and PubMed, were utilized for the literature search. Based on the PRISMA guidelines, a total of 40 articles were selected for critical appraisal in this review. Overall, the extracts and phytochemicals of fruits managed to effectively reduce seizure activities in various preclinical seizure models, acting mainly through the activation of the inhibitory neurotransmission and blocking the excitatory neurotransmission. Only star fruit has been identified as a pro-convulsant fruit due to its caramboxin and oxalate compounds. Future studies should focus more on utilizing these fruits as possible treatment strategies for epilepsy.

Outcomes of patients treated with low-dose flumazenil for benzodiazepine detoxification: A description of 26 participants

INTRODUCTION

Benzodiazepines are commonly prescribed for a variety of indications and can be employed in the short- and long-term. While they are efficacious, issues arise from long-term use with the emergence of dependence and tolerance to doses within the therapeutic range and beyond. Discontinuation from benzodiazepines can be problematic for patients and may result in a withdrawal syndrome, which can be protracted and last months to years.

METHODS

26 participants received low-dose subcutaneous flumazenil infusions (4 mg/24 h for approximately eight days) as part of a randomised control crossover trial. Return to benzodiazepine use was assessed monthly for three months based on the benzodiazepine use in the previous week. Where data was not available, the treating psychiatrist examined patient files and clinical documents to determine benzodiazepine use. Withdrawal and craving scores were also measured.

RESULTS

Abstinence rates from benzodiazepines at one-, two-, and three-month follow ups were 65.4 %, 50.0 %, and 46.2 % respectively. When considering patient files and clinical documents for those lost to follow-up, abstinence rates were higher at 73.1 %, 65.4 % and 61.5 % at the one-, two-, and three-month follow ups respectively. Withdrawal and craving scores were higher in those that had returned to any benzodiazepine use.

CONCLUSION

Self-reported rates of abstinence from benzodiazepines at three months was between 46.2 % and 61.5 %. Flumazenil may yield greater success than benzodiazepine tapering from high dose benzodiazepine use (≥30 mg diazepam equivalent). Further research should compare abstinence rates after treatment with flumazenil compared to benzodiazepine tapering in high dose benzodiazepine users.

Antiseizure and Neuroprotective Efficacy of Midazolam in Comparison with Tezampanel (LY293558) against Soman-Induced Status Epilepticus

Acute exposure to nerve agents induces status epilepticus (SE), which can cause death or long-term brain damage. Diazepam is approved by the FDA for the treatment of nerve agent-induced SE, and midazolam (MDZ) is currently under consideration to replace diazepam. However, animal studies have raised questions about the neuroprotective efficacy of benzodiazepines. Here, we compared the antiseizure and neuroprotective efficacy of MDZ (5 mg/kg) with that of tezampanel (LY293558; 10 mg/kg), an AMPA/GluK1 receptor antagonist, administered 1 h after injection of the nerve agent, soman (1.2 × LD50), in adult male rats. Both of the anticonvulsants promptly stopped SE, with MDZ having a more rapid effect. However, SE reoccurred to a greater extent in the MDZ-treated group, resulting in a significantly longer total duration of SE within 24 h post-exposure compared with the LY293558-treated group. The neuroprotective efficacy of the two drugs was studied in the basolateral amygdala, 30 days post-exposure. Significant neuronal and inter-neuronal loss, reduced ratio of interneurons to the total number of neurons, and reduction in spontaneous inhibitory postsynaptic currents accompanied by increased anxiety were found in the MDZ-treated group. The rats treated with LY293558 did not differ from the control rats (not exposed to soman) in any of these measurements. Thus, LY293558 has significantly greater efficacy than midazolam in protecting against prolonged seizures and brain damage caused by acute nerve agent exposure.

Analysis of Medication Rule of Primary Epilepsy Based on Xiaocheng Yan’s Clinical Experience Collection of Epilepsy

Objective

To explore and analyze the medication rule of Professor Xiaocheng Yan in the treatment of primary epilepsy, hoping to provide reference for the clinical treatment of primary epilepsy.

Methods

Mining and analysis of Professor Xiaocheng Yan sorted out the medical cases of primary epilepsy in Xiaocheng Yan's clinical experience collection of epilepsy, extracted the traditional Chinese medicine (TCM) prescription data in the medical cases, standardized the obtained TCM prescription data, and used the data mining function integrated by the ancient and modern medical case cloud platform V2.3.5 to carry out frequency statistics, cluster analysis, association analysis, and complex network analysis on the TCM data, and the common herbs used by Professor Xiaocheng Yan in the treatment of primary epilepsy, properties and classifications of commonly used herbs, pairs of commonly used herbs, and core prescriptions were obtained.

Results

A total of 39 cases, 228 medical records, and 230 prescriptions data of TCM were included. A total of 96 Chinese medicinal herbs were involved, and the total frequency of medication was 3,828. High-frequency herbs include Rhizoma Gastrodiae (Tianma) (222 times), Ramulus Uncariae cum Uncis (Gouteng) (220 times), Rhizoma Acori Tatarinowii (Shichangpu) (216 times), Rhizoma Pinelliae Praeparatum (Fabanxia) (207 times), Bombyx Batryticatus (Jiangcan) (206 times), and Periostracum Cicadae (Chantui) (181 times). The main properties and flavors of commonly used Chinese medicinal herbs were sweet, bitter, and pungent, which were mainly attributed to the four meridians of liver, lung, heart, and spleen. Commonly used couplet herbs were {Periostracum Cicadae (Chantui)} ≥ {Bombyx Batryticatus (Jiangcan)}, {Rhizoma Acori Tatarinowii (Shichangpu)} ≥{ Bombyx Batryticatus (Jiangcan)}, {Radix Bupleuri (Chaihu)} ≥ {Radix Scutellariae (Huangqin)}, {Rhizoma Gastrodiae (Tianma)} ≥ {Ramulus Uncariae cum Uncis (Gouteng)}, {Rhizoma Acori Tatarinowii (Shichangpu)} ≥ {Periostracum Cicadae (Chantui)}, {Ramulus Uncariae cum Uncis (Gouteng)} ≥ {Bombyx Batryticatus (Jiangcan)}, {Bombyx Batryticatus (Jiangcan)} ≥ {Rhizoma Gastrodiae (Tianma)}, {Rhizoma Acori Tatarinowii (Shichangpu)} ≥ {Ramulus Uncariae cum Uncis (Gouteng)}, etc. The core prescription composition was based on the addition and subtraction of Tianma Gouteng decoction and Erchen decoction. The main pharmacological mechanisms of core prescriptions are mainly reflected in antioxidation, enhancing GABA efficacy, and regulating NMDA channel and sodium channel, neuroprotection, and so on.

Conclusion

Professor Xiaocheng Yan's medication for the treatment of primary epilepsy was based on the principle of relieving wind and spasm, drying dampness and resolving phlegm, giving consideration to both Qi and blood, and harmonizing liver, lung, heart, and spleen.

Physiologically-Based Pharmacokinetic and Pharmacodynamic Modeling of Diazepam: Unbound Interstitial Brain Concentrations Correspond to Clinical Endpoints

Benzodiazepines induce a series of clinical effects by modulating subtypes of GABA_A receptors in the central nervous system. The brain concentration-time profiles of diazepam that correspond to these effects are unknown, but can be estimated with physiologically-based pharmacokinetic (PBPK) modeling. In this study, a PBPK model for the 1,4-benzodiazepines diazepam and nordiazepam was developed from plasma concentration time-courses with PK-Sim^® software to predict brain concentrations. The PBPK model simulations accurately parallel plasma concentrations from both an internal model training data set and an external data set for both intravenous and peroral diazepam administrations. It was determined that the unbound interstitial brain concentration-time profiles correlated with diazepam pharmacodynamic endpoints. With a 30 mg intravenous diazepam dose, the peak unbound interstitial brain concentration from this model is 160 nM at 2 minutes and 28.9 nM at 120 minutes. Peak potentiation of recombinant GABA_A receptors composed of α1β2γ2s, α2β2γ2s, and α5β2γ2s subunit combinations that are involved in diazepam clinical endpoints is 108%, 139% and 186%, respectively, with this intravenous dose. With 10 mg peroral administrations of diazepam delivered every 24 hours, steady-state peak and trough unbound interstitial brain diazepam concentrations are 22.3 ± 7.5 nM and 9.3 ± 3.5 nM. Nordiazepam unbound interstitial brain concentration is 36.1 nM at equilibrium with this diazepam dosing schedule. Pharmacodynamic models coupled to the diazepam unbound interstitial brain concentrations from the PBPK analysis account for electroencephalographic drug effect, change in 13-30 Hz electroencephalographic activity, amnesia incidence, and sedation score time-courses from human subjects. This article is protected by copyright. All rights reserved.

The cross-sectional association of frailty with chronic past and current use of benzodiazepine drugs

BACKGROUND

Frailty, a clinical syndrome characterized by vulnerability to stressors resulting from multisystemic loss of physiological reserve. The use of benzodiazepines in older adults has been associated with confusion, sedation, and cognitive impairment, which in turn may lead to frailty.

AIMS

The purpose of this study was to determine the cross-sectional association between frailty and chronic past or current use of benzodiazepine drugs among older US Veterans.

METHODS/DESIGN

This is a cross-sectional study of community-dwelling older Veterans who had determinations of frailty. Benzodiazepine prescription data were obtained via EHR. A 31-item VA Frailty Index (VA-FI) was generated at the time of the assessment. We categorized Veterans into robust (FI ≤ 0.10), pre-frail (FI 0.10-0.21), and Frail (FI ≥ 0.21). After adjusting for sociodemographic characteristics, we calculated ORs and 95% CIs using a binomial logistic regression (BLR) model to assess the cross-sectional association between benzodiazepine use and frailty.

RESULTS

Population sample consisted of 17,423 Veterans, mean age 75.53 (SD = 8.03) years, 70.80% Caucasian, 97.34% male, 14,545 (83.50%) patients were non-users of benzodiazepine drugs, 2408 (13.80%) had a past use, and 470 (2.70%) were current users. In BLR, individuals with past (OR 2.51, 95% CI 2.30-2.74, p < .001) or current (OR 2.36, 95% CI 1.96-2.83, p < .001) use showed a higher association with frailty as compared to individuals who were non-users.

CONCLUSIONS

The use of benzodiazepine was cross-sectionally associated with frailty in older Veterans. These results suggest that screening for frailty in patients with past or current exposure to benzodiazepine medications may be necessary for proper management.

The Presence of Blood-Brain Barrier Modulates the Response to Magnesium Salts in Human Brain Organoids

Magnesium (Mg) is fundamental in the brain, where it regulates metabolism and neurotransmission and protects against neuroinflammation. To obtain insights into the molecular basis of Mg action in the brain, we investigated the effects of Mg in human brain organoids, a revolutionary 3D model to study neurobiology and neuropathology. In particular, brain organoids derived from human induced pluripotent stem cells were cultured in the presence or in the absence of an in vitro-generated blood–brain barrier (BBB), and then exposed to 1 or 5 mM concentrations of inorganic and organic Mg salts (Mg sulphate (MgSO₄); Mg pidolate (MgPid)). We evaluated the modulation of NMDA and GABAergic receptors, and BDNF. Our data suggest that the presence of the BBB is essential for Mg to exert its effects on brain organoids, and that 5 mM of MgPid is more effective than MgSO₄ in increasing the levels of GABA receptors and BDNF, and decreasing those of NMDA receptor. These results might illuminate novel pathways explaining the neuroprotective role of Mg.

Elucidating Pathway and Anesthetic Mechanism of Action of Clove Oil Nanoformulations in Fish

Clove oil (CO), an essential oil of Syzygium aromaticum, has been reported as an anesthetic for many fish species. However, its insoluble properties require a suitable delivery system for its application. In the present study, nanoformulations of CO as a nanoemulsion (CO-NE), a self-microemulsifying drug-delivery system (CO-SMEDDS), and a self-nanoemulsifying drug-delivery system (CO-SNEDDS) were prepared for delivering CO. Zebrafish were used as a fish model to investigate oil pathways. The result shows fluorescence spots of fluorescence-labeled CO accumulate on the gills, skin, and brain. All CO nanoformulations significantly increased penetration flux compared to CO ethanolic solution. Investigation of the anesthetic mechanism of action using a rat brain γ-aminobutyric acid subtype A (GABA_A) receptor-binding test demonstrates that CO and its major compound, eugenol, modulate [³H]muscimol binding. CO-NE exhibited a concentration-dependent binding activity with an EC₅₀ value of 175 µg/mL, significantly higher than CO solution in dimethyl sulfoxide. In conclusion, CO enters the fish through the skin and gills. The anesthetic mechanism of action of CO is based on modulation of [³H] muscimol binding to GABA_A receptors. Among three nanoformulations tested, CO-NE is the most effective at increasing permeability and enhancing the receptor-binding activity of the oil.

A novel graph mining approach to predict and evaluate food-drug interactions

Food-drug interactions (FDIs) arise when nutritional dietary consumption regulates biochemical mechanisms involved in drug metabolism. This study proposes FDMine, a novel systematic framework that models the FDI problem as a homogenous graph. Our dataset consists of 788 unique approved small molecule drugs with metabolism-related drug-drug interactions and 320 unique food items, composed of 563 unique compounds. The potential number of interactions is 87,192 and 92,143 for disjoint and joint versions of the graph. We defined several similarity subnetworks comprising food-drug similarity, drug-drug similarity, and food-food similarity networks. A unique part of the graph involves encoding the food composition as a set of nodes and calculating a content contribution score. To predict new FDIs, we considered several link prediction algorithms and various performance metrics, including the precision@top (top 1%, 2%, and 5%) of the newly predicted links. The shortest path-based method has achieved a precision of 84%, 60% and 40% for the top 1%, 2% and 5% of FDIs identified, respectively. We validated the top FDIs predicted using FDMine to demonstrate its applicability, and we relate therapeutic anti-inflammatory effects of food items informed by FDIs. FDMine is publicly available to support clinicians and researchers.

Benzodiazepines: Uses, Dangers, and Clinical Considerations

Benzodiazepines (BZDs) are among one of the most widely prescribed drug classes in the United States. BZDs are a class of psychoactive drugs known for their depressant effect on the central nervous system (CNS). They quickly diffuse through the blood-brain barrier to affect the inhibitory neurotransmitter GABA and exert sedative effects. Related to their rapid onset and immediate symptom relief, BZDs are used for those struggling with sleep, anxiety, spasticity due to CNS pathology, muscle relaxation, and epilepsy. One of the debilitating side effects of BZDs is their addictive potential. The dependence on BZDs generally leads to withdrawal symptoms, requiring careful tapering of the medication when prescribed. Regular use of BZDs has been shown to cause severe, harmful psychological and physical dependence, leading to withdrawal symptoms similar to that of alcohol withdrawal. Some of these withdrawal symptoms can be life threatening. The current treatment for withdrawal is through tapering with clonazepam. Many drugs have been tested as a treatment for withdrawal, with few proving efficacious in randomized control trials. Future research is warranted for further exploration into alternative methods of treating BZD withdrawal. This call to action proves especially relevant, as those seeking treatment for BZD dependence and withdrawal are on the rise in the United States.

Toxicogenomic differentiation of functional responses to fipronil and imidacloprid in Daphnia magna

Active substances of pesticides, biocides or pharmaceuticals can induce adverse side effects in the aquatic ecosystem, necessitating environmental hazard and risk assessment prior to substance registration. The freshwater crustacean Daphnia magna is a model organism for acute and chronic toxicity assessment representing aquatic invertebrates. However, standardized tests involving daphnia are restricted to the endpoints immobility and reproduction and thus provide only limited insights into the underlying modes-of-action. Here, we applied transcriptome profiling to a modified D. magna Acute Immobilization test to analyze and compare gene expression profiles induced by the GABA-gated chloride channel blocker fipronil and the nicotinic acetylcholine receptor (nAChR) agonist imidacloprid. Daphnids were expose to two low effect concentrations of each substance followed by RNA sequencing and functional classification of affected gene ontologies and pathways. For both insecticides, we observed a concentration-dependent increase in the number of differentially expressed genes, whose expression changes were highly significantly positively correlated when comparing both test concentrations. These gene expression fingerprints showed virtually no overlap between the test substances and they related well to previous data of diazepam and carbaryl, two substances targeting similar molecular key events. While, based on our results, fipronil predominantly interfered with molecular functions involved in ATPase-coupled transmembrane transport and transcription regulation, imidacloprid primarily affected oxidase and oxidoreductase activity. These findings provide evidence that systems biology approaches can be utilized to identify and differentiate modes-of-action of chemical stressors in D. magna as an invertebrate aquatic non-target organism. The mechanistic knowledge extracted from such data will in future contribute to the development of Adverse Outcome Pathways (AOPs) for read-across and prediction of population effects.

The Role of Phospholipase C in GABAergic Inhibition and Its Relevance to Epilepsy

Epilepsy is characterized by recurrent seizures due to abnormal hyperexcitation of neurons. Recent studies have suggested that the imbalance of excitation and inhibition (E/I) in the central nervous system is closely implicated in the etiology of epilepsy. In the brain, GABA is a major inhibitory neurotransmitter and plays a pivotal role in maintaining E/I balance. As such, altered GABAergic inhibition can lead to severe E/I imbalance, consequently resulting in excessive and hypersynchronous neuronal activity as in epilepsy. Phospholipase C (PLC) is a key enzyme in the intracellular signaling pathway and regulates various neuronal functions including neuronal development, synaptic transmission, and plasticity in the brain. Accumulating evidence suggests that neuronal PLC is critically involved in multiple aspects of GABAergic functions. Therefore, a better understanding of mechanisms by which neuronal PLC regulates GABAergic inhibition is necessary for revealing an unrecognized linkage between PLC and epilepsy and developing more effective treatments for epilepsy. Here we review the function of PLC in GABAergic inhibition in the brain and discuss a pathophysiological relationship between PLC and epilepsy.

Direct Structural Insights into GABAA Receptor Pharmacology

GABA_A receptors are pentameric ligand-gated ion channels that mediate most fast neuronal inhibition in the brain. In addition to their important physiological roles, they are noteworthy in their rich pharmacology; prominent drugs used for anxiety, insomnia, and general anesthesia act through positive modulation of GABA_A receptors. Direct structural information for how these drugs work was absent until recently. Efforts in structural biology over the past few years have revealed how important drug classes and natural products interact with the GABA_A receptor, providing a foundation for studies in dynamics and structure-guided drug design. Here, we review recent developments in GABA_A receptor structural pharmacology, focusing on subunit assemblies of the receptor found at synapses.

A critical residue in the α1M2-M3 linker regulating mammalian GABAA receptor pore gating by diazepam

Benzodiazepines (BZDs) are a class of widely prescribed psychotropic drugs that modulate activity of GABA_A receptors (GABA_ARs), neurotransmitter-gated ion channels critical for synaptic transmission. However, the physical basis of this modulation is poorly understood. We explore the role of an important gating domain, the α₁M2–M3 linker, in linkage between the BZD site and pore gate. To probe energetics of this coupling without complication from bound agonist, we use a gain of function mutant (α₁L9'Tβ₂γ_2L) directly activated by BZDs. We identify a specific residue whose mutation (α₁V279A) more than doubles the energetic contribution of the BZD positive modulator diazepam (DZ) to pore opening and also enhances DZ potentiation of GABA-evoked currents in a wild-type background. In contrast, other linker mutations have little effect on DZ efficiency, but generally impair unliganded pore opening. Our observations reveal an important residue regulating BZD-pore linkage, thereby shedding new light on the molecular mechanism of these drugs.

Anti-anxiety properties of selected medicinal plants

Exploration of new drugs targeting anxiety treatment is a major concern worldwide. Medicinal plants are being used as a potential source of novel drugs for anxiety disorders. The objective of this review is to provide information about the healing outcomes of anxiety treatment with natural products. Valeriana officinalis, Citrus aurantium, Commelina benghalensis, Achyranthes aspera, Mimosa pudica, Achillea millefolium, Nymphaea alba, Leonurus cardiac, Camellia sinensis, Turnera aphrodisiaca, Crataegus oxyacantha and Piper methysticum showed promising effects on anxiety in animal models. In clinical studies, passion flower, kava, valerian, St John's wort, and ashwagandha showed the most positive results. More studies are needed for the exploration of the anti-anxiety of medicinal plants. In drugs derived from natural sources have explored many components that are playing an essential role in curing anxiety disorders and associated complications.

Is the unique benzodiazepine structure interacting with CYP enzymes to affect steroid synthesis in vitro?

The aim of this project was to investigate the endocrine disrupting effects of three γ-aminobutyric acid type A receptor (GABA_AR) agonists, diazepam (DZ), oxazepam (OX) and alprazolam (AL) using the steroidogenic in vitro H295R cell line assay, a recombinant CYP17A1 assay, qPCR analysis and computational modelling. Similar effects for DZ and OX on the steroidogenesis were observed in the H295R experiment at therapeutically relevant concentrations. Progestagens and corticosteroids were increased up to 10 fold and androgens were decreased indicating CYP17A1 lyase inhibition. For DZ the inhibition on both the hydroxylase and lyase was confirmed by the recombinant CYP17A1 assay, whereas OX did not appear to directly affect the recombinant CYP17A1 enzyme. Androgens were decreased when exposing the H295R cells to AL, indicating a CYP17A1 lyase inhibition. However, this was not confirmed by the recombinant CYP17A1 assay but a down-regulation in gene expression was observed for StAR and CYP17A1. The present study showed that the three investigated benzodiazepines (BZDs) are rather potent endocrine disruptors in vitro, exerting endocrine effects close the therapeutic C_max. Both direct and indirect effects on steroidogenesis were observed, but molecular modelling indicated no direct interactions between the heme group in the steroidogenic CYP enzymes and the unique diazepin structure. In contrast, physicochemical properties such as high log P, structure and molecular weight similar to that of steroids appeared to influence the endocrine disrupting abilities of the investigated pharmaceuticals in vitro. Docking of the three BZDs in CYP17A1 and CYP21A2 confirmed that shape complementarity and hydrophobic effects seem to determine the binding modes.

Low dose γ radiation enhances antidepressant effect of resveratrol: Behavioral and neurochemical studies

The low dose of radiation (LDR) has received growing attention for its beneficial neuroprotective effect. This study was designed to investigate the enhancing effect of LDR on the antidepressant potential of resveratrol against diazepam-induced depression in mice. Female mice divided into five groups; control, diazepam (2 mg/kg), LDR (0.5Gy) + diazepam, resveratrol (20 mg/kg) + diazepam, LDR + resveratrol+diazepam. Mice received diazepam showed depressive symptoms as evidenced by decreased locomotor activity in the open field and increased immobility time in the forced swimming and tail suspension tests integrated with a marked decline in biogenic amines (serotonin, norepinephrine, and dopamine) in brain tissues. These effects were ameliorated by LDR or resveratrol administration demonstrating an antidepressant activity. Interestingly, LDR triggered the antidepressant effect of resveratrol as it restored the changes in behavioral tests, neurotransmitters, and neuro-histoarchitecture. In conclusion, these findings suggested that LDR could be considered as a novel adjuvant that augmented the resveratrol antidepressant effect and might serve as a potential therapeutic approach for depression.

Herbal medicines as anxiolytics prior to third molar surgical extraction. A randomized controlled clinical trial

OBJECTIVES

This study aimed to compare the effects of Passiflora incarnata, Erythrina mulungu, and midazolam in controlling anxiety in patients undergoing mandibular third molar extraction.

METHODS

The volunteers underwent extraction of their third mandibular molars in a randomized, placebo-controlled, triple-blind, and parallel clinical trial. Passiflora incarnata (500 mg), Erythrina mulungu (500 mg), or midazolam (15 mg) was orally administered 60 min before the surgery. The anxiety level of participants was evaluated using questionnaires and measurements of physical parameters, including heart rate (HR), blood pressure (BP), and oxygen saturation (SpO₂).

RESULTS

A total of 200 volunteers were included in this clinical trial. Considering each procedure independently, no significant differences (p > 0.05) in BP, HR, and SpO₂ were observed among the protocols.

CONCLUSIONS

Passiflora incarnata showed a similar effect to midazolam but differed from placebo and mulungu, which were unable to control anxiety in this situation. Therefore, the results suggest that Passiflora configures an herbal medicine with an anxiolytic effect, adequate to use in third molar extractions.

CLINICAL RELEVANCE

The use of Passiflora incarnata may be an alternative to benzodiazepines for controlling anxiety in patients scheduled for oral surgery under local anesthesia.

TRIAL REGISTRATION

ClinicalTrials.gov : ANSI-388.427.

Axonal mechanisms mediating γ-aminobutyric acid receptor type A (GABA-A) inhibition of striatal dopamine release

Axons of dopaminergic neurons innervate the striatum where they contribute to movement and reinforcement learning. Past work has shown that striatal GABA tonically inhibits dopamine release, but whether GABA-A receptors directly modulate transmission or act indirectly through circuit elements is unresolved. Here, we use whole-cell and perforated-patch recordings to test for GABA-A receptors on the main dopaminergic neuron axons and branching processes within the striatum of adult mice. Application of GABA depolarized axons, but also decreased the amplitude of axonal spikes, limited propagation and reduced striatal dopamine release. The mechanism of inhibition involved sodium channel inactivation and shunting. Lastly, we show the positive allosteric modulator diazepam enhanced GABA-A currents on dopaminergic axons and directly inhibited release, but also likely acts by reducing excitation from cholinergic interneurons. Thus, we reveal the mechanisms of GABA-A receptor modulation of dopamine release and provide new insights into the actions of benzodiazepines within the striatum.

To Approach or Avoid: An Introductory Overview of the Study of Anxiety Using Rodent Assays

Anxiety is a widely studied phenomenon in behavioral neuroscience, but the recent literature lacks an overview of the major conceptual framework underlying anxiety research to introduce young researchers to the field. In this mini-review article, which is aimed toward new undergraduate and graduate students, we discuss how researchers exploit the approach-avoidance conflict, an internal conflict rodents face between exploration of novel environments and avoidance of danger, to inform rodent assays that allow for the measurement of anxiety-related behavior in the laboratory. We review five widely-used rodent anxiety assays, consider the pharmacological validity of these assays, and discuss neural circuits that have recently been shown to modulate anxiety using the assays described. Finally, we offer related lines of inquiry and comment on potential future directions.

Anxiolytic like effect of L-Carnitine in mice: Evidences for the involvement of NO-sGC-cGMP signaling pathway

L-Carnitine (LC) is an endogenous compound synthesized from the essential amino acids lysine and methionine. LC act as an antioxidant and modulates the levels of neurochemicals such as glutamate, GABA, NO etc. implicated in the regulation of anxiety and related behavior. However its exact role in the anxiety is not known. The present study was designed to investigate the anxiolytic like effect of LC in mice. LC (2.5, 5.0 and 10 mg/kg, i.p.) was administered to the mice and the anxiety related behavior was determined using light and dark box (LDB) and elevated plus maze (EPM) tests. The whole brain nitrite level was also determined. The results obtained demonstrated that LC (10 mg/kg, i.p.) exerted anxiolytic like effect in mice, accompanied by the reduction of whole brain nitrite level significantly as compared to control. Further, the influence of NO and GABA modulators pretreatments on the effect of subtherapeutic dose of LC was also determined. The results obtained demonstrated that NO donor/cGMP modulator counteracted while NO inhibitor potentiated the effect confers by the subtherapeutic dose of LC mice. Pretreatment of diazepam (1 mg/kg, i.p.) further potentiated the effect of subtherapeutic dose of LC (5 mg/kg, i.p.) in EPM and LDB tests and further reduced the brain nitrite level significantly as compared to LC (5 mg/kg, i.p.) alone treatment. Thus, LC exerted anxiolytic like effect in mice and NO-sGC-cGMP signaling pathway influences the anxiolytic like effect of LC in mice.

Electroencephalographic analysis in soman-exposed 21-day-old rats and the effects of midazolam or LY293558 with caramiphen

Acute nerve agent exposure induces status epilepticus (SE), which can cause brain damage or death. Research aiming at developing effective therapies for controlling nerve agent-induced SE is commonly performed in adult rats. The characteristics of nerve agent-induced SE in young rats are less clear; relevant knowledge is necessary for developing effective pediatric therapies. Here, we have used electroencephalographic (EEG) recordings and analysis to study seizures in postnatal day 21 rats exposed to 1.2 × LD₅₀ of soman, and compared the antiseizure efficacy of midazolam (MDZ)-currently considered by the Food and Drug Administration to replace diazepam for treating SE in victims of nerve agent exposure-with that of LY293558, an AMPA/GluK1 receptor antagonist, administered in combination with caramiphen, an antimuscarinic with N-methyl-d-aspartate receptor antagonistic properties. Prolonged SE developed in 80% of the rats and was reflected in behavioral seizures/convulsions. Both MDZ and LY293558 + caramiphen stopped the SE induced by soman, but there was a significant recurrence of seizures within 24 h postexposure only in the MDZ-treated group, as revealed in the raw EEG data and their representation in the frequency domain using a fast Fourier transform and in spectral analysis over 24 hours. In contrast to the high efficacy of LY293558 + caramiphen, MDZ is not an effective treatment for SE induced by soman in young animals.

Application of the Co-Agonist Concerted Transition Model to Analysis of GABAA Receptor Properties

The co-agonist concerted transition model is a simple and practical solution to analyze various aspects of GABAA receptor function. Several model-based predictions have been verified experimentally in previous reports. We review here the practical implications of the model and demonstrate how it enables simplification of the experimental procedure and data analysis to characterize the effects of mutations or properties of novel ligands. Specifically, we show that the value of EC50 and the magnitude of current response are directly affected by basal activity, and that coapplication of a background agonist acting at a distinct site or use of a gain-of-function mutation can be employed to enable studies of weak activators or mutated receptors with impaired gating. We also show that the ability of one GABAergic agent to potentiate the activity elicited by another is a computable value that depends on the level of constitutive activity of the ion channel and the ability of each agonist to directly activate the receptor. Significantly, the model accurately accounts for situations where the paired agonists interact with the same site compared to distinct sites on the receptor.

GABAA Receptor β2E155 Residue Located at the Agonist-Binding Site Is Involved in the Receptor Gating

GABA_A receptors (GABA_ARs) play a crucial role in mediating inhibition in the adult brain. In spite of progress in describing (mainly) the static structures of this receptor, the molecular mechanisms underlying its activation remain unclear. It is known that in the α₁β₂γ_2L receptors, the mutation of the β₂E155 residue, at the orthosteric binding site, strongly impairs the receptor activation, but the molecular and kinetic mechanisms of this effect remain elusive. Herein, we investigated the impact of the β₂E155C mutation on binding and gating of the α₁β₂γ_2L receptor. To this end, we combined the macroscopic and single-channel analysis, the use of different agonists [GABA and muscimol (MSC)] and flurazepam (FLU) as a modulator. As expected, the β₂E155C mutation caused a vast right shift of the dose–response (for GABA and MSC) and, additionally, dramatic changes in the time course of current responses, indicative of alterations in gating. Mutated receptors showed reduced maximum open probability and enhanced receptor spontaneous activity. Model simulations for macroscopic currents revealed that the primary effect of the mutation was the downregulation of the preactivation (flipping) rate. Experiments with MSC and FLU further confirmed a reduction in the preactivation rate. Our single-channel analysis revealed the mutation impact mainly on the second component in the shut times distributions. Based on model simulations, this finding further confirms that this mutation affects mostly the preactivation transition, supporting thus the macroscopic data. Altogether, we provide new evidence that the β₂E155 residue is involved in both binding and gating (primarily preactivation).