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Taste buds contain 2 types of GABA-producing cells: sour-responsive Type III cells and glial-like Type I cells. The physiological role of GABA, released by Type III cells is not fully understood. Here, we investigated the role of GABA released from Type III cells using transgenic mice lacking the expression of GAD67 in taste bud cells (Gad67-cKO mice). Immunohistochemical experiments confirmed the absence of GAD67 in Type III cells of Gad67-cKO mice. Furthermore, no difference was observed in the expression and localization of cell type markers, ectonucleoside triphosphate diphosphohydrolase 2 (ENTPD2), gustducin, and carbonic anhydrase 4 (CA4) in taste buds between wild-type (WT) and Gad67-cKO mice. Short-term lick tests demonstrated that both WT and Gad67-cKO mice exhibited normal licking behaviors to each of the five basic tastants. Gustatory nerve recordings from the chorda tympani nerve demonstrated that both WT and Gad67-cKO mice similarly responded to five basic tastants when they were applied individually. However, gustatory nerve responses to sweet–sour mixtures were significantly smaller than the sum of responses to each tastant in WT mice but not in Gad67-cKO mice. In summary, elimination of GABA signalling by sour-responsive Type III taste cells eliminates the inhibitory cell–cell interactions seen with application of sour–sweet mixtures. [ABSTRACT FROM AUTHOR]

• Aberrant LHb hyperactivity drives susceptibility to depressive-like behaviors induced by maternal separation. • LHb IL-10 levels suppress neuronal activation and exert an anti-depressant effect. • IL-10 regulates the trafficking of LHb GABA A receptors and functions through PI3K/pAKT/gephyrin cascades. Maternal separation (MS), a form of early life adversity, increases the risk of psychiatric disorders in adulthood by intricately linking cytokines and mood-regulating brain circuits. The Lateral Habenula (LHb) encodes aversive experiences, contributes to negative moods, and is pivotal in depression development. However, the precise impact of MS on LHb cytokine signaling and synaptic plasticity remains unclear. We reported that adolescent MS offspring mice displayed susceptibility to depression behavioral phylotypes, with neuronal hyperactivity and an imbalance in pro-inflammatory and anti-inflammatory cytokines in the LHb. Moreover, the decreased IL-10 level negatively correlated with depressive-like behaviors in susceptible mice. Functionally, LHb IL-10 overexpression restored decreased levels of PI3K, phosphorylated AKT (pAKT), gephyrin, and membrane GABA A receptor proteins while reducing abnormally elevated GSK3β and Fos expression, rescuing the MS-induced depression. Conversely, LHb neuronal IL-10 receptor knockdown in naive mice increased Fos expression and elicited depression-like symptoms, potentially through impaired membrane GABA A receptor trafficking by suppressing the PI3K/pAKT/gephyrin cascades. Hence, this work establishes a mechanism by which MS promotes susceptibility to adolescent depression by impeding the critical role of IL-10 signaling on neuronal GABA A receptor function. [ABSTRACT FROM AUTHOR]

While there are numerous brain regions that have been shown to play a role in this AUD in humans and animal models, the central nucleus of the amygdala (CeA) has emerged as a critically important locus mediating binge alcohol consumption. In this study, we sought to understand how relative gene expression of key signaling molecules in the CeA changes during different periods of abstinence following bouts of binge drinking. To test this, we performed drinking in the dark (DID) on two separate cohorts of C57BL/6J mice and collected CeA brain tissue at 1 day (acute) and 7 days (protracted) abstinence after DID. We used qRTPCR to evaluate relative gene expression changes of 25 distinct genes of interest related to G protein-coupled receptors (GPCRs), neuropeptides, ion channel subunits, and enzymes that have been previously implicated in AUD. Our findings show that during acute abstinence CeA punches collected from female mice had upregulated relative mRNA expression of the gamma-aminobutyric acid receptor subunit alpha 2 (Gabra2), and the peptidase, angiotensinase c (Prcp). CeA punches from male mice at the same time point in abstinence had upregulated relative mRNA encoding for neuropeptide-related molecules, neuropeptide Y (Npy) and somatostatin (Sst), as well as the neuropeptide Y receptor Y2 (Npyr2), but downregulated Glutamate ionotropic receptor NMDA type subunit 1 (Grin1). After protracted abstinence, CeA punches collected from female mice had increased mRNA expression of corticotropin releasing hormone (Crh) and Npy. CeA punches collected from male mice at the same timepoint had upregulated relative mRNA expression of Npy2r, Npy, and Sst. Our findings support that there are differences in how the CeA of male and female mice respond to binge-alcohol exposure, highlighting the need to understand the implications of such differences in the context of AUD and binge drinking behavior. • There are differences in mRNA of alcohol related targets from the CeA of male and female mice. • There are differences in the time course mRNA of alcohol related targets from the CeA. • Correlations across genes are strongly modulated by sex. [ABSTRACT FROM AUTHOR]

We used virus-mediated anterograde and retrograde tracing, optogenetic modulation, immunostaining, in situ hybridization, and patch-clamp recordings in acute brain slices to study the release mechanism and µ-opioid modulation of the dual glutamatergic/GABAergic inputs from the ventral tegmental area and supramammillary nucleus to the granule cells of the dorsal hippocampus of male and female mice. In keeping with previous reports showing that the two transmitters are released by separate active zones within the same terminals, we found that the short-term plasticity and pharmacological modulation of the glutamatergic and GABAergic currents are indistinguishable. We further found that glutamate and GABA release at these synapses are both virtually completely mediated by N- and P/Q-type calcium channels. We then investigated µ-opioid modulation of these synapses and found that activation of µ-opioid receptors (MORs) strongly inhibits the glutamate and GABA release, mostly through inhibition of presynaptic N-type channels. However, the modulation by MORs of these dual synapses is complex, as it likely includes also a disinhibition due to downmodulation of local GABAergic interneurons which make direct axo-axonic contacts with the dual glutamatergic/GABAergic terminals. We discuss how this opioid modulation may enhance LTP at the perforant path inputs, potentially contributing to reinforce memories of drug-associated contexts. [ABSTRACT FROM AUTHOR]

In this work, we cloned and functionally expressed two novel GABAA receptor subunits from Procambarus clarkii crayfish. These two new subunits, PcGABAA‐α and PcGABAA‐β2, revealed significant sequence homology with the PcGABAA‐β subunit, previously identified in our laboratory. In addition, PcGABAA‐α subunit also shared a significant degree of identity with the Drosophila melanogaster genes DmGRD (GABA and glycine‐like receptor subunits of Drosophila) as well as PcGABAA‐β2 subunit with DmLCCH3 (ligand‐gated chloride channel homolog 3). Electrophysiological recordings showed that the expression in HEK cells of the novel subunits, either alone or in combination, failed to form functional homo‐ or heteromeric receptors. However, the co‐expression of PcGABAA‐α with PcGABAA‐β evoked sodium‐ or chloride‐dependent currents that accurately reproduced the time course of the GABA‐evoked currents in the X‐organ neurons from crayfish, suggesting that these GABA subunits combine to form two types of GABA receptors, one with cationic selectivity filter and the other preferentially permeates anions. On the other hand, PcGABAA‐β2 and PcGABAA‐β co‐expression generated a chloride current that does not show desensitization. Muscimol reproduced the time course of GABA‐evoked currents in all functional receptors, and picrotoxin blocked these currents; bicuculline did not block any of the recorded currents. Reverse transcription polymerae chain reaction (RT‐PCR) amplifications and FISH revealed that PcGABAA‐α and PcGABAA‐β2 are predominantly expressed in the crayfish nervous system. Altogether, these findings provide the first evidence of a neural GABA‐gated cationic channel in the crayfish, increasing our understanding of the role of these new GABAA receptor subunits in native heteromeric receptors. [ABSTRACT FROM AUTHOR]

As a continuation of our study in the field of GABAA receptor modulators, we report the design and synthesis of new pyrazolo[1,5-a]quinazoline (PQ) bearing at the 8-position an oxygen or nitrogen function. All the final compounds and some intermediates, showing the three different forms of the pyrazolo[1,5-a]quinazoline scaffold (5-oxo-4,5-dihydro, -4,5-dihydro, and heteroaromatic form), have been screened with an electrophysiological technique on recombinant GABAAR (α1β2γ2-GABAAR), expressed in Xenopus laevis oocytes, by evaluating the variation in produced chlorine current, and permitting us to identify some interesting compounds (6d, 8a, 8b, and 14) on which further functional assays were performed. Molecular modelling studies (docking, minimization of complex ligand–receptor, and MD model) and a statistical analysis by a Hierarchical Cluster Analysis (HCA) have collocated these ligands in the class corresponding to their pharmacological profile. The HCA results are coherent with the model we recently published (Proximity Frequencies), identifying the residues γThr142 and αHis102 as discriminant for the agonist and antagonist profile. [ABSTRACT FROM AUTHOR]

Aim. Molecular alterations of diabetic gastroenteropathy are poorly identified. This study investigates the effects of prolonged GABA supplementation on key protein expression levels of trypsin-1, PAR-1, PAR-2, PAR-3, PI3K, Akt, COX-2, GABAA, and GABAB receptors in the gastric tissue of type 2 diabetic rats (T2DM). Method: To induce T2DM, a 3-month high-fat diet and 35 mg/kg of streptozotocin was used. Twenty-four male Wistar rats were divided into 4 groups: (1) control, (2) T2DM, (3) insulin-treated (2.5 U/kg), and (4) GABA-treated (1.5 g/kg GABA). Blood glucose was measured weekly. The protein expressions were assessed using western blotting. Histopathological changes were examined by H&E and Masson's staining. Results: Diabetic rats show reduced NOS1 and elevated COX-2 and trypsin-1 protein expression levels in gastric tissue. Insulin and GABA therapy restored the NOS1 and COX-2 levels to control values. Insulin treatment increased PI3K, Akt, and p-Akt and, decreased trypsin-1, PAR-1, PAR-2, and PAR-3 levels in the diabetic rats. Levels of GABAA and GABAB receptors normalized following insulin and GABA therapy. H&E staining indicated an increase in mucin secretion following GABA treatment. Conclusion: These results suggest that GABA by acting on GABA receptors may regulate the trypsin-1/PARs/Akt/COX-2 pathway and thereby improve complications of diabetic gastroenteropathy. [ABSTRACT FROM AUTHOR]

To enhance the anesthetic efficacy and reduce toxic side effects, a strategy is proposed involving the utilization of general anesthetics of Propofol (Pro) and Etomidate (Eto) to synergistic inhibition GABA receptors simultaneously. Four‐in‐one molecular aggregates were prepared to implement this strategy, which comprised of Pro and Eto with the bridging molecule monoglyceride monooleate (GMO) and surfactant F127 through intermolecular forces. The blood‐brain barrier (BBB) targeted lactoferrin (LF) is affixed to their surface, obtaining the final molecular aggregates. By employing lactoferrin enrich aggregates to the BBB, followed by ultrasound combine microbubbles to open the BBB, a remarkable 4.5‐fold enhancement in brain drug delivery was achieved. The molecular aggregates group maintained stable parameters of heart rate, diastolic blood pressure, and systolic blood pressure. A notable increase of more than twice therapeutic index (TI) value was observed, implying their higher anesthesia efficiency and reduced toxicity. Electroencephalogram (EEG) experiments demonstrate a significant elevation in the proportion of δ waves from 28% to 80% for aggregates, accompanied by a nearly fivefold reduction in the proportion of θ waves, meaning a significant improvement in synergistic anesthesia effectiveness (interaction index 0.289) with lower drug dosage. Furthermore, mouse immunofluorescence brain slice experiments suggest Pro and Eto enter the GABA receptor simultaneously, resulting in synergistic inhibition of GABA receptors. [ABSTRACT FROM AUTHOR]

Background and Purpose Experimental Approach Key Results Conclusion and Implications Adenosine, through the A1 receptor (A1R), is an endogenous anticonvulsant. The development of adenosine receptor agonists as antiseizure medications has been hampered by their cardiac side effects. A moderately A1R‐selective agonist, MRS5474, has been reported to suppress seizures without considerable cardiac action. Hypothesizing that this drug could act through other than A1R and/or through a disease‐specific mechanism, we assessed the effect of MRS5474 on the hippocampus.Excitatory synaptic currents, field potentials, spontaneous activity, [3H]GABA uptake and GABAergic currents were recorded from rodent or human hippocampal tissue. Alterations in adenosine A3 receptor (A3R) density in human tissue were assessed by Western blot.MRS5474 (50–500 nM) was devoid of effect upon rodent excitatory synaptic signals in hippocampal slices, except when hyperexcitability was previously induced in vivo or ex vivo. MRS5474 inhibited GABA transporter type 1 (GAT‐1)‐mediated γ‐aminobutyric acid (GABA) uptake, an action not blocked by an A1R antagonist but blocked by an A3R antagonist and mimicked by an A3R agonist. A3R was overexpressed in human hippocampal tissue samples from patients with epilepsy that had focal resection from surgery. MRS5474 induced a concentration‐dependent potentiation of GABA‐evoked currents in oocytes micro‐transplanted with human hippocampal membranes prepared from epileptic hippocampal tissue but not from non‐epileptic tissue, an action blocked by an A3R antagonist.We identified a drug that activates A3R and has selective actions on epileptic hippocampal tissue. This underscores A3R as a promising target for the development of antiseizure medications. [ABSTRACT FROM AUTHOR]

Type-A γ-aminobutyric acid (GABAA) receptors are channel proteins crucial to mediating neuronal balance in the central nervous system (CNS). The structure of GABAA receptors allows for multiple binding sites and is key to drug development. Yet the formation mechanism of the receptor's distinctive pentameric structure is still unknown. This study aims to investigate the role of three predominant subunits of the human GABAA receptor in the formation of protein pentamers. Through purifying and refolding the protein fragments of the GABAA receptor α1, β2, and γ2 subunits, the particle structures were visualised with negative staining electron microscopy (EM). To aid the analysis, AlphaFold2 was used to compare the structures. Results show that α1 and β2 subunit fragments successfully formed homo-oligomers, particularly homopentameric structures, while the predominant heteropentameric GABAA receptor was also replicated through the combination of the three subunits. However, homopentameric structures were not observed with the γ2 subunit proteins. A comparison of the AlphaFold2 predictions and the previously obtained cryo-EM structures presents new insights into the subunits' modular structure and polymerization status. By performing experimental and computational studies, a deeper understanding of the complex structure of GABAA receptors is provided. Hopefully, this study can pave the way to developing novel therapeutics for neuropsychiatric diseases. [ABSTRACT FROM AUTHOR]

Understanding the molecular mechanisms underlying the generation of absence seizures is crucial for developing effective, patient-specific treatments for childhood absence epilepsy (CAE). Currently, one-third of patients remain refractive to the antiseizure medications (ASMs), previously called antiepileptic drugs (AEDs), available to treat CAE. Additionally, these ASMs often produce serious side effects and can even exacerbate symptoms in some patients. Determining the precise cellular and molecular mechanisms directly responsible for causing this type of epilepsy has proven challenging as they appear to be complex and multifactorial in patients with different genetic backgrounds. Aberrant neuronal activity in CAE may be caused by several mechanisms that are not fully understood. Thus, dissecting the causal factors that could be targeted in the development of precision medicines without side effects remains a high priority and the ultimate goal in this field of epilepsy research. The aim of this review is to highlight our current understanding of potential causative mechanisms for absence seizure generation, based on the latest research using cutting-edge technologies. This information will be important for identifying potential targets for future therapeutic intervention. [ABSTRACT FROM AUTHOR]

Background: High GABA levels and its conversion to succinate via the GABA shunt are known to be associated with abiotic and biotic stress tolerance in plants. The exact mode of action is still under debate and it is not yet clear whether GABA is a common component of the plant stress defense process or not. We hypothesized that if it is a common route for stress tolerance, activation of GABA-shunt by a biotic stressor might also function in increased abiotic stress tolerance. To test this, Brassica napus plants treated with Flagellin-22 (Flg-22) were exposed to drought stress and the differences in GABA levels along with GABA-shunt components (biosynthetic and catabolic enzyme activities) in the leaf and root samples were compared. In order to provide a better outlook, MYC2, MPK6 and ZAT12, expression profiles were also analyzed since these genes were recently proposed to function in abiotic and biotic stress tolerance. Results: Briefly, we found that Flg treatment increased drought stress tolerance in B. napus via GABA-shunt and the MAPK cascade was involved while the onset was different between leaves and roots. Flg treatment promoted GABA biosynthesis with increased GABA content and GAD activity in the leaves. Better performance of the Flg treated plants under drought stress might be dependent on the activation of GABA-shunt which provides succinate to TCA since GABA-T and SSADH activities were highly induced in the leaves and roots. In the transcript analysis, Flg + drought stressed groups had higher MYC2 transcript abundances correlated well with the GABA content and GABA-shunt while, MPK6 expression was induced only in the roots of the Flg + drought stressed groups. ZAT12 was also induced both in leaves and roots as a result of Flg-22 treatment. However, correlation with GABA and GABA-shunt could be proposed only in Flg + drought stressed group. Conclusion: We provided solid data on how GABA-shunt and Fgl-22 are interacting against abiotic stress in leaf and root tissues. Fgl-22 induced ETI activated GABA-shunt with a plausible cross talk between MYC2 and ZAT12 transcription factors for drought stress tolerance in B. napus. [ABSTRACT FROM AUTHOR]

The World Health Organization reports that 30% of adults worldwide suffer from insomnia, while 10% of people worldwide suffer with various forms of anxiety. The significant negative effects of conventional medications used to treat anxiety and insomnia, such as abuse, addiction, amnesia, and cognitive and sexual dysfunction, have led to an increased preference for naturally derived substances with fewer side effects. Accordingly, in this study, the sedative and anxiolytic effects of n-hexane, ethyl acetate (EtOAc), methanol (MeOH) and water extracts of the aerial parts of Capparis sicula Duhamel., which is used for sedative purposes in folk medicine, were evaluated. To evaluate the sedative and anxiolytic effects of each extract, bioassay systems were used including traction and hole-board tests. The MeOH extract of C. sicula was the most active extract on in vivo traction and hole-board tests compared to Diazepam. From the MeOH extract, major components were isolated, and their structures were identified as three flavonoid glycosides [rutin (1), quercetin-3-O-glucoside (2), and quercetin 3-O-rhamnoside (3)] using spectral techniques. The most abundant component was determined to be rutin, comprising 8mg/100mg dry extract in MeOH extract and 76.7 mg/100 mg dry fraction in fraction C using HPLC. The molecular docking studies evaluated the interaction of isolated flavonoid glycosides with the interaction energies and protein-ligand interaction details of the anxiety-related receptors GABAA and GABAB. For the GABAA receptor, quercetin-3-O-glucoside demonstrated the highest docking score. Quercetin-3-O-rhamnoside and rutin also show promising interactions, particularly with the GABAB receptor, highlighting their potential as modulators of these receptors. In conclusion, the use of C. sicula for sedative purposes in folk medicine has been confirmed for the first time by in vivo studies, and its possible active compounds and sedative-anxiolytic mechanism have been determined through phytochemical and in silico studies. [ABSTRACT FROM AUTHOR]

Gamma‐aminobutyric acid (GABA) is the principal inhibitory neurotransmitter in the adult brain that binds to GABA receptors and hyperpolarizes the postsynaptic neuron. Gabazine acts as a competitive antagonist to type A GABA receptors (GABAAR), thereby causing diminished neuronal hyperpolarization and GABAAR‐mediated inhibition. However, the biochemical effects and the potential regulatory role of astrocytes in this process remain poorly understood. To address this, we investigated the neuronal responses of gabazine in rat cortical cultures containing varying ratios of neurons and astrocytes. Electrophysiological characterization was performed utilizing microelectrode arrays (MEAs) with topologically controlled microcircuit cultures that enabled control of neuronal network growth. Biochemical analysis of the cultures was performed using traditional dissociated cultures on coverslips. Our study indicates that, upon gabazine stimulation, astrocyte‐rich neuronal cultures exhibit elevated electrophysiological activity and tyrosine phosphorylation of tropomyosin receptor kinase B (TrkB; receptor for brain‐derived neurotrophic factor), along with distinct cytokine secretion profiles. Notably, neurons lacking proper astrocytic support were found to experience synapse loss and decreased mitogen‐activated protein kinase (MAPK) phosphorylation. Furthermore, astrocytes contributed to neuronal viability, morphology, vascular endothelial growth factor (VEGF) secretion, and overall neuronal network functionality, highlighting the multifunctional role of astrocytes. [ABSTRACT FROM AUTHOR]

γ-Aminobutyric acid (GABA), a nonprotein amino acid, can accumulate in plants in response to abiotic stresses. The effects of postharvest treatments on endogenous GABA concentrations and exogenous GABA on whole horticulture product quality has recently received attention. However, knowledge of the effects of mechanical damage events such as peeling and cutting on GABA concentrations of fresh-cut products is limited. In this study, concentrations of GABA and antioxidants including total phenolics and ascorbic acid in fresh-cut cantaloupe, pineapple, and cauliflower during storage at 5 °C for 9 days were investigated. We found that GABA accumulated in fresh-cut pineapple and cauliflower during storage, but that the increase in cantaloupe was not significant. Total phenolics, total ascorbic acid, and dehydroascorbic acid (DHA) remained stable in fresh-cut cantaloupe and cauliflower. In pineapple, however, total phenolics and total ascorbic acid concentrations decreased, whereas the DHA concentration increased. No correlation was found between GABA and antioxidants in fresh-cut cauliflower and cantaloupe; however, GABA was negatively related to antioxidants, including total phenolics and total ascorbic acid, in fresh-cut pineapple. The results show that GABA accumulation may represent a stress response to damage that occurs during the preparation of fresh cut products, but that the degree of response is affected by the specific product. Further research of GABA metabolism in response to minimal processing, including GABA biosynthesis, in a wider range of horticultural products and relationships with antioxidants is warranted. [ABSTRACT FROM AUTHOR]

Recent studies have confirmed that pain memory is often accompanied by negative emotions. Electroacupuncture (EA) can block the retrieval of painful memories, thereby alleviating the associated negative behaviors. However, the underlying mechanism is poorly understood. This study revealed that the effect of EA on pain memory-induced negative behaviors is related to the mediation of GABAergic neuron activity and GABA receptor expression in the rostral anterior cingulate cortex (rACC). Previous studies have shown that the rACC is a crucial area for regulating nociceptive behaviors and negative emotions in pain memory models. The GABAergic neurons and receptors in the rACC are largely involved in pain sensation and related effects. However, the relationships among pain memory, GABAergic neurons and receptors in the rACC have not been investigated. In this study, we established a pain memory model via secondary plantar cross-injection of carrageenan and EA treatment. Using chemogenetic methods and behavioral assessments of pain and negative emotion, we found that early excitation of GABAergic neurons in the rACC blocked the recall of pain memories and reduced anxiety-like behaviors in pain memory model rats. Furthermore, pharmacological methods revealed that excitation of GABAA and GABAB receptors in the rACC blocks hyperpathia associated with pain memory and pain-induced anxiety-like behaviors, while inhibition of GABAA and GABAB receptors reverses these effects. These results suggest that EA may alleviate pain and associated anxiety-like behaviors related to pain memories through the activation of GABAergic neurons and excitation of GABAA and GABAB receptors in the rACC. [ABSTRACT FROM AUTHOR]

The amino acid transmitter γ-aminobutyric acid (GABA) is suspected to play an important role in regulating the activity of the gonadotropin-releasing hormone (GnRH) neurons controlling fertility. Rodent GnRH neurons have a novel dendritic compartment termed the " distal dendron " through which action potentials pass to the axon terminals and where inputs from the kisspeptin pulse generator drive pulsatile GnRH secretion. Combining Gnrh1- Cre mice with the Cre-dependent calcium sensor GCaMP6 and confocal imaging of acute brain slices, we examined whether GABA regulated intracellular calcium concentrations ([Ca2+]) in the GnRH neuron distal dendron. Short puffs of GABA on the dendron evoked either a monophasic sustained suppression of [Ca2+] or a biphasic acute elevation in [Ca2+] followed by the sustained suppression. Application of muscimol to the dendron replicated the acute elevation in [Ca2+] while baclofen generated the sustained suppression. Robust GABAB receptor-mediated inhibition was observed in 80% to 100% of dendrons recorded from females across the estrous cycle and from approximately 70% of dendrons in males. In contrast, the GABAA receptor–mediated excitation was rare in males and varied across the estrous cycle, being most prominent at proestrus. The activation of GABAB receptors potently suppressed the stimulatory effect of kisspeptin on the dendron. These observations demonstrate that the great majority of GnRH neuron distal dendrons are regulated by GABAergic inputs in a sex- and estrous cycle–dependent manner, with robust GABAB receptor-mediated inhibition being the primary mode of signaling. This provides a new, kisspeptin-independent, pathway for the regulation of pulsatile and surge modes of GnRH secretion in the rodent. [ABSTRACT FROM AUTHOR]

Rodent models may help investigations on the possible link between autism spectrum disorder and increased permeability of the gastrointestinal (GI) tract since autistic patients frequently manifested GI troubles as comorbidities.

The majority of somatosensory DRG neurons express GABAA receptors (GABAAR) and depolarise in response to its activation based on the high intracellular chloride concentration maintained by the Na-K-Cl cotransporter type 1 (NKCC1). The translation of this response to peripheral nerve terminals in people is so far unclear. We show here that GABA (EC50 = 16.67μM) acting via GABAAR produces an influx of extracellular calcium in approximately 20% (336/1720) of isolated mouse DRG neurons. In contrast, upon injection into forearm skin of healthy volunteers GABA (1mM, 100μl) did not induce any overt sensations nor a specific flare response and did not sensitize C-nociceptors to slow depolarizing electrical sinusoidal stimuli. Block of the inward chloride transporter NKCC1 by furosemide (1mg/100μl) did not reduce electrically evoked pain ratings nor did repetitive GABA stimulation in combination with an inhibited NKCC1 driven chloride replenishment by furosemide. Finally, we generated a sustained period of C-fiber firing by iontophoretically delivering codeine or histamine to induce tonic itch. Neither the intensity nor the duration of histamine or codeine itch was affected by prior injection of furosemide. We conclude that although GABA can evoke calcium transients in a proportion of isolated mouse DRG neurons, it does not induce or modify pain or itch ratings in healthy human skin even when chloride gradients are altered by inhibition of the sodium coupled NKCC1 transporter. [ABSTRACT FROM AUTHOR]

• a de novo missense mutation c.671 T > C (p.F224S) in the GABRB2 gene. • The patient bearing this mutant has epilepsy and developmental delay. • GABA A R bearing mutant β2 subunit showed decreased response to GABA. Genetic variants in genes encoding subunits of the γ-aminobutyric acid-A receptor (GABA A R) have been found to cause neurodevelopmental disorders and epileptic encephalopathy. In a patient with epilepsy and developmental delay, a de novo heterozygous missense mutation c.671 T > C (p.F224S) was discovered in the GABRB2 gene, which encodes the β2 subunit of GABA A R. Based on previous studies on GABRB2 variants, this new GABRB2 variant (F224S) would be pathogenic. To confirm and investigate the effects of this GABRB2 mutation on GABA A R channel function, we conducted transient expression experiments using GABA A R subunits in HEK293T cells. The GABA A Rs containing mutant β2 (F224S) subunit showed poor trafficking to the cell membrane, while the expression and distribution of the normal α1 and γ2 subunits were unaffected. Furthermore, the peak current amplitude of the GABA A R containing the β2 (F224S) subunit was significantly smaller compared to the wild type GABA A R. We propose that GABRB2 variant F224S is pathogenic and GABA A Rs containing this β2 mutant reduce response to GABA under physiological conditions, which could potentially disrupt the excitation/inhibition balance in the brain, leading to epilepsy. [ABSTRACT FROM AUTHOR]

Genetic epilepsy with febrile seizures plus (GEFS+) is a genetic epilepsy syndrome characterized by a marked hereditary tendency inherited as an autosomal dominant trait. Patients with GEFS+ may develop typical febrile seizures (FS), while generalized tonic–clonic seizures (GTCSs) with fever commonly occur between 3 months and 6 years of age, which is generally followed by febrile seizure plus (FS+), with or without absence seizures, focal seizures, or GTCSs. GEFS+ exhibits significant genetic heterogeneity, with polymerase chain reaction, exon sequencing, and single nucleotide polymorphism analyses all showing that the occurrence of GEFS+ is mainly related to mutations in the gamma-aminobutyric acid type A receptor gamma 2 subunit (GABRG2) gene. The most common mutations in GABRG2 are separated in large autosomal dominant families, but their pathogenesis remains unclear. The predominant types of GABRG2 mutations include missense (c.983A → T, c.245G → A, p.Met199Val), nonsense (R136*, Q390*, W429*), frameshift (c.1329delC, p.Val462fs*33, p.Pro59fs*12), point (P83S), and splice site (IVS6+2T → G) mutations. All of these mutations types can reduce the function of ion channels on the cell membrane; however, the degree and mechanism underlying these dysfunctions are different and could be linked to the main mechanism of epilepsy. The γ2 subunit plays a special role in receptor trafficking and is closely related to its structural specificity. This review focused on investigating the relationship between GEFS+ and GABRG2 mutation types in recent years, discussing novel aspects deemed to be great significance for clinically accurate diagnosis, anti-epileptic treatment strategies, and new drug development. [ABSTRACT FROM AUTHOR]

Targeted fluorescence probes for imaging and differentiation of hepatocellular carcinoma (HCC) are highly desirable from its scientific research and clinical applications. However, most of the current targeted fluorescence probes focus on the variation of intracellular microenvironment caused by the cancerization of hepatocyte, which causes a fluorescence intensity alteration but fails to produce a spatial differentiation due to the lack of robust parameters for further improving accuracy. Herein, the study develops a new fluorescent carbon dot (CTF‐CDs) that can target the overexpressed GABAA receptor (GABAAR) on cell membrane for accurate and high‐contrast imaging of HCC and differentiation. The competition response between CTF‐CDs and typical receptor‐binding ligands reveals their affinity toward the picrotoxin‐binding site of GABAAR. Based on this GABAAR‐targeting ability, accurate imaging of HCC cells is realized by lighting their membranes, along with a big difference from the intracellular fluorescence of normal liver cells and other cancer cells. In addition, the CTF‐CDs have also been used to visualize the anticancer drug‐induced variations on HCC cell membrane and fluorescent imaging in HCC tissue. This work extends the targeting object of fluorescence probes from intracellular microenvironment to membrane protein, adding a new dimension to the imaging and differentiation of HCC. [ABSTRACT FROM AUTHOR]

Background and Purpose: Transient hypofunction of the NMDA receptor represents a convergence point for the onset and further development of psychiatric disorders, including schizophrenia. Although the cumulative evidence indicates dysregulation of the hippocampal formation in schizophrenia, the integrity of the synaptic transmission and plasticity conveyed by the somatosensorial inputs to the dentate gyrus, the perforant pathway synapses, have barely been explored in this pathological condition. Experimental Approach: We identified a series of synaptic alterations of the lateral and medial perforant paths in animals postnatally treated with the NMDA antagonist MK‐801. This dysregulation suggests decreased cognitive performance, for which the dentate gyrus is critical. Key Results: We identified alterations in the synaptic properties of the lateral and medial perforant paths to the dentate gyrus synapses in slices from MK‐801‐treated animals. Altered glutamate release and decreased synaptic strength precede an impairment in the induction and expression of long‐term potentiation (LTP) and CB1 receptor‐mediated long‐term depression (LTD). Remarkably, by inhibiting the degradation of 2‐arachidonoylglycerol (2‐AG), an endogenous ligand of the CB1 receptor, we restored the LTD in animals treated with MK‐801. Additionally, we showed for the first time, that spatial discrimination, a cognitive task that requires dentate gyrus integrity, is impaired in animals exposed to transient hypofunction of NMDA receptors. Conclusion and Implications: Dysregulation of glutamatergic transmission and synaptic plasticity from the entorhinal cortex to the dentate gyrus has been demonstrated, which may explain the cellular dysregulations underlying the altered cognitive processing in the dentate gyrus associated with schizophrenia. [ABSTRACT FROM AUTHOR]

The Booroola fecunditymutation (FecB) in Small Tail Han sheep has been shown to enhance ovulation rates and litter sizes by affecting the hypothalamic-pituitary-gonadal (HPG) axis. Despite the pituitary's role in reproductive regulation, its involvement in FecB-induced ovulation remains understudied. Our study aimed to fill this gap by analyzing pituitary tissues from FecB homozygous (BB) and wildtype (WW) ewes during luteal and follicular phases using tandem mass tag-based protein quantification and the DIABLO framework for proteomic and transcriptomic data integration. Significant differences in 277 proteins were observed across estrus periods, with network analysis highlighting the voltagedependent calcium channel L-type alpha-1C as a key convergence point in oxytocin signaling and GnRH secretion pathways. The DIABLO method revealed a strong correlation (0.98) between proteomic and transcriptomic datasets, indicating a coordinated response in FecB ewes. Notably, higher expression levels of Follicle Stimulating Hormone Subunit Beta (FSHB) and Luteinizing Hormone Subunit Beta (LHB) were found in BB ewes during the follicular phase, potentially due to elevated E2 concentrations. Furthermore, our analysis identified genes related to the Gamma-aminobutyric acid type A receptor family (GABRA2, GABRG1, GABRB1) in the pituitary, with GABRB1 showing higher expression in BB ewes. This suggests a role for GABA in modulating GnRH and gonadotropin feedback loops, potentially contributing to the FecB mutation's effect on ovulation. This study provides novel insights into the pituitary's role in fertility among FecB sheep, identifying GABA as a potential regulatory factor within the HPG axis. The findings also open avenues for discovering new biomarkers in pituitary endocrinology for sheep breeding purposes. [ABSTRACT FROM AUTHOR]

In this work, the [99mTc]tricarbonyl Nefiracetam complex was labeled using the [99mTc]tricarbonyl core. Optimum conditions were implemented to achieve a radiochemical purity of 98.0% as—a substrate of 200 mg, a pH of 8, a reaction time of 30 min, and a temperature of 100°C. Biodistribution investigations of the [99mTc]tricarbonyl Nefiracetam tracer were performed on Swiss Albino mice and revealed peak brain uptake of 9.5% ID/gram in group B, Alzheimer's group at 30 min post-injection (p.i.), cleared to 1.30 ± 0.19% at 2 h post-injection. This suggests that the [99mTc]tricarbonyl Nefiracetam complex may act as a highly bio-selective tracer for brain ulcer imaging via nefiracetam induced-N-methyl-D-aspartic acid (NMDA) receptor potentiation. [ABSTRACT FROM AUTHOR]

Although classically recognized as a neurotransmitter, gamma aminobutyric acid (GABA) has also been identified in colonic tumors. Moreover, the gut microbiome represents another potential source of GABA. Both GABAA and GABAB receptors have been implicated in contributing to the effects of GABA in colorectal cancer, with both pro‐ and anti‐tumorigenic functions identified. However, their subunit composition is often overlooked. Studies to date have not addressed whether the GABA‐producing potential of the microbiome changes over the course of colon tumor development or whether receptor subunit expression patterns are altered in colon cancer. Therefore, we investigated the clusters of orthologous group frequencies of glutamate decarboxylase (GAD) in feces from two murine models of colon cancer and found that the frequency of microbial GAD was significantly decreased early in the tumorigenic process. We also determined that microbial‐derived GABA inhibited proliferation of colon cancer cells in vitro and that this effect of GABA on SW480 cells involved both GABAA and GABAB receptors. GABA also inhibited prostaglandin E2 (PGE2)‐induced proliferation and interleukin‐6 (IL‐6) expression in these cells. Gene expression correlations were assessed using the "Cancer Exploration" suite of the TIMER2.0 web tool and identified that GABA receptor subunits were differentially expressed in human colon cancer. Moreover, GABAA receptor subunits were predominantly positively associated with PGE2 synthase, cyclooxygenase‐2 and IL‐6. Collectively, these data demonstrate decreased potential of the microbiome to produce GABA during tumorigenesis, a novel anti‐tumorigenic pathway for GABA, and that GABA receptor subunit expression adds a further layer of complexity to GABAergic signaling in colon cancer. [ABSTRACT FROM AUTHOR]

Background: Catecholamines and β‐adrenergic receptors (β‐ARs) play an important role in the regulation of cardiac tolerance to the impact of ischemia and reperfusion. This systematic review analyzed the molecular mechanisms of the cardioprotective activity of β‐AR ligands. Methods: We performed an electronic search of topical articles using PubMed databases from 1966 to 2023. We cited original in vitro and in vivo studies and review articles that documented the cardioprotective properties of β‐AR agonists and antagonists. Results: The infarct‐reducing effect of β‐AR antagonists did not depend on a decrease in the heart rate. The target for β‐blockers is not only cardiomyocytes but also neutrophils. β1‐blockers (metoprolol, propranolol, timolol) and the selective β2‐AR agonist arformoterol have an infarct‐reducing effect in coronary artery occlusion (CAO) in animals. Antagonists of β1‐ and β2‐АR (metoprolol, propranolol, nadolol, carvedilol, bisoprolol, esmolol) are able to prevent reperfusion cardiac injury. All β‐AR ligands that reduced infarct size are the selective or nonselective β1‐blockers. It was hypothesized that β1‐AR blocking promotes an increase in cardiac tolerance to I/R. The activation of β1‐AR, β2‐AR, and β3‐AR can increase cardiac tolerance to I/R. The cardioprotective effect of β‐AR agonists is mediated via the activation of kinases and reactive oxygen species production. Conclusions: It is unclear why β‐blockers with the similar receptor selectivity have the infarct‐sparing effect while other β‐blockers with the same selectivity do not affect infarct size. What is the molecular mechanism of the infarct‐reducing effect of β‐blockers in reperfusion? Why did in early studies β‐blockers decrease the mortality rate in patients with acute myocardial infarction (AMI) and without reperfusion and in more recent studies β‐blockers had no effect on the mortality rate in patients with AMI and reperfusion? The creation of more effective β‐AR ligands depends on the answers to these questions. [ABSTRACT FROM AUTHOR]

The Sogatella furcifera (Horva'th) (Homoptera: Delphacidae) is a white-backed planthopper (WBPH) that causes "hopper burn" in rice, resulting in severe yield loss. Gamma-aminobutyric acid (GABA) is a well-known neurotransmitter that inhibits neurotransmission in insects by binding to specific receptors. In this study, we investigated the potential role of GABA in modulating rice resistance to WBPH and evaluated possible defense mechanisms. The experiment was conducted in green house in pots consist of four groups: control, GABAtreated, WBPH-infested, and WBPH-infested treated with GABA. Among the various tested concentration of GABA, 15 mM GABA was applied as a single treatment in water. The treatment was administered one week before WBPH infestation. The results revealed that 15 mM GABA treatment strongly increased WBPH resistance. A plate-based assay indicated that direct application of 15 mM GABA increased the mortality rate of WBPH and increased the damage recovery rate in rice plants. We found that GABA treatment increased the activation of antioxidant enzymes and reduced the reactive oxygen species content and malondialdehyde contents, and reduced the damage rate caused by WBPH. Interestingly, GABA-supplemented plants infested with WBPH exhibited increased phenylalanine ammonia-lyase and pathogenesis-related (PR) genes expression levels. GABA induced the accumulation of abscisic acid (ABA) and salicylic acid (SA) and enhanced the stomata closure and reduced leaf vessels to reduce water conductance during WBPH stress. Furthermore, we found that GABA application to the plant induced the expression of Jasmonic acid (JA) biosynthesis genes (LOX, AOS, AOC, and OPR) and melatonin biosynthesisrelated genes (TDC, T5H, ASMT, and SNAT). Our study suggested that GABA increases resistance against WBPH infestation by regulating antioxidant defense system, TCA cycle regulation, phytohormonal signaling, and PR gene regulation. [ABSTRACT FROM AUTHOR]

SUMMARY Water use efficiency (WUE) is crucial for apple tree fitness and survival, especially in response to climatic changes. The receptor‐like kinase FERONIA is reportedly an essential regulator of plant stress responses, but its role in regulating WUE under water deficit conditions is unclear. Here, we found that overexpressing the apple FERONIA receptor kinase gene, MdMRLK2, enhanced apple WUE under long‐term water deficit conditions. Under drought treatment, 35S::MdMRLK2 apple plants exhibited higher photosynthetic capacity and antioxidant enzyme activities than wild‐type (WT) plants. 35S::MdMRLK2 apple plants also showed increased biomass accumulation, root activity, and water potential compared to WT plants. Moreover, MdMRLK2 physically interacts with and phosphorylates cinnamoyl‐CoA reductase 1, MdCCR1, an enzyme essential for lignin synthesis, at position Ser260. This interaction likely contributed to increased vessel density, vascular cylinder area, and lignin content in 35S::MdMRLK2 apple plants under drought conditions. Therefore, our findings reveal a novel function of MdMRLK2 in regulating apple WUE under water deficit conditions. [ABSTRACT FROM AUTHOR]

Targeting allosteric sites of M1 muscarinic acetylcholine receptors (M1 receptors) is a promising strategy to treat neurocognitive disorders, such as Alzheimer's disease and schizophrenia. Indeed, the last two decades have seen an impressive body of work focussing on the design and development of positive allosteric modulators (PAMs) for the M1 receptor. This has led to the identification of a structurally diverse range of highly selective M1 PAMs. In preclinical models, M1 PAMs have shown rescue of cognitive deficits and improvement of endpoints predictive of symptom domains of schizophrenia. Yet, to date only a few M1 PAMs have reached early‐stage clinical trials, with many of them failing to progress further due to on‐target mediated cholinergic adverse effects that have plagued the development of this class of ligand. This review covers the recent preclinical and clinical studies in the field of M1 receptor drug discovery for the treatment of Alzheimer's disease and schizophrenia, with a specific focus on M1 PAM, highlighting both the undoubted potential but also key challenges for the successful translation of M1 PAMs from bench‐side to bedside. LINKED ARTICLES: This article is part of a themed issue Therapeutic Targeting of G Protein‐Coupled Receptors: hot topics from the Australasian Society of Clinical and Experimental Pharmacologists and Toxicologists 2021 Virtual Annual Scientific Meeting. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.14/issuetoc [ABSTRACT FROM AUTHOR]

Background: Sleep disturbances are a prevalent and complex comorbidity in neurodevelopmental disorders (NDDs). Dup15q syndrome (duplications of 15q11.2-13.1) is a genetic disorder highly penetrant for NDDs such as autism and intellectual disability and it is frequently accompanied by significant disruptions in sleep patterns. The 15q critical region harbors genes crucial for brain development, notably UBE3A and a cluster of gamma-aminobutyric acid type A receptor (GABAAR) genes. We previously described an electrophysiological biomarker of the syndrome, marked by heightened beta oscillations (12-30 Hz) in individuals with Dup15q syndrome, akin to electroencephalogram (EEG) alterations induced by allosteric modulation of GABAARs. Those with Dup15q syndrome exhibited increased beta oscillations during the awake resting state and during sleep, and they showed profoundly abnormal NREM sleep. This study aims to assess the translational validity of these EEG signatures and to delve into their neurobiological underpinnings by quantifying sleep physiology in chromosome-engineered mice with maternal (matDp/ + mice) or paternal (patDp/ + mice) inheritance of the full 15q11.2-13.1-equivalent duplication, and mice with duplication of just the UBE3A gene (Ube3a overexpression mice; Ube3a OE mice) and comparing the sleep metrics with their respective wildtype (WT) littermate controls. Methods: We collected 48-h EEG/EMG recordings from 35 (23 male, 12 female) 12–24-week-old matDp/ + , patDp/ + , Ube3a OE mice, and their WT littermate controls. We quantified baseline sleep, sleep fragmentation, spectral power dynamics during sleep states, and recovery following sleep deprivation. Within each group, distinctions between Dup15q mutant mice and WT littermate controls were evaluated using analysis of variance (ANOVA) and student's t-test. The impact of genotype and time was discerned through repeated measures ANOVA, and significance was established at p < 0.05. Results: Our study revealed that across brain states, matDp/ + mice mirrored the elevated beta oscillation phenotype observed in clinical EEGs from individuals with Dup15q syndrome. Time to sleep onset after light onset was significantly reduced in matDp/ + and Ube3a OE mice. However, NREM sleep between Dup15q mutant and WT littermate mice remained unaltered, suggesting a divergence from the clinical presentation in humans. Additionally, while increased beta oscillations persisted in matDp/ + mice after 6-h of sleep deprivation, recovery NREM sleep remained unaltered in all groups, thus suggesting that these mice exhibit resilience in the fundamental processes governing sleep-wake regulation. Conclusions: Quantification of mechanistic and translatable EEG biomarkers is essential for advancing our understanding of NDDs and their underlying pathophysiology. Our study of sleep physiology in the Dup15q mice underscores that the beta EEG biomarker has strong translational validity, thus opening the door for pre-clinical studies of putative drug targets, using the biomarker as a translational measure of drug-target engagement. The unaltered NREM sleep may be due to inherent differences in neurobiology between mice and humans. These nuanced distinctions highlight the complexity of sleep disruptions in Dup15q syndrome and emphasize the need for a comprehensive understanding that encompasses both shared and distinct features between murine models and clinical populations. [ABSTRACT FROM AUTHOR]

Voltage-gated K+ (KV) channels govern K+ ion flux across cell membranes in response to changes in membrane potential. They are formed by the assembly of four subunits, typically from the same family. Electrically silent KV channels (KVS), however, are unable to conduct currents on their own. It has been assumed that these KVS must obligatorily assemble with subunits from the KV2 family into heterotetrameric channels, thereby giving rise to currents distinct from those of homomeric KV2 channels. Herein, we show that KVS subunits indeed also modulate the activity, biophysical properties and surface expression of recombinant KV7 isoforms in a subunit-specific manner. Employing co-immunoprecipitation, and proximity labelling, we unveil the spatial coexistence of KVS and KV7 within a single protein complex. Electrophysiological experiments further indicate functional interaction and probably heterotetramer formation. Finally, single-cell transcriptomic analyses identify native cell types in which this KVS and KV7 interaction may occur. Our findings demonstrate that KV cross-family interaction is much more versatile than previously thought—possibly serving nature to shape potassium conductance to the needs of individual cell types. [ABSTRACT FROM AUTHOR]

Carbon assimilation by Rubisco is often a limitation to photosynthesis and therefore plant productivity. We have previously shown that transgenic co-expression of the Rubisco large (LS) and small (SS) subunits along with an essential Rubisco accumulation factor, Raf1, leads to faster growth, increased photosynthesis, and enhanced chilling tolerance in maize (Zea mays). Maize also requires Rubisco accumulation factor2 (Raf2) for full accumulation of Rubisco. Here we have analyzed transgenic maize lines with increased expression of Raf2 or Raf2 plus LS and SS. We show that increasing Raf2 expression alone had minor effects on photosynthesis, whereas expressing Raf2 with Rubisco subunits led to increased Rubisco content, more rapid carbon assimilation, and greater plant height, most notably in plants at least 6 weeks of age. The magnitude of the effects was similar to what was observed previously for expression of Raf1 together with Rubisco subunits. Taken together, this suggests that increasing the amount of either assembly factor with Rubisco subunits can independently enhance Rubisco abundance and some aspects of plant performance. These results could also imply either synergy or a degree of functional redundancy for Raf1 and Raf2, the latter of whose precise role in Rubisco assembly is currently unknown. [ABSTRACT FROM AUTHOR]

The development of neural circuits has long-lasting effects on brain function, yet our understanding of early circuit development in humans remains limited. Here, periodic EEG power features and aperiodic components were examined from longitudinal EEGs collected from 592 healthy 2–44 month-old infants, revealing age-dependent nonlinear changes suggestive of distinct milestones in early brain maturation. Developmental changes in periodic peaks include (1) the presence and then absence of a 9-10 Hz alpha peak between 2-6 months, (2) nonlinear changes in high beta peaks (20-30 Hz) between 4-18 months, and (3) the emergence of a low beta peak (12-20 Hz) in some infants after six months of age. We hypothesized that the emergence of the low beta peak may reflect maturation of thalamocortical network development. Infant anesthesia studies observe that GABA-modulating anesthetics do not induce thalamocortical mediated frontal alpha coherence until 10-12 months of age. Using a small cohort of infants (n = 23) with EEG before and during GABA-modulating anesthesia, we provide preliminary evidence that infants with a low beta peak have higher anesthesia-induced alpha coherence compared to those without a low beta peak. Using longitudinal EEG data from 592 infants and toddlers, the authors identify age-dependent nonlinear changes in periodic alpha and beta peaks suggestive of distinct milestones in early brain maturation, including thalamocortical network development. [ABSTRACT FROM AUTHOR]

Neuropathic pain is a type of chronic pain caused by an injury or somatosensory nervous system disease. Drugs and exercise could effectively relieve neuropathic pain, but no treatment can completely stop neuropathic pain. The integration of exercise into neuropathic pain management has attracted considerable interest in recent years, and treadmill training is the most used among exercise therapies. Neuropathic pain can be effectively treated if its mechanism is clarified. In recent years, the association between neuroinflammation and neuropathic pain has been explored. Neuroinflammation can trigger proinflammatory cytokines, activate microglia, inhibit descending pain modulatory systems, and promote the overexpression of brain-derived neurotrophic factor, which lead to the generation of neuropathic pain and hypersensitivity. Treadmill exercise can alleviate neuropathic pain mainly by regulating neuroinflammation, including inhibiting the activity of pro-inflammatory factors and over activation of microglia in the dorsal horn, regulating the expression of mu opioid receptor expression in the rostral ventromedial medulla and levels of γ-aminobutyric acid to activate the descending pain modulatory system and the overexpression of brain-derived neurotrophic factor. This article reviews and summarizes research on the effect of treadmill exercise on neuropathic pain and its role in the regulation of neuroinflammation to explore its benefits for neuropathic pain treatment. [ABSTRACT FROM AUTHOR]

Ficus benghalensis has been used by local health care practitioners to treat pain, inflammation, rheumatism, and other health issues. In this study, the crude extract and diverse fractions, along with the isolated compound of F. benghalensis were examined for their roles as muscle relaxants, analgesics, and sedatives. The extract and isolated compound 1 were screened for muscle-relaxant, analgesic, and sedative actions. The acetic acid-mediated writhing model was utilized for analgesic assessment, the muscle relaxant potential was quantified through traction and inclined plan tests, and the open field test was applied for sedative effects. The extract/fractions (25, 50, and 100 mg/kg) and isolated compounds (2.5, 5, 10, and 20 mg/kg) were tested at various doses. A profound (p< 0.001) reduce in the acetic acid-mediated writhing model was observed against carpachromene (64.44%), followed by ethyl acetate (60.67%) and methanol (58.42%) fractions. A marked (p< 0.001) muscle relaxant activity was noticed against the isolated compound (71.09%), followed by ethyl acetate (66.98%) and methanol (67.10%) fractions. Regarding the sedative effect, a significant action was noted against the isolated compound (71.09%), followed by ethyl acetate (66.98%) and methanol (67.10%) fractions. Furthermore, the binding modes of the isolated compounds were explored using molecular docking. The molecular docking study revealed that the isolated compound possessed good binding affinity for COX2 and GABA. Our isolated compound may possess inhibitory activity against COX2 and GABA receptors. The extract and isolated compounds of Ficus benghalensis can be used as analgesics, muscle relaxants, and sedatives. However, detailed molecular and functional analyses are essential to ascertain their function as muscle relaxants, analgesics, and sedatives. [ABSTRACT FROM AUTHOR]

To date, several synthetic preservatives have been used for management of food losses caused by insect and fungal pathogens, however, development of resistant races and adverse effects on environment have limited their applicability. Currently, essential oils and their bioactive components are well acknowledged for control of insects. Insecticidal and antifungal efficacy of essential oils are reported to result from neurotoxic mechanisms like alteration in octopamine receptors, γ-aminobutyric acid (GABA) ion channels, inhibition of acetylcholine esterase (AChE) activities in insects and dysfunctioning of mitochondria as well as plasma membrane in fungal pathogens. Nanoencapsulation of essential oils is currently under practice to prevent environmental degradation, enhance insecticidal and fungicidal efficacy with wide commercial applications and recommend them for possible industrial utilization. The present review explores i) insecticidal and fungicidal efficacy of essential oils and bioactive components, ii) their possible mode of action, iii) the employment of modern nanoencapsulation approaches for the development of nontoxic and ecofriendly green insecticides/fungicides, and most importantly iv) patenting of developed plant based nanoformulation with desired application in management of stored products biodeterioration. [ABSTRACT FROM AUTHOR]

Arising out of a PhD project more than 50 years ago to synthesise analogues of the neurotransmitter GABA, a series of new chemical entities were found to have selective actions on ionotropic GABA receptors. Several of these neurochemicals are now commercially available. A new subtype of these receptors was discovered that could be a target for the treatment of myopia, the facilitation of learning and memory, and the improvement of post‐stroke motor recovery. The development of these new chemical entities over many years demonstrates the importance of neurochemicals with which to investigate selective aspects of GABA receptors and illustrates the significance of collaboration between chemists and biologists in neurochemistry. Vital were the improvements in synthetic organic chemistry and the use of functional human receptors expressed in oocytes. Current interest in ionotropic GABA receptors includes the clinical development of subtype‐specific agents and the role of gain‐of‐function receptor variants in epilepsy. Dietary flavonoids were found to cross the blood–brain barrier to influence brain function. Natural and synthetic flavonoids had a range of effects on GABA receptors, ranging from positive, silent, and negative allosteric modulators, to even second‐order modulation of first‐order modulators. Flavonoids have been called "a new family of benzodiazepines." Like benzodiazepines, flavonoids reduce stress. Stress produces changes in GABA receptors in the brain that may be because of changes in endogenous modulators, such as neurosteroids and corticosteroids. GABA also occurs naturally in the diet leading to studies of the effects of oral GABA on brain function. This finding has resulted in studies of GABA and related neurochemicals as neuro‐nutraceuticals. GABA systems in the gut microbiome are essential to such studies. The actions of oral GABA and of GABA‐enriched beverages and foodstuffs are now an area of considerable scientific and commercial interest. GABA is a deceptively simple chemical that can take up many shapes, which may underlie its complex functions. The need for new chemical entities with selective actions for further studies highlights the need for continuing collaboration between chemists and biologists. [ABSTRACT FROM AUTHOR]

A significant proportion of the world's population suffers from insomnia, a disorder characterized by complications in initiating and maintaining sleep. Many medications used to treat insomnia target the γ-aminobutyric acid (GABA) neurotransmitter system. However, these substances, such as benzodiazepines, induce significant adverse consequences, including dependence and memory impairment, after prolonged use. Thus, current studies are aimed at developing therapeutic hypnotics derived from natural sources that may cause less severe side effects. Heukharang is a variety of lettuce from Korea that was discovered to contain sleep-promoting compounds. Therefore, we investigated the potential effects of sub-chronic administration of Heukharang extract (FSD-LS) on sleep behavior (pentobarbital-induced sleeping test), brain wave activity and sleep architecture (electroencephalography), and physiological behavior (open-field test and rota-rod) in mice, along with radioligand binding assays (GABAA, adenosine A1 and A2A receptors). We found that FSD-LS prolonged the total sleep duration and reduced the onset time of sleep, and enhanced delta wave power and non-rapid eye movement (NREM) sleep duration, all indicating persistent sleep-enhancing effects. FSD-LS lacked adverse effects on the spontaneous locomotor activity and motor coordination of mice, unlike diazepam. Pharmacological blocking using caffeine and bicuculline supported the possible involvement of adenosine receptors in the sleep-promoting effects of FSD-LS, with partial contribution from GABA receptor activity. Overall, our study recommends FSD-LS as a potential source for the development of sleep-aiding therapeutics. [ABSTRACT FROM AUTHOR]

The human louse (Pediculus humanus) is an obligatory blood feeding ectoparasite with two ecotypes: the human body louse (Pediculus humanus humanus), a competent vector of several bacterial pathogens, and the human head louse (Pediculus humanus capitis), responsible for pediculosis and affecting millions of people around the globe. GABA (γ-aminobutyric acid) receptors, members of the cys-loop ligand gated ion channel superfamily, are among the main pharmacological targets for insecticides. In insects, there are four subunits of GABA receptors: resistant-to-dieldrin (RDL), glycin-like receptor of drosophila (GRD), ligand-gated chloride channel homologue3 (LCCH3), and 8916 are well described and form distinct phylogenetic clades revealing orthologous relationships. Our previous studies in the human body louse confirmed that subunits Phh-RDL, Phh-GRD, and Phh-LCCH3 are well clustered in their corresponding clades. In the present work, we cloned and characterized a putative new GABA receptor subunit in the human body louse that we named HoCas, for Homologous to Cys-loop α like subunit. Extending our analysis to arthropods, HoCas was found to be conserved and clustered in a new (fifth) phylogenetic clade. Interestingly, the gene encoding this subunit is ancestral and has been lost in some insect orders. Compared to the other studied GABA receptor subunits, HoCas exhibited a relatively higher expression level in all development stages and in different tissues of human body louse. These findings improved our understanding of the complex nature of GABA receptors in Pediculus humanus and more generally in arthropods. [ABSTRACT FROM AUTHOR]

Desensitization of nicotinic acetylcholine receptors (nAChRs) can be induced by overstimulation with acetylcholine (ACh) caused by an insufficient degradation of ACh after poisoning with organophosphorus compounds (OPCs). Currently, there is no generally applicable treatment for OPC poisoning that directly targets the desensitized nAChR. The bispyridinium compound MB327, an allosteric modulator of nAChR, has been shown to act as a resensitizer of nAChRs, indicating that drugs binding directly to nAChRs can have beneficial effects after OPC poisoning. However, MB327 also acts as an inhibitor of nAChRs at higher concentrations and can thus not be used for OPC poisoning treatment. Consequently, novel, more potent resensitizers are required. To successfully design novel ligands, the knowledge of the binding site is of utmost importance. Recently, we performed in silico studies to identify a new potential binding site of MB327, MB327-PAM-1, for which a more affine ligand, UNC0646, has been described. In this work, we performed ligand-based screening approaches to identify novel analogs of UNC0646 to help further understand the structure-affinity relationship of this compound class. Furthermore, we used structure-based screenings and identified compounds representing four new chemotypes binding to MB327-PAM-1. One of these compounds, cycloguanil, is the active metabolite of the antimalaria drug proguanil and shows a higher affinity towards MB327-PAM-1 than MB327. Furthermore, cycloguanil can reestablish the muscle force in soman-inhibited rat muscles. These results can act as a starting point to develop more potent resensitizers of nAChR and to close the gap in the treatment after OPC poisoning. [Display omitted] • Identification of novel analogs of UNC0646 and new chemotypes binding to MB327-PAM-1. • Cycloguanil can reestablish rat diaphragm muscle force after soman poisoning. • Molecular dynamics simulations shed light on the binding mode of cycloguanil. [ABSTRACT FROM AUTHOR]

Background and Purpose: Neuropathic pain affects millions of patients, but there are currently few viable therapeutic options available. Microtubule affinity‐regulating kinases (MARKs) regulate the dynamics of microtubules and participate in synaptic remodelling. It is unclear whether these changes are involved in the central sensitization of neuropathic pain. This study examined the role of MARK1 or MARK2 in regulating neurosynaptic plasticity induced by neuropathic pain. Experimental Approach: A rat spinal nerve ligation (SNL) model was established to induce neuropathic pain. The role of MARKs in nociceptive regulation was assessed by genetically knocking down MARK1 or MARK2 in amygdala and systemic administration of PCC0105003, a novel small molecule MARK inhibitor. Cognitive function, anxiety‐like behaviours and motor coordination capability were also examined in SNL rats. Synaptic remodelling‐associated signalling changes were detected with electrophysiological recording, Golgi‐Cox staining, western blotting and qRT‐PCR. Key Results: MARK1 and MARK2 expression levels in amygdala and spinal dorsal horn were elevated in SNL rats. MARK1 or MARK2 knockdown in amygdala and PCC0105003 treatment partially attenuated pain‐like behaviours along with improving cognitive deficit, anxiogenic‐like behaviours and motor coordination in SNL rats. Inhibition of MARKs signalling reversed synaptic plasticity at the functional and structural levels by suppressing NR2B/GluR1 and EB3/Drebrin signalling pathways both in amygdala and spinal dorsal horn. Conclusion and Implications: These results suggest that MARKs‐mediated synaptic remodelling plays a key role in the pathogenesis of neuropathic pain and that pharmacological inhibitors of MARKs such as PCC0105003 could represent a novel therapeutic strategy for the management of neuropathic pain. [ABSTRACT FROM AUTHOR]

Marburg virus infection in humans is associated with case fatality rates that can reach up to 90%, but to date, there are no approved vaccines or monoclonal antibody (mAb) countermeasures. Here, we immunized Rhesus macaques with multivalent combinations of filovirus glycoprotein (GP) antigens belonging to Marburg, Sudan, and Ebola viruses to generate monospecific and cross-reactive antibody responses against them. From the animal that developed the highest titers of Marburg virus GP-specific neutralizing antibodies, we sorted single memory B cells using a heterologous Ravn virus GP probe and cloned and characterized a panel of 34 mAbs belonging to 28 unique lineages. Antibody specificities were assessed by overlapping pepscan and binding competition analyses, revealing that roughly a third of the lineages mapped to the conserved receptor binding region, including potent neutralizing lineages that were confirmed by negative stain electron microscopy to target this region. Additional lineages targeted a protective region on GP2, while others were found to possess cross-filovirus reactivity. Our study advances the understanding of orthomar-burgvirus glycoprotein antigenicity and furthers efforts to develop candidate antibody countermeasures against these lethal viruses. IMPORTANCE Marburg viruses were the first filoviruses characterized to emerge in humans in 1967 and cause severe hemorrhagic fever with average case fatality rates of ~50%. Although mAb countermeasures have been approved for clinical use against the related Ebola viruses, there are currently no approved countermeasures against Marburg viruses. We successfully isolated a panel of orthomarburgvirus GP-specific mAbs from a macaque immunized with a multivalent combination of filovirus antigens. Our analyses revealed that roughly half of the antibodies in the panel mapped to regions on the glycoprotein shown to protect from infection, including the host cell receptor binding domain and a protective region on the membrane-anchoring subunit. Other antibodies in the panel exhibited broad filovirus GP recognition. Our study describes the discovery of a diverse panel of cross-reactive macaque antibodies targeting orthomarburgvirus and other filovirus GPs and provides candidate immunotherapeutics for further study and development. [ABSTRACT FROM AUTHOR]

Introduction: Levilactobacillus brevis CRL 2013, a plant-derived lactic acid bacterium (LAB) with immunomodulatory properties, has emerged as an efficient producer of γ-aminobutyric acid (GABA). Notably, not all LAB possess the ability to produce GABA, highlighting the importance of specific genetic and environmental conditions for GABA synthesis. This study aimed to elucidate the intriguing GABA-producing machinery of L. brevis CRL 2013 and support its potential for safe application through comprehensive genome analysis. Methods: A comprehensive genome analysis of L. brevis CRL 2013 was performed to identify the presence of antibiotic resistance genes, virulence markers, and genes associated with the glutamate decarboxylase system, which is essential for GABA biosynthesis. Then, an optimized chemically defined culture medium (CDM) was supplemented with monosodium glutamate (MSG) and yeast extract (YE) to analyze their influence on GABA production. Proteomic and transcriptional analyses were conducted to assess changes in protein and gene expression related to GABA production. Results: The absence of antibiotic resistance genes and virulence markers in the genome of L. brevis CRL 2013 supports its safety for potential probiotic applications. Genes encoding the glutamate decarboxylase system, including two gad genes (gadA and gadB) and the glutamate antiporter gene (gadC), were identified. The gadB gene is located adjacent to gadC, while gadA resides separately on the chromosome. The transcriptional regulator gadR was found upstream of gadC, with transcriptional analyses demonstrating cotranscription of gadR with gadC. Although MSG supplementation alone did not activate GABA synthesis, the addition of YE significantly enhanced GABA production in the optimized CDM containing glutamate. Proteomic analysis revealed minimal differences between MSG-supplemented and non-supplemented CDM cultures, whereas YE supplementation resulted in significant proteomic changes, including upregulation of GadB. Transcriptional analysis confirmed increased expression of gadB and gadR upon YE supplementation, supporting its role in activating GABA production. Conclusion: These findings provide valuable insights into the influence of nutrient composition on GABA production. Furthermore, they unveil the potential of L. brevis CRL 2013 as a safe, nonpathogenic strain with valuable biotechnological traits which can be further leveraged for its probiotic potential in the food industry. [ABSTRACT FROM AUTHOR]

In this study, we investigated the effects of whey protein hydrolysate (WPH) fermented with Lactobacillus brevis on sleep behavior and GABAergic mechanisms in rodent models. Fermentation converted the glutamate in WPH to high (3.15 ± 0.21 mg/mL) levels of γ-aminobutyric acid (GABA). Fermented WPH (WP-SF) enhanced sleep duration in mice by increasing GABA content in the brain. The increase in sleep duration induced by WP-SF resulted from an increase in delta wave activity during non-rapid eye movement sleep, and its sleep-promoting effect in a caffeine-induced insomnia model was characterized by an increase in delta waves. WP-SF increased GABAergic receptors at both mRNA and protein levels. Cotreatment with GABAA receptor antagonists abolished the sleep-promoting effects of WP-SF, indicating that WP-SF shares binding sites with antagonists on GABAA receptors. Collectively, WP-SF effectively increased sleep duration by enhancing delta wave activity through GABAergic activation; thus, it is suggested as a functional food-grade ingredient for promoting sleep. [ABSTRACT FROM AUTHOR]

Glycine plays a pivotal role in the Central Nervous System (CNS), being a major inhibitory neurotransmitter as well as a co-agonist of Glutamate at excitatory NMDA receptors. Interactions involving Glycine and other neurotransmitters are the subject of different studies. Functional interactions among neurotransmitters include the modulation of release through release-regulating receptors but also through transporter-mediated mechanisms. Many transporter-mediated interactions involve the amino acid transmitters Glycine, Glutamate, and GABA. Different studies published during the last two decades investigated a number of transporter-mediated interactions in depth involving amino acid transmitters at the nerve terminal level in different CNS areas, providing details of mechanisms involved and suggesting pathophysiological significances. Here, this evidence is reviewed also considering additional recent information available in the literature, with a special (but not exclusive) focus on glycinergic neurotransmission and Glycine–Glutamate interactions. Some possible pharmacological implications, although partly speculative, are also discussed. Dysregulations in glycinergic and glutamatergic transmission are involved in relevant CNS pathologies. Pharmacological interventions on glycinergic targets (including receptors and transporters) are under study to develop novel therapies against serious CNS pathological states including pain, schizophrenia, epilepsy, and neurodegenerative diseases. Although with limitations, it is hoped to possibly contribute to a better understanding of the complex interactions between glycine-mediated neurotransmission and other major amino acid transmitters, also in view of the current interest in potential drugs acting on "glycinergic" targets. [ABSTRACT FROM AUTHOR]

Background: Tripartite motif (TRIM46) is a relatively novel protein that belongs to tripartite motif family. TRIM46 organizes parallel microtubule arrays on the axons, which are important for neuronal polarity and axonal function. TRIM46 is highly expressed in the brain, but its biological function in adults has not yet been determined. Results: Trim46 knockout (KO) rat line was established using CRISPR/cas9. Trim46 KO rats had smaller hippocampus sizes, fewer neuronal dendritic arbors and dendritic spines, and shorter and more distant axon initial segment. Furthermore, the protein interaction between endogenous TRIM46 and FK506 binding protein 5 (FKBP5) in brain tissues was determined; Trim46 KO increased hippocampal FKBP5 protein levels and decreased hippocampal protein kinase B (Akt) phosphorylation, gamma‐aminobutyric acid type A receptor subunit alpha1 (GABRA1) and glutamate ionotropic receptor NMDA type subunit 1 (NMDAR1) protein levels. Trim46 KO rats exhibited hypoactive behavioral changes such as reduced spontaneous activity, social interaction, sucrose preference, impaired prepulse inhibition (PPI), and short‐term reference memory. Conclusions: These results demonstrate the significant impact of Trim46 KO on brain structure and behavioral function. This study revealed a novel potential association of TRIM46 with dendritic development and neuropsychiatric behavior, providing new insights into the role of TRIM46 in the brain. Key Findings: The impact of Trim46 knockout on brain structure and behavioral function. [ABSTRACT FROM AUTHOR]

Summary Benzodiazepine receptor agonists are often used for insomnia in older adults contrary to current evidence. The harms outweigh the benefits, which are limited. Cognitive behavioural therapy for insomnia is the first‐line recommended treatment. Sleepwell was created as a repository of evidence‐based resources to promote cognitive behavioural therapy for insomnia and limit benzodiazepine receptor agonist use. This qualitative study uses an interpretive description design and reflexive thematic analysis to explore older adults' perspectives on behavioural change techniques used in Sleepwell resources. It also explores challenges and opportunities towards benzodiazepine receptor agonist discontinuation and cognitive behavioural therapy for insomnia use. Participants were recruited from the Sleepwell arm of a randomized controlled trial. Data were collected from 15 older adults using semi‐structured interviews. Two main themes were developed: (1) sleep should not be this difficult; and (2) whether you know it, or learn it, drugs are bad. Two sub‐themes were created within the first theme: (1) justification of benzodiazepine receptor agonist use to achieve sleep goals; (2) efforts of committing to cognitive behavioural therapy for insomnia. Several behavioural change techniques (e.g. information about consequences, anticipated regret, salience of consequences) were enablers of benzodiazepine receptor agonist‐related behaviour change. For committing to cognitive behavioural therapy for insomnia, several behavioural change techniques (e.g. self‐monitoring of behaviour, distraction, stimulus substitution) were beneficial, but social support, which was perceived as useful, was absent. Older adults experienced tension with benzodiazepine receptor agonist use and deprescribing, despite knowing or learning the potential consequences of benzodiazepine receptor agonists. Cognitive behavioural therapy for insomnia implementation was challenging. Embedded behavioural change techniques in the Sleepwell booklets were identified as helpful, but more (e.g. social support) are needed to optimize cognitive behavioural therapy for insomnia use. [ABSTRACT FROM AUTHOR]