Revisiting the role of neurotransmitters in epilepsy: An updated review

Calcium-Binding Proteins in the Autistic Brain-Potential Links to Symptom Development

Autism spectrum disorder (ASD) is a complex challenge, influenced by genetic and environmental factors. This review focuses on the proteins calbindin (CB), calretinin (CR) and parvalbumin (PV) in the context of ASD, exploring their clinical correlations and providing a deeper understanding of the spectrum. In addition, we seek to understand the role of these proteins in GABAergic regulation and their implication in the pathophysiology of ASD. The studies reviewed revealed a significant decrease in PV+ interneurons in the prefrontal cortex of individuals with ASD compared with typical controls. This reduction is associated with local synaptic hyperconnectivity, characterized by an increase in the number of excitatory synapses and a reduction in inhibitory synapses. A correlation was also observed between the decrease in PV+ and the severity of the behavioural symptoms of ASD. The research highlights GABAergic imbalance as a crucial component in the neuropathology of ASD, highlighting the role of calcium-binding proteins, especially PV, in regulating neuronal excitability and modulating synaptic connectivity. These findings provide valuable insights for the development of new therapeutic strategies intended to modulate neuronal activity and improve the symptoms associated with ASD.

Intranasal administration of antiseizure drugs using new formulation trends: one step closer to reach clinical trials

INTRODUCTION

Although there are numerous options for epilepsy treatment, its effective control continues unsatisfactory. Thus, search for alternative therapeutic options to improve the efficacy/safety binomial of drugs becomes very attractive to investigate. In this context, intranasal administration of antiseizure drugs formulated on state-of-the-art nanosystems can be a promising strategy.

AREAS COVERED

This work gives a comprehensive overview of different intranasal nanosystems for antiseizure drug administration developed and evaluated on preclinical studies over the last 10 years and published in 'PubMed' and 'Web of Science' databases. Additionally, it highlights their pharmaceutical critical quality attributes and in vivo pharmacological outputs that might infer possible results when transposing to clinical trials.

EXPERT OPINION

Research into optimized nanosystems encapsulating antiseizure drugs to enhance direct nose-to-brain delivery has increased over the last years. Particularly, the interest in formulating first- and second-generation antiseizure drugs in nanoparticles is here highlighted, having demonstrated its in vivo safety and improvement on pharmacokinetic and efficacy outputs. Still, none of them were brought to clinical trials. Thus, considering the existing barriers between preclinical and clinical trials, if supported by robust and targeted quality by design approaches, intranasal drug delivery can be presented as a valid and superior alternative for epilepsy treatment.

Genistein: A Promising Ally in Combating Neurodegenerative Disorders

Neurodegenerative disorders arise when nerve cells in the brain or peripheral nervous system gradually lose functions and eventually die. Although certain therapies may alleviate some of the physical and mental symptoms associated with neurodegenerative disorders, hence slowing their progression, but no sure-shot treatment is currently available. It was shown that the rise in life expectancy and the number of elderly people in the community led to an increasing trend in the incidence and prevalence of neurodegenerative disease. Phytomolecules are demonstrating their effectiveness in combating, regression, and delaying various diseases. Genistein is one of soy isoflavone with antioxidant, anti-inflammatory, and estrogenic effects. Researchers demonstrated that Genistein treatment significantly reduced hyperglycemia, improved cognitive performance by modulating acetylcholinesterase activity and oxidative stress, and alleviated neuroinflammatory conditions in mice. This paper evaluates (in vivo and in vitro) various molecular targets of isoflavones and their ability to effectively counter several neurodegenerative disorders such as Parkinson's, Alzheimer's, and Huntington's diseases and amyotrophic lateral sclerosis. In this review, we aim to provide an overview of the role that genistein plays in delaying the development of neurodegenerative disorders.

Mitochondrial disease and epilepsy in children

Mitochondria is the cell's powerhouse. Mitochondrial disease refers to a group of clinically heterogeneous disorders caused by dysfunction in the mitochondrial respiratory chain, often due to mutations in mitochondrial DNA (mtDNA) or nuclear DNA (nDNA) that encodes mitochondrial proteins. This dysfunction can lead to a variety of clinical phenotypes, particularly affecting organs with high energy demands, such as the brain and muscles. Epilepsy is a prevalent neurological disorder in children and is also a frequent manifestation of mitochondrial disease. The exact mechanisms underlying epilepsy in mitochondrial disease remain unclear and are thought to involve multiple contributing factors. This review explores common mitochondrial diseases associated with epilepsy, focusing on their prevalence, seizure types, EEG features, therapeutic strategies, and outcomes. It also summarizes the relationship between the molecular genetics of mitochondrial respiratory chain components and the development of epilepsy.

High-resolution multimodal profiling of human epileptic brain activity via explanted depth electrodes

The availability and integration of electrophysiological and molecular data from the living brain is critical in understanding and diagnosing complex human disease. Intracranial stereo electroencephalography (SEEG) electrodes used for identifying the seizure focus in patients with epilepsy could enable the integration of such multimodal data. Here, we report multimodal profiling of epileptic brain activity via explanted depth electrodes (MoPEDE), a method that recovers extensive protein-coding transcripts, including cell type markers, DNA methylation, and short variant profiles from explanted SEEG electrodes matched with electrophysiological and radiological data allowing for high-resolution reconstructions of brain structure and function. We found gene expression gradients that corresponded with the neurophysiology-assigned epileptogenicity index but also outlier molecular fingerprints in some electrodes, potentially indicating seizure generation or propagation zones not detected during electroclinical assessments. Additionally, we identified DNA methylation profiles indicative of transcriptionally permissive or restrictive chromatin states and SEEG-adherent differentially expressed and methylated genes not previously associated with epilepsy. Together, these findings validate that RNA profiles and genome-wide epigenetic data from explanted SEEG electrodes offer high-resolution surrogate molecular landscapes of brain activity. The MoPEDE approach has the potential to enhance diagnostic decisions and deepen our understanding of epileptogenic network processes in the human brain.

Structure-function interrelationships and associated neurotransmitter profiles in drug-naïve benign childhood epilepsy with central-temporal spikes patients

OBJECTIVES

To explore the interrelationships between structural and functional changes as well as the potential neurotransmitter profile alterations in drug-naïve benign childhood epilepsy with central-temporal spikes (BECTS) patients.

METHODS

Structural magnetic resonance imaging (sMRI) and resting-state functional MRI data from 20 drug-naïve BECTS patients and 33 healthy controls (HCs) were acquired. Parallel independent component analysis (P-ICA) was used to identify covarying components among gray matter volume (GMV) maps and fractional amplitude of low-frequency fluctuations (fALFF) maps. Furthermore, we explored the spatial correlations between GMV/fALFF changes derived from P-ICA and neurotransmitter maps in JuSpace toolbox.

RESULTS

A significantly positive correlation (p < 0.001) was identified between one structural component (GMV_IC6) and one functional component (fALFF_IC4), which showed significant group differences between drug-naïve BECTS patients and HCs (GMV_IC6: p < 0.01; fALFF_IC4: p < 0.001). GMV_IC6 showed increased GMV in the frontal lobe, temporal lobe, thalamus, and precentral gyrus as well as fALFF_IC4 had enhanced fALFF in the cerebellum in drug-naïve BECTS patients compared to HCs. Moreover, significant correlations between GMV alterations in GMV_IC6 and the serotonin (5HT1a: p < 0.001; 5HT2a: p < 0.001), norepinephrine (NAT: p < 0.001) and glutamate systems (mGluR5: p < 0.001) as well as between fALFF alterations in fALFF_IC4 and the norepinephrine system (NAT: p < 0.001) were detected.

CONCLUSION

The current findings suggest co-altered structural/functional components that reflect the correlation of language and motor networks as well as associated with the serotonergic, noradrenergic, and glutamatergic neurotransmitter systems.

CLINICAL RELEVANCE STATEMENT

The relationship between anatomical brain structure and intrinsic neural activity was evaluated using a multimodal fusion analysis and neurotransmitters which might provide an important window into the multimodal neural and underlying molecular mechanisms of benign childhood epilepsy with central-temporal spikes.

KEY POINTS

Structure-function relationships in drug-naïve benign childhood epilepsy with central-temporal spikes (BECTS) patients were explored. The interrelated structure-function components were found and correlated with the serotonin, norepinephrine, and glutamate systems. Co-altered structural/functional components reflect the correlation of language and motor networks and correlate with the specific neurotransmitter systems.

Assessment of Neurotoxic Mechanisms of Individual and Binary Mixtures of Cobalt, Nickel and Lead in Hippocampal Neuronal Cells

Many studies have focused on the neurotoxic effects of single metals, while investigation on the exposure to metal mixtures, which mainly occur in real-life situations, is scarce. This study sought to assess the neurotoxic effect of Ni, Co, and Pb binary mixtures and their individual effects in hippocampal neuronal cells (HT-22). Cells were exposed to Ni, Co, and Pb separately for 48 h at 37°C and 5% CO2, and cell viability was assessed. Morphological assessment of the cells exposed to binary mixtures of Co, Ni, and Pb and single metals was assessed using a microscope. Furthermore, acetylcholinesterase (AChE) activity, oxidative stress biomarkers (glutathione [GSH] and malondialdehyde [MDA] levels, catalase [CAT], and glutathione-S transferase [GST] activities) and nitric oxide [NO] levels were evaluated after treatment with the binary mixtures and single metals. Binary mixtures of the metals reduced cell viability, exerting an additivity action. The combinations also exerted synergistic action, as revealed by the combination index. Furthermore, a significant reduction in AChE activity, GSH levels, CAT and GST activities, and high MDA and NO levels were observed in neuronal cells. The additive interactions and synergistic actions of the binary mixtures might contribute to the significant reduction of AChE activity, GSH levels, GST, and CAT activities, and an increase in MDA and NO levels. The findings from this study revealed significant evidence that binary mixtures of Co, Pb, and Ni may induce impaired neuronal function and, ultimately, neurodegeneration.

Epilepsy Treatment and Diagnosis Enhanced by Current Nanomaterial Innovations: A Comprehensive Review

Epilepsy is a complex disease in the brain. Complete control of seizure has always been a challenge in epilepsy treatment. Currently, clinical management primarily involves pharmacological and surgical interventions, with the former being the preferred approach. However, antiepileptic drugs often exhibit low bioavailability due to inherent limitations such as poor water solubility and difficulty penetrating the blood-brain barrier (BBB). These issues significantly reduce the drugs' effectiveness and limit their clinical application in epilepsy treatment. Additionally, the diagnostic accuracy of current imaging techniques and electroencephalography (EEG) for epilepsy is suboptimal, often failing to precisely localize epileptogenic tissues. Accurate diagnosis is critical for the surgical management of epilepsy. Thus, there is a pressing need to enhance both the therapeutic outcomes of epilepsy medications and the diagnostic precision of the condition. In recent years, the advancement of nanotechnology in the biomedical sector has led to the development of nanomaterials as drug carriers. These materials are designed to improve drug bioavailability and targeting by leveraging their large specific surface area, facile surface modification, ability to cross the BBB, and high biocompatibility. Furthermore, nanomaterials have been utilized as contrast agents in imaging and as materials for EEG electrodes, enhancing the accuracy of epilepsy diagnoses. This review provides a comprehensive examination of current research on nanomaterials in the treatment and diagnosis of epilepsy, offering new strategies and directions for future investigation.

Therapeutic potential of the extract of giant millipede Telodeinopus Canaliculatus on epileptogenesis and associated anxiety-like behavior

The secretions of Telodeinopus canaliculatus, a giant millipede, are used in traditional medicine to treat epileptic seizures. Therefore, this work aimed to assess the antiepileptogenic- and anxiolytic-like effects of an extract of T. canaliculatu in mice. Forty-eight mice were divided into six groups of eight each and treated as follows: normal control group received distilled water (10 ml/kg, p.o.); negative control group received received distilled water (10 ml/kg, p.o.); positive control group received sodium valproate (300 mg/kg, p.o.); and test groups received with the extract (30, 50, and 70 mg/kg, p.o.). One hour later, all groups, except the normal control group (distilled water, 10 ml/kg, i.p.), received a daily dose of pentylenetetrazole (25 mg/kg, i.p) until the onset of tonic-clonic seizures on day 24. On day 26 of the experiment, anxious behaviors were assessed. The mice were subsequently sacrificed and brains were collected for neurochemical analyses. The extract (30, 50, 70 mg/kg, p.o.) reduced (p < 0.001) the seizure severity. It also increased the latencies to the onset of seizures. In the elevated plus maze, the extract (50 mg/kg) increased by 51% (p < 0.001) the time spent in the open arms. The extract (50 mg/kg) increased GABA concentration by 28% (p < 0.01) and 37% (p < 0.001) respectively in the hippocampus and amygdala. Moreover, the extract (30 mg/kg) decreased the concentration of malondialdehyde by 47% (p < 0.001) and 42% (p < 0.01) respectively in the same regions. The hydroethanolic extract of T. canaliculatus is endowed with antiepileptogenic and anxiolytic effects.

The effect of acetylcholinesterase inhibitor rivastigmine in pentylenetetrazole-induced kindling model of epilepsy in rats

This study aimed to investigate the role of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitor rivastigmine (RIVA) in the pentylenetetrazole (PTZ)- induced kindling model of epilepsy. The current study consists of three steps; 1) Saline or RIVA (0.5, 1, and 2 mg/kg) was administered intraperitoneally (i.p.) 15 min before PTZ (35 mg/kg) during the kindling process and seizure behaviors were observed; 2) Single doses of RIVA (0.25, 0.5, and 1 mg/kg; i.p.) was administered to the electrode implanted kindled rats 15 min before PTZ and electrocorticogram (ECoG) recordings were obtained; 3) Low-dose of RIVA (0.5 mg/kg) was administered to the kindled rats for 14 consecutive days and after 24 h PTZ was administered and ECoG recordings were obtained. In addition, 24 h after the PTZ injection, the hippocampus was extracted and mRNA expression levels of N-methyl D-aspartate receptor subunit 2B (NR2B) and brain-derived neurotrophic factor (BDNF) were measured by qPCR analysis. Only low-dose of RIVA increased resistance against kindling. Single and long-term administration of low-dose RIVA increased the latency to the first myoclonic jerk, decreased the duration of generalized tonic-clonic seizures, and reduced the seizure stage in kindled rats. Long-term low-dose RIVA treatment decreased the mRNA expressions of NR2B and BDNF, which were increased after PTZ kindling. Low-dose of RIVA showed anticonvulsant properties, while high doses did not. RIVA exerts its anticonvulsant effect probably through NMDAR-BDNF pathways. Our results suggest that the use of RIVA may not be harmful and even reduce seizure severity in epileptic patients with convulsions.

The Oxidative Stress in Epilepsy-Focus on Melatonin

Oxidative stress develops when there is an excess of oxidants leading to molecular and cellular damage. Seizure activity leads to oxidative stress and the resulting increased lipid peroxidation. Generally, antiseizure medications reduce oxidative stress, although the data on levetiracetam are ambiguous. Exogenous antioxidants (vitamin E, resveratrol, hesperidin, and curcumin) have been documented to exert an anticonvulsant effect in animal models of seizures and some recent clinical data point to curcumin as an affective adjuvant for the therapy of pediatric intractable epilepsy. Melatonin is an antioxidant with an ability to attenuate seizure activity induced by various convulsants in rodents. Its clinical effectiveness has been also confirmed in a number of clinical studies. Experimental studies point to a possibility that endogenous melatonin may possess proconvulsive activity. Moreover, some scarce clinical data seem to express this view; however, a limited number of patients were included. The anticonvulsant activity of exogenous melatonin may involve GABA-mediated inhibition, while endogenous melatonin may act as a proconvulsant due to a decrease in the brain dopaminergic transmission. Antioxidants, including melatonin, may be considered as adjuvants in the therapy of epilepsy and melatonin, in addition, in patients with epilepsy suffering from sleep disorders.

The JNK Signaling Pathway Regulates Seizures Through ENT1 in Pilocarpine-Induced Epilepsy Rat Model

OBJECTIVE

The study investigates whether the expression and function of ENT1 can be regulated by inhibiting the JNK signaling pathway, thereby altering the levels of extracellular adenosine and glutamate in neurons, and subsequently affecting the progression of epilepsy.

METHODS

The adult male SD rats were randomly divided into four groups: EP + SP600125 group, EP + DMSO group, EP group, and normal control group. The expression levels of ENT1, p-JNK, and JNK in the hippocampus of rats from each experimental group were detected using Western blotting technology. The expression and localization of ENT1 and p-JNK in the CA1, CA3, and DG areas of the hippocampus were detected by immunohistochemical staining and immunofluorescence staining. Microdialysis combined with liquid chromatography-mass spectrometry was used to determine the concentrations of adenosine and glutamate in the extracellular fluid of hippocampus in each experimental group.

RESULTS

This study showed that the JNK-specific inhibitor SP600125 could reduce ENT1 expression and seizure intensity in experimental rats. Statistical analysis confirmed that adenosine and glutamate levels in the extracellular fluid of the hippocampus increased significantly after seizures in rats, and the JNK-specific inhibitor SP600125 could increase adenosine levels in the extracellular fluid but decrease glutamate levels.

SIGNIFICANCE

The JNK-specific inhibitor SP600125 can specifically inhibit the JNK signaling pathway and reduce the expression of ENT1 transporter. The mechanism is related to the transport of adenosine from the extracellular space to the intracellular space by ENT1 during epileptic states. Inhibition of ENT1 can increase the concentration of adenosine in the extracellular fluid of the hippocampus. The increase in adenosine concentration stopped glutamate from being released and reduced the amount of glutamate in the outside of the cell.

High Translocation of High Mobility Group Box 1 in the Brain Tissue of Patients with Sturge-Weber Syndrome

Purpose

Sturge-Weber syndrome (SWS), a rare congenital neurological and skin disorder, is frequently associated with drug-resistant epilepsy. Translocation of high mobility group box 1 (HMGB1) protein from the nucleus to the cytoplasm or extracellular milieu has been implicated in neuroinflammatory processes contributing to the development of epileptogenesis. This study aimed to explore the expression and distribution of HMGB1 in brain tissue from SWS patients with drug-resistant epilepsy, with the goal of elucidating its potential involvement in the pathogenesis of epilepsy.

Patients and Methods

The study enrolled eight patients with drug-resistant epilepsy who underwent hemispherectomy. Brain tissue specimens were obtained and analyzed using immunofluorescence staining to detect HMGB1 distribution in microglia, astrocytes, or different neuronal subtypes. Correlation analyses were performed to investigate the potential relationship between HMGB1 translocation within cells and the clinical characteristics of SWS patients.

Results

In lesional tissues of SWS patients, we observed significantly higher cytoplasmic HMGB1 levels. Meanwhile, HMGB1 was widely distributed in the cytoplasm of microglia and neurons, while in astrocytes, it was primarily localized in the nucleus. This translocation occurred across many neuronal subtypes, including excitatory glutamatergic, inhibitory GABAergic, and cholinergic neurons. The lower proportion of HMGB1-translocated cholinergic neurons was seen compared to the other two neuronal subtypes. Furthermore, no correlation was found between cytoplasmic HMGB1 levels and clinical characteristics of SWS patients.

Conclusion

The results suggest the involvement of HMGB1 in the pathogenesis of drug-resistant epilepsy in SWS patients. Additional research is required to elucidate the precise mechanisms and potential therapeutic targets associated with HMGB1 that underlie the epilepsy linked to SWS.

Revealing the optimal traditional processing methods and its protective effects against febrile seizures of Arisaema cum bile

Arisaema cum bile (known as Dan Nanxing in Chinese, DNX) is a herbal medicine used for treating febrile seizure (FS), which commonly prepared by using Arisaematis Rhizoma and animal bile. This study was designed to explore the optimal processing time of DNX and its potential mechanism on the anti-FS effect. A total of 17 volatile organic compounds (VOCs) were the characteristic ones to distinguish different fermentation stages of DNX by using gas chromatography-ion mobility spectrometry (GC-IMS), such as 2-heptanone monomer, and heptanal monomer. DNX with fermentation for 3 months had an obvious pattern of VOCs with others, which could be regarded as the optimal fermentation time. The Enterococcus and Staphylococcus might be the core bacteria on the production of VOCs. Additionally, DNX (2.8 g/kg, p.o.) reversed hot water bath-induced FSs of rats, as indicated by increased seizure latency and decreased seizure duration time. It also prevented hippocampal neuronal loss, increased GABAAR, and decreased GRIA1 expression. At the genus level, relative abundance of Enterococcus and Akkermansia were enriched after DNX treatment. These findings suggested that fermentation for 3 months might be the optimal process time for DNX, and DNX possess an anti-FS effect through regulating neurotransmitter disorder and gut microbiota.

Behavioral dysregulation in Nile tilapia (Oreochromis niloticus, GIFT) post-Streptococcus agalactia infection: Role of the microbiota-gut-brain axis

In the aquatic farming industry, understanding the factors affecting fish behavior is crucial, particularly in response to infections that compromise welfare and productivity. Swimming performance is a key life history trait critical to their ecology. This study explores the swimming behavior imbalance in Nile tilapia (Oreochromis niloticus, GIFT) post-infection with Streptococcus agalactiae (GBS), a common pathogen responsible for significant losses in aquaculture. We focused on how the microbiota-gut-brain axis influences the behavioral response of tilapia to GBS infection. Behavioral changes were quantified by measuring collision times and swimming speeds, which decreased significantly following infection. This behavioral downturn is mediated by alterations in the microbiota-gut-brain axis, evidenced by increased levels of monoamine neurotransmitters (serotonin, norepinephrine, and dopamine) in the brain and intestinal tissues. The study utilized pharmacological agents, the 5-HT1A receptor agonist (8-OH-DPAT) and antagonist (WAY-100635), to investigate their efficacy in mitigating these behavioral and biochemical changes. Both agents partially restored normal behavior by adjusting neurotransmitter concentrations disrupted by GBS infection. Additionally, a notable increase in the relative abundance of Streptococcus within the gut microbiota of infected fish highlights the potential role of specific bacterial populations in influencing host behavior. This research provides novel insights into the complex interactions between pathogen-induced gut microbiota changes and Nile tilapia's behavioral outcomes, highlighting potential avenues for improving fish health management through microbiota-targeted interventions.

YTHDF1 gene inhibits epilepsy progression by epigenetic activation of PTEN gene

Epilepsy is a common chronic neurological disorder with high prevalence that profoundly affects millions of people worldwide. Inflammatory dysregulation affects central nervous system disorders including epilepsy, and YTHDF1, the most common "reader" of m6A and m6A-binding protein, can attenuate the inflammatory response and activate PTEN, and here we aimed to investigate its effect on epilepsy through epigenetics. All mice were injected intraperitoneally with 12 mg/kg of sea manic acid to establish an epilepsy model, and the epileptic behaviors of the mice were classified into 6 grades; epileptic behaviors of grade 3 or above were defined as seizures, and consecutive epileptic seizures of more than 30 min were considered as successful modeling. Mouse behavior was examined using the Morris Water Maze tracking assay; inflammatory factors IL-6, TNF-α, and IL-1β were detected by qPCR/WB/ELISA; cell activity was analyzed by CCK-8; apoptotic markers were identified by immunofluorescence assay and Western blot analysis. YTHDF1 knockout mice have poor spatial memory capacity and sensitivity to external stimuli. Under the influence of YTHDF1, the neuroinflammation and nseuron death decreased. YTHDF1 works by repressing the production of pro-inflammatory cytokines and the activation of astrocytes. It was found that YTHDF1 epigenetically activates PTEN through m6A modification, activates glial cells and represses pro-inflammatory cytokines production and inhibits the development of epilepsy.

Unveiling the multifaceted pathogenesis and therapeutic drugs of Alzheimer's disease: A comprehensive review

Alzheimer's disease (AD) is a severe neurodegenerative disorder characterized by the accumulation of β-amyloid (Aβ) plaques and tau phosphorylation-induced neurofibrillary tangles. This review comprehensively summarizes AD pathogenesis and related factors, drawing on a wealth of authoritative reports and research findings. Specifically, we delve into the intricate mechanisms underlying AD pathology, including Aβ deposition, tau protein phosphorylation, cholinergic dysfunction, neuroinflammation, mitochondrial oxidative stress, ferroptosis, imbalance in the gut microbiota, and microRNA dysregulation. We also explored the effects of these factors on the brain, including synaptic damage and cognitive impairment. Moreover, our review highlights the associations between the pathogenesis of AD and inflammatory cytokines in the peripheral blood and cerebrospinal fluid, dysbiosis of the gut microbiota, and changes in microRNA expression. Overall, we provided a systematic and illustrative overview of the pathogenesis and therapeutic drugs for AD, offering help in the prevention and treatment of this condition.

Aging of Krushinsky-Molodkina audiogenic rats is accompanied with pronounced neurodegeneration and dysfunction of the glutamatergic system in the hippocampus

Advancing age strongly correlates with an increased risk of epilepsy development. On the other hand, epilepsy may exacerbate the negative effects of aging making it pathological. In turn, the possible link between aging and epileptogenesis is dysregulation of glutamatergic transmission. In the present study, we analyzed the functional state of the glutamatergic system in the hippocampus of aging (18-month-old) Krushinsky-Molodkina (KM) audiogenic rats to disclose alterations associated with aging on the background of inherited predisposition to audiogenic seizures (AGS). Naïve KM rats with no AGS experience were recruited in the experiments. Wistar rats of the corresponding age were used as a control. First of all, aging KM rats demonstrated a significant decrease in cell population and synaptopodin expression in the hippocampus indicating enhanced loss of cells and synapses. Meanwhile, elevated phosphorylation of ERK1/2 and CREB and increased glutamate in the neuronal perikarya were revealed indicating increased activity of the rest hippocampal cells and increased glutamate production. However, glutamate in the fibers and synapses was mainly unchanged, and the proteins regulating glutamate exocytosis showed variable changes which could compensate each other and maintain glutamate release at the unchanged level. In addition, we revealed downregulation of NMDA-receptor subunit GluN2B and upregulation of AMPA-receptor GluA2 subunit, which could also prevent overexcitation and support cell survival in the hippocampus of aging KM rats. Nevertheless, abnormally high glutamate production, observed in aging KM rats, may provide the basis for hyperexcitability of the hippocampus and increased seizure susceptibility in old age.

Differential involvement of central and peripheral catecholamines between Alzheimer's disease and vascular dementia

Background and aim

The important role of catecholamines has been gradually emphasized in the pathogenesis of neurodegenerative process. As the most prevalent form of cognitive dysfunction, Alzheimer's disease (AD) and vascular dementia (VaD) have the distinct pathological features and pathogenic mechanisms, however, the differential involvement of central and peripheral catecholamines between AD and VaD was still unclear.

Methods

Triple-transgenic AD (3 × Tg-AD) mice and chronic cerebral hypoperfusion (CCH) in rats induced by two-vessel occlusion (2VO) were used as the AD and VaD model in this study, respectively. The concentrations of catecholamines (dopamine, epinephrine and norepinephrine) and their metabolites (3-methoxytyramine, metanephrine and normetanephrine) in serum and five brain regions (hippocampus, cortex, corpus striatum, thalamus and pons) from 3 × Tg-AD mice and 2VO rats were quantitatively determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay.

Results

High expression and distribution of hippocampal dopamine, and epinephrine and norepinephrine in the cortex and thalamus were found in the early 3 × Tg-AD model, whereas chronic cerebral hypoperfusion induced by 2VO mainly affected the central noradrenergic and noradrenergic system, but not dopaminergic system. The increased serum levels of catecholamines were investigated in the 2VO rats, but not in the 3 × Tg-AD mice.

Conclusion

The differential expression and distribution of central catecholamines and their metabolites suggests the distinct catecholamines-related pathogenesis between AD and VaD. Peripheral catecholamine surge may be involved in the development of VaD, and the treatment strategy to prevent or reverse the effects of peripheral catecholamines may be protective for VaD.

Identification of metabolomic changes and potential therapeutic targets during ovarian aging

PURPOSE

To reveal the metabolic differences of follicle fluid (FF) and granulosa cell (GC) between younger women and advanced age women in ART cycles, and then find potential therapeutic targets of ovarian aging.

METHODS

Forty-five patients were included in the study and they were divided into three groups according to their age (Group A: 20-30 years old; Group B: 30-35 years old; Group C: 35-45 years old). All patients underwent controlled ovarian stimulation using the follicular phase long-acting protocol, FF and GC were obtained 36-38 hours after HCG administration. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used for metabolomics analysis and metabolic pathway analysis (MetPA) was utilized to find related pathways.

RESULTS

Between group A and group C, there were 72 and 21 differential metabolites in FF and GC, respectively. KEGG enrichment analysis showed six pathways were co-enriched by the differential metabolites of FF and GC. Among them, we noticed that in the pathway GABAergic synapse, GABA (gamma-aminobutyric acid) was down-regulated in GC, while its downstream metabolite succinic acid was down-regulated in FF. Further ROC curve analysis was performed on these two metabolites, and the results showed that they all had a favorable predictive value.

CONCLUSION

This study indicated that GABA and succinic acid could be potential therapeutic targets for ovarian aging, GABA may delay ovarian aging and improve ovarian function through its antioxidant properties, which may be a future direction of clinical treatment.

Alterations in DNA 5-hydroxymethylation patterns in the hippocampus of an experimental model of chronic epilepsy

Temporal lobe epilepsy (TLE) is a type of focal epilepsy characterized by spontaneous recurrent seizures originating from the hippocampus. The epigenetic reprogramming hypothesis of epileptogenesis suggests that the development of TLE is associated with alterations in gene transcription changes resulting in a hyperexcitable network in TLE. DNA 5-methylcytosine (5-mC) is an epigenetic mechanism that has been associated with chronic epilepsy. However, the contribution of 5-hydroxymethylcytosine (5-hmC), a product of 5-mC demethylation by the Ten-Eleven Translocation (TET) family proteins in chronic TLE is poorly understood. 5-hmC is abundant in the brain and acts as a stable epigenetic mark altering gene expression through several mechanisms. Here, we found that the levels of bulk DNA 5-hmC but not 5-mC were significantly reduced in the hippocampus of human TLE patients and in the kainic acid (KA) TLE rat model. Using 5-hmC hMeDIP-sequencing, we characterized 5-hmC distribution across the genome and found bidirectional regulation of 5-hmC at intergenic regions within gene bodies. We found that hypohydroxymethylated 5-hmC intergenic regions were associated with several epilepsy-related genes, including Gal, SV2, and Kcnj11 and hyperdroxymethylation 5-hmC intergenic regions were associated with Gad65, TLR4, and Bdnf gene expression. Mechanistically, Tet1 knockdown in the hippocampus was sufficient to decrease 5-hmC levels and increase seizure susceptibility following KA administration. In contrast, Tet1 overexpression in the hippocampus resulted in increased 5-hmC levels associated with improved seizure resiliency in response to KA. These findings suggest an important role for 5-hmC as an epigenetic regulator of epilepsy that can be manipulated to influence seizure outcomes.

Zebrafish models of human-duplicated SRGAP2 reveal novel functions in microglia and visual system development

The expansion of the human SRGAP2 family, resulting in a human-specific paralog SRGAP2C, likely contributed to altered evolutionary brain features. The introduction of SRGAP2C in mouse models is associated with changes in cortical neuronal migration, axon guidance, synaptogenesis, and sensory-task performance. Truncated SRGAP2C heterodimerizes with the full-length ancestral gene product SRGAP2A and antagonizes its functions. However, the significance of SRGAP2 duplication beyond neocortex development has not been elucidated due to the embryonic lethality of complete Srgap2 knockout in mice. Using zebrafish, we show that srgap2 knockout results in viable offspring and that these larvae phenocopy "humanized" SRGAP2C larvae, including altered morphometric features (i.e., reduced body length and inter-eye distance) and differential expression of synapse-, axonogenesis-, and vision-related genes. Through single-cell transcriptome analysis, we demonstrate a skewed balance of excitatory and inhibitory neurons that likely contribute to increased susceptibility to seizures displayed by Srgap2 mutant larvae, a phenotype resembling SRGAP2 loss-of-function in a child with early infantile epileptic encephalopathy. Single-cell data also shows strong endogenous expression of srgap2 in microglia with mutants exhibiting altered membrane dynamics and likely delayed maturation of microglial cells. Microglia cells expressing srgap2 were also detected in the developing eye together with altered expression of genes related to axonogenesis in mutant retinal cells. Consistent with the perturbed gene expression in the retina, we found that SRGAP2 mutant larvae exhibited increased sensitivity to broad and fine visual cues. Finally, comparing the transcriptomes of relevant cell types between human (+SRGAP2C) and non-human primates (-SRGAP2C) revealed significant overlaps of gene alterations with mutant cells in our zebrafish models; this suggests that SRGAP2C plays a similar role altering microglia and the visual system in modern humans. Together, our functional characterization of conserved ortholog Srgap2 and human SRGAP2C in zebrafish uncovered novel gene functions and highlights the strength of cross-species analysis in understanding the development of human-specific features.

Recent developments in delirium after oral and maxillofacial free-flap reconstruction

Postoperative delirium (POD), a common complication following surgery and anesthesia, is particularly prone to occur after reconstruction surgery in the oral and maxillofacial region. The occurrence of POD seriously affects the incidence of postoperative complications, the survival of free flaps, the length of hospital stays, and brings great pain to patients and their families, and even increases perioperative mortality. Currently, a large number of studies have reported on the risk factors for POD after oral and maxillofacial free-flap reconstruction. Multiple independent risk factors have been identified, including age, history of excessive alcohol consumption, and perioperative nutritional status. This review summarizes the relevant literature and hopes to provide insights for the prevention of POD in high-risk patients.

Decoding the Gut Microbiome in Companion Animals: Impacts and Innovations

The changing notion of "companion animals" and their increasing global status as family members underscores the dynamic interaction between gut microbiota and host health. This review provides a comprehensive understanding of the intricate microbial ecology within companion animals required to maintain overall health and prevent disease. Exploration of specific diseases and syndromes linked to gut microbiome alterations (dysbiosis), such as inflammatory bowel disease, obesity, and neurological conditions like epilepsy, are highlighted. In addition, this review provides an analysis of the various factors that impact the abundance of the gut microbiome like age, breed, habitual diet, and microbe-targeted interventions, such as probiotics. Detection methods including PCR-based algorithms, fluorescence in situ hybridisation, and 16S rRNA gene sequencing are reviewed, along with their limitations and the need for future advancements. Prospects for longitudinal investigations, functional dynamics exploration, and accurate identification of microbial signatures associated with specific health problems offer promising directions for future research. In summary, it is an attempt to provide a deeper insight into the orchestration of multiple microbial species shaping the health of companion animals and possible species-specific differences.

Development of a novel glucose-dendrimer based therapeutic targeting hyperexcitable neurons in neurological disorders

Neuronal hyperexcitability and excitotoxicity lies at the core of debilitating brain disorders such as epilepsy and traumatic brain injury, culminating in neuronal death and compromised brain function. Overcoming this challenge requires a unique approach that selectively restores normal neuronal activity and rescues neurons from impending damage. However, delivering drugs selectively to hyperexcitable neurons has been a challenge, even upon local administration. Here, we demonstrate the remarkable ability of a novel, scalable, generation-two glucose-dendrimer (GD2) made primarily of glucose and ethylene glycol building blocks, to specifically target hyperexcitable neurons in primary culture, ex vivo acute brain slices, and in vivo mouse models of acute seizures. Pharmacology experiments in ex vivo brain slices suggest GD2 uptake in neurons is mediated through glucose transporters (GLUT and SGLT). Inspired by these findings, we conjugated GD2 with a potent anti-epileptic drug, valproic acid (GD2-VPA), for efficacy studies in the pilocarpine-mouse model of seizure. When delivered intranasally, GD2-VPA significantly decreased the seizure-severity. In summary, our findings demonstrate the unique selectivity of glucose dendrimers in targeting hyperexcitable neurons, even upon intranasal delivery, laying the foundation for neuron-specific therapies for the precise protection and restoration of neuronal function, for targeted neuroprotection.

MicroRNA-mediated regulation of neurotransmitter receptors in epilepsy: A systematic review

BACKGROUND

Pathogenesis of epilepsy involves dysregulation of the neurotransmitter system contributing to hyper-excitability of neuronal cells. MicroRNA (miRNAs) are small non-coding RNAs known to play a crucial role in post-transcriptional regulation of gene expression.

METHODS

The present review was prepared following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, employing a comprehensive search strategy to identify and extract data from published research articles. Keywords suchas epilepsy, micro RNA (micro RNAs, miRNA, miRNAs, miR), neurotransmitters (specific names), and neurotransmitter receptors (specific names) were used to construct the query.

RESULTS

A total of 724 articles were identified using the keywords epilepsy, microRNA along with select neurotransmitter and neurotransmitter receptor names. After exclusions, the final selection consisted of 17 studies, most of which centered on glutamate and gamma-aminobutyric acid (GABA) receptors. Singular studies also investigated miRNAs affecting cholinergic, purinergic, and glycine receptors.

CONCLUSION

This review offers a concise overview of the current knowledge on miRNA-mediated regulation of neurotransmitter receptors in epilepsy and highlights their potential for future clinical application.

TRPV1 channel in the pathophysiology of epilepsy and its potential as a molecular target for the development of new antiseizure drug candidates

Identification of transient receptor potential cation channel, subfamily V member 1 (TRPV1), also known as capsaicin receptor, in 1997 was a milestone achievement in the research on temperature sensation and pain signalling. Very soon after it became evident that TRPV1 is implicated in a wide array of physiological processes in different peripheral tissues, as well as in the central nervous system, and thereby could be involved in the pathophysiology of numerous diseases. Increasing evidence suggests that modulation of TRPV1 may also affect seizure susceptibility and epilepsy. This channel is localized in brain regions associated with seizures and epilepsy, and its overexpression was found both in animal models of seizures and in brain samples from epileptic patients. Moreover, modulation of TRPV1 on non-neuronal cells (microglia, astrocytes, and/or peripheral immune cells) may have an impact on the neuroinflammatory processes that play a role in epilepsy and epileptogenesis. In this paper, we provide a comprehensive and critical overview of currently available data on TRPV1 as a possible molecular target for epilepsy management, trying to identify research gaps and future directions. Overall, several converging lines of evidence implicate TRPV1 channel as a potentially attractive target in epilepsy research but more studies are needed to exploit the possible role of TRPV1 in seizures/epilepsy and to evaluate the value of TRPV1 ligands as candidates for new antiseizure drugs.

Selective and Comparative Study of B/nZVCu-Fe and B/nZVCu-Zn Nanoparticles as Fluorescent Probe for Dopamine in Presence of its Interference Molecules

This work focuses on the synthesis of Bentonite supported nano zero valent bimetallic nanoparticles (B/nZVCu-M NPs) to be utilized for fast and highly sensitive, reversible, fluorescent determination of dopamine (DA) in the presence of dopamine, other biomolecules and ions. The X-ray Photoelectron Spectroscopy(XPS), Powder X-Ray Diffraction(PXRD) and Scanning Electron Microscopy(SEM) revealed the formation of nanoparticles with size ranging from 15 to 20 nm. The composition was revealed by Fourier Transform Infrared(FTIR) Spectoscopy and Energy Dispersive X-Ray (EDX) Analysis. The Limits of Detection(LOD) were noted to be 5.57nM and 6.07nM. The binding of DA is noted to be reversible with respect to EDTA2-. Furthermore, the developed sensor exhibited good repeatability, satisfactory long-term stability, and was successfully used for the selective detection of dopamine sample with desired recoveries or reversibilities. The main aim of our work is to selectively detect dopamine in presence of its major interferents and biomolecules that are normally present/ co-exist with dopamine in biological systems.

Chemoarchitectural signatures of subcortical shape alterations in generalized epilepsy

Genetic generalized epilepsies (GGE) exhibit widespread morphometric alterations in the subcortical structures. Subcortical structures are essential for understanding GGE pathophysiology, but their fine-grained morphological diversity has yet to be comprehensively investigated. Furthermore, the relationships between macroscale morphological disturbances and microscale molecular chemoarchitectures are unclear. High-resolution structural images were acquired from patients with GGE (n = 97) and sex- and age-matched healthy controls (HCs, n = 184). Individual measurements of surface shape features (thickness and surface area) of seven bilateral subcortical structures were quantified. The patients and HCs were then compared vertex-wise, and shape anomalies were co-located with brain neurotransmitter profiles. We found widespread morphological alterations in GGE and prominent disruptions in the thalamus, putamen, and hippocampus. Shape area dilations were observed in the bilateral ventral, medial, and right dorsal thalamus, as well as the bilateral lateral putamen. We found that the shape area deviation pattern was spatially correlated with the norepinephrine transporter and nicotinic acetylcholine (Ach) receptor (α4β2) profiles, but a distinct association was seen in the muscarinic Ach receptor (M1). The findings provided a comprehensive picture of subcortical morphological disruptions in GGE, and further characterized the associated molecular mechanisms. This information may increase our understanding of the pathophysiology of GGE.

Brain structural changes and molecular analyses in children with benign epilepsy with centrotemporal spikes

BACKGROUND

Benign epilepsy with centrotemporal spikes (BECTS) is a common childhood epilepsy syndrome, accompanied by behavioral problems and cognitive impairments. Previous studies of BECTS-related brain structures applied univariate analysis and showed inconsistent results. And neurotransmitter patterns associated with brain structural alterations were still unclear.

METHODS

Structural images of twenty-one drug-naïve children with BECTS and thirty-five healthy controls (HCs) were scanned. Segmented gray matter volume (GMV) images were decomposed into independent components (ICs) using the source-based morphometry method. Then spatial correlation analyses were applied to examine possible relationships between GMV changes and neurotransmitter systems.

RESULTS

Compared with HCs, drug-naïve children with BECTS showed increased volume in one GMV component (IC7), including bilateral precentral gyrus, bilateral supplementary motor area, left superior frontal cortex, bilateral middle/ inferior frontal cortex and bilateral anterior/ middle cingulate cortex. A positive correlation was observed between one GMV component (IC6) and seizure frequency. There were significantly positive correlations between abnormal GMV in IC7 and serotonergic, GABAergic and glutamatergic systems.

CONCLUSION

These findings provided further evidence of changed GMV in drug-naïve children with BECTS related to their behavioral problems and cognitive impairments, and associated neurotransmitters which could help to better understand neurobiological mechanisms and underlying molecular mechanisms of BECTS.

IMPACT

The article provides further evidence of changed gray matter volume in drug-naïve children with BECTS related to their behavioral problems and cognitive impairments as well as associated neurotransmitters. Most literature to date has applied univariate analysis and showed inconsistent results, and neurotransmitter patterns associated with brain structural alterations were still unclear. Therefore, this article uses multivariate method and JuSpace toolbox to fill the gap. Significantly increased gray matter volume was found in drug-naïve children with BECTS compared with healthy controls. Abnormal gray matter volume was significantly correlated with clinical data and specific neurotransmitters.

Effect of prednisolone in a kindling model of epileptic seizures in rats on cytokine and intestinal microbiota diversity

Epilepsy is a neurological disease characterized by spontaneous and recurrent seizures. Epileptic seizures can be initiated and facilitated by inflammatory mechanisms. As the dysregulation of the immune system would be involved in epileptogenesis, it is suggested that anti-inflammatory medications could impact epileptic seizures. These medications could potentially have a side effect by altering the structure and composition of the intestinal microbiota. These changes can disrupt microbial homeostasis, leading to dysbiosis and potentially exacerbating intestinal inflammation. We hypothesize that prednisolone may affect the development of epileptic seizures, potentially influencing the diversity of the intestinal microbiota and the regulation of pro-inflammatory cytokines in intestinal tissue. This study aimed to evaluate the effects of prednisolone treatment on epileptic seizures and investigate the effect of this drug on the bacterial diversity of the intestinal microbiota and markers of inflammatory processes in intestinal tissue. We used Male Wistar rat littermates (n = 31, 90-day-old) divided into four groups: positive control treated with 2 mg/kg of diazepam (n = 6), negative control treated with 0.9 g% sodium chloride (n = 6), and the remaining two groups were subjected to treatment with prednisolone, with one receiving 1 mg/kg (n = 9) and the other 5 mg/kg (n = 10). All administrations were performed intraperitoneally (i.p.) over 14 days. To induce the chronic model of epileptic seizures, we administered pentylenetetrazole (PTZ) 25 mg/kg i.p. on alternate days. Seizure latency (n = 6 - 10) and TNF-α and IL-1β concentrations from intestinal samples were measured by ELISA (n = 6 per group), and intestinal microbiota was evaluated with intergenic ribosomal RNA (rRNA) spacer (RISA) analysis (n = 6 per group). The prednisolone treatment demonstrated an increase in the latency time of epileptic seizures and TNF-α and IL-1β concentrations compared to controls. There was no statistically significant difference in intestinal microbiota diversity between the different treatments. However, there was a strong positive correlation between microbial diversity and TNF-α and IL-1β concentrations. The administration of prednisolone yields comparable results to diazepam on increasing latency between seizures, exhibiting promise for its use in clinical studies. Although there were no changes in intestinal microbial diversity, the increase in the TNF-α and IL-1β cytokines in intestinal tissue may be linked to immune system signaling pathways involving the intestinal microbiota. Additional research is necessary to unravel the intricacies of these pathways and to understand their implications for clinical practice.

Neuroinflammation: A Critical Factor in Neurodegenerative Disorders

This review offers a comprehensive review of the signals and the paramount role neuroinflammation plays in neurodegenerative diseases such as Alzheimer's, Parkinson's, Huntington's, and amyotrophic lateral sclerosis. The study explores the sophisticated interactions between microglial, astrocytic, and dendritic cells and how neuroinflammation affects long-term neuronal damage and dysfunction. There are specific pathways related to the mentioned inflammatory processes, including Janus kinases/signal transducer and activator of transcriptions, nuclear factor-κB, and mitogen-activated protein kinases pathways. Neuroinflammation is argued to be a double-edged sword, being not only a protective agent that prevents further neuron damage but also the causative factor in more cell injury development. This concept of contrasting inflammation with neuroprotection advocates for the use of therapeutic techniques that seek to modulate neuroinflammatory responses as part of the neurodegeneration treatment. The recent research findings are integrated with the established knowledge to help present a comprehensive image of neuroinflammation's impact on neurodegenerative diseases and its implications for future therapy.

The Use of Compounds Derived from Cannabis sativa in the Treatment of Epilepsy, Painful Conditions, and Neuropsychiatric and Neurodegenerative Disorders

Neurological disorders present a wide range of symptoms and challenges in diagnosis and treatment. Cannabis sativa, with its diverse chemical composition, offers potential therapeutic benefits due to its anticonvulsive, analgesic, anti-inflammatory, and neuroprotective properties. Beyond cannabinoids, cannabis contains terpenes and polyphenols, which synergistically enhance its pharmacological effects. Various administration routes, including vaporization, oral ingestion, sublingual, and rectal, provide flexibility in treatment delivery. This review shows the therapeutic efficacy of cannabis in managing neurological disorders such as epilepsy, neurodegenerative diseases, neurodevelopmental disorders, psychiatric disorders, and painful pathologies. Drawing from surveys, patient studies, and clinical trials, it highlights the potential of cannabis in alleviating symptoms, slowing disease progression, and improving overall quality of life for patients. Understanding the diverse therapeutic mechanisms of cannabis can open up possibilities for using this plant for individual patient needs.

State- and frequency-dependence in autonomic rebalance mediated by intradermal auricular electroacupuncture stimulation

Background

Vagus nerve stimulation (VNS) improves diseases such as refractory epilepsy and treatment-resistant depression, likely by rebalancing the autonomic nervous system (ANS). Intradermal auricular electro-acupuncture stimulation (iaES) produces similar effects. The aim of this study was to determine the effects of different iaES frequencies on the parasympathetic and sympathetic divisions in different states of ANS imbalance.

Methods

We measured heart rate variability (HRV) and heart rate (HR) of non-modeled (normal) rats with the treatment of various frequencies to determine the optimal iaES frequency. The optimized iaES frequency was then applied to ANS imbalance model rats to elucidate its effects.

Results

30 Hz and 100 Hz iaES clearly affected HRV and HR in normal rats. 30 Hz iaES increased HRV, and decreased HR. 100 Hz iaES decreased HRV, and increased HR. In sympathetic excited state rats, 30 Hz iaES increased HRV. 100 Hz iaES increased HRV, and decreased HR. In parasympathetic excited state rats, 30 Hz and 100 Hz iaES decreased HRV. In sympathetic inhibited state rats, 30 Hz iaES decreased HRV, while 100 Hz iaES decreased HR. In parasympathetic inhibited rats, 30 Hz iaES decreased HR and 100 Hz iaES increased HRV.

Conclusion

30 Hz and 100 Hz iaES contribute to ANS rebalance by increasing vagal and sympathetic activity with different amplifications. The 30 Hz iaES exhibited positive effects in all the imbalanced states. 100 Hz iaES suppressed the sympathetic arm in sympathetic excitation and sympathetic/parasympathetic inhibition and suppressed the vagal arm and promoted the sympathetic arm in parasympathetic excitation and normal states.

Mechanism of NLRP3 Inflammasome in Epilepsy and Related Therapeutic Agents

Epilepsy is one of the most widespread and complex diseases in the central nervous system (CNS), affecting approximately 65 million people globally, an important factor resulting in neurological disability-adjusted life year (DALY) and progressive cognitive dysfunction. Medication is the most essential treatment. The currently used drugs have shown drug resistance in some patients and only control symptoms; the development of novel and more efficacious pharmacotherapy is imminent. Increasing evidence suggests neuroinflammation is involved in the occurrence and development of epilepsy, and high expression of NLRP3 inflammasome has been observed in the temporal lobe epilepsy (TLE) brain tissue of patients and animal models. The inflammasome is a crucial cause of neuroinflammation by activating IL-1β and IL-18. Many preclinical studies have confirmed that regulating NLRP3 inflammasome pathway can prevent the development of epilepsy, reduce the severity of epilepsy, and play a neuroprotective role. Therefore, regulating NLRP3 inflammasome could be a potential target for epilepsy treatment. In summary, this review describes the priming and activation of inflammasome and its biological function in the progression of epilepsy. In addition, we reviewes the current pharmacological researches for epilepsy based on the regulation of NLRP3 inflammasome, aiming to provide a basis and reference for developing novel antiepileptic drugs.

Behavioral and neurotransmitter changes on antiepileptic drugs treatment in the zebrafish pentylenetetrazol-induced seizure model

Epilepsy, a recurrent neurological disorder involving abnormal neurotransmitter kinetics in the brain, has emerged as a global health concern. The mechanism of epileptic seizures is thought to involve a relative imbalance between excitatory and inhibitory neurotransmitters. Despite the recent advances in clinical and basic research on the pathogenesis of epilepsy, the complex relationship between the neurotransmitter changes and behavior with and without antiepileptic drugs (AEDs) during seizures remains unclear. To investigate the effects of AEDs such as levetiracetam (LEV), carbamazepine (CBZ), and fenfluramine (FFR) on key neurotransmitters in the pentylenetetrazol (PTZ)-induced seizures in adult zebrafish, we examined the changes in glutamic acid, gamma-aminobutyric acid (GABA), serotonin (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), choline, acetylcholine, norepinephrine, dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), and adenosine. In this study, we observed that 5-HT and DA levels in the brain increased immediately after PTZ-induced seizures. Behavioral tests clearly showed that all of these AEDs suppressed the PTZ-induced seizures. Upon treatment of PTZ-induced seizures with these AEDs, CBZ decreased the glutamic acid and FFR increased the GABA levels; however, no neurotransmitter changes were observed in the brain after LEV administration. Thus, we demonstrated a series of neurotransmitter changes linked to behavioral changes during PTZ-induced epileptic seizures when LEV, CBZ, or FFR were administered. These findings will lead to a more detailed understanding of the pathogenesis of epilepsy associated with behavioral and neurotransmitter changes under AED treatment.

Audiogenic kindling activates glutamatergic system in the hippocampus of rats with genetic predisposition to audiogenic seizures

Temporal lobe epilepsy (TLE) development is associated with dysregulation of glutamatergic transmission in the hippocampus; however, detailed molecular mechanisms of pathological changes are still poorly understood. In the present study, we performed the complex analysis of glutamatergic system in the hippocampus of Krushinsky-Molodkina (KM) rats genetically prone to audiogenic seizures (AGS). Daily AGS stimulations (audiogenic kindling) were used to reproduce the dynamics of TLE development. Naïve KM rats were used as a control. After 14 AGS, at the stage of developing TLE, KM rats demonstrated significant upregulation of extracellular signal-regulated kinases (ERK) 1 and 2, cAMP response element-binding protein (CREB), and c-Fos in the hippocampus indicating activation of the hippocampal cells. These changes were accompanied with an increase in glutaminase and vesicular glutamate transporter (VGLUT) 2 suggesting the activation of glutamate production and loading into the synaptic vesicles. After 21 AGS, when TLE was fully-established, alterations were similar but more pronounced, with higher activation of glutaminase, increase in glutamate production, upregulation of VGLUT1 and 2, and Fos-related antigen 1 (Fra-1) along with c-Fos. Analysis of glutamate receptors showed variable changes. Thus, after 14 AGS, simultaneous increase in metabotropic glutamate receptor mGluR1 and decrease in ionotropic N-methyl-D-aspartate (NMDA) receptors could reflect compensatory anti-epileptic mechanism, while further kindling progression induced upregulation of ionotropic receptors, probably, contributing to the hippocampal epileptization. However, we revealed practically no alterations in the expression of synaptic proteins. Altogether, obtained results suggested that overactivation of glutamate production in the hippocampus strongly contributed to TLE development in KM rats.

Anticonvulsive Effect of Glucosyl Xanthone Mangiferin on Pentylenetetrazol (PTZ)-Induced Seizure-Provoked Mice

Anxiety and depression are major side effects induced by currently available antiepileptic drugs; apart from this, they also diminish intelligence and language skills which cause hepatic failure, anemia, etc. Hence, in this study, we assessed antiepileptic effect of a phytochemical mangiferin. Epilepsy, a prevalent non communicable neurological disorder, affects infants and older population throughout the world. Epilepsy-induced comorbidities are more severe and if not treated cautiously lead to disability and even worse cases, mortality. The onset and duration of convulsion were observed. Seizure severity score was assessed by provoking kindling with 35 mg/kg PTZ. Prooxidants and antioxidants were measured to assess the antioxidant effect of mangiferin. Inflammatory markers were measured to determine the anti-inflammatory effect of mangiferin. The levels of neurotransmitters and ATPases were quantified to evaluate the neuroprotective effect of mangiferin. Mangiferin significantly decreased the onset and duration convulsion. It also decreased the seizure severity score, locomotor activity, and immobilization effectively. The excitatory neurotransmitter was reduced, and inhibitory neurotransmitter was increased in mice treated with mangiferin. Overall, our results confirm that mangiferin efficiently protects mice from PTZ-induced seizures. It can be subjected to further research to be prescribed as a potent antiepileptic drug.

Unraveling the Neural Circuits: Techniques, Opportunities and Challenges in Epilepsy Research

Epilepsy, a prevalent neurological disorder characterized by high morbidity, frequent recurrence, and potential drug resistance, profoundly affects millions of people globally. Understanding the microscopic mechanisms underlying seizures is crucial for effective epilepsy treatment, and a thorough understanding of the intricate neural circuits underlying epilepsy is vital for the development of targeted therapies and the enhancement of clinical outcomes. This review begins with an exploration of the historical evolution of techniques used in studying neural circuits related to epilepsy. It then provides an extensive overview of diverse techniques employed in this domain, discussing their fundamental principles, strengths, limitations, as well as their application. Additionally, the synthesis of multiple techniques to unveil the complexity of neural circuits is summarized. Finally, this review also presents targeted drug therapies associated with epileptic neural circuits. By providing a critical assessment of methodologies used in the study of epileptic neural circuits, this review seeks to enhance the understanding of these techniques, stimulate innovative approaches for unraveling epilepsy's complexities, and ultimately facilitate improved treatment and clinical translation for epilepsy.

Knockdown of SIK3 in the CA1 Region can Reduce Seizure Susceptibility in Mice by Inhibiting Decreases in GABAAR α1 Expression

Imbalance between excitation and inhibition is an important cause of epilepsy. Salt-inducible kinase 1 (SIK1) gene mutation can cause epilepsy. In this study, we first found that the expression of SIK3 is increased after epilepsy. Furthermore, the role of SIK3 in epilepsy was explored. In cultured hippocampal neurons, we used Pterosin B, a selective SIK3 inhibitor that can inhibit epileptiform discharges induced by the convulsant drug cyclothiazide (a positive allosteric modulator of AMPA receptors, CTZ). Knockdown of SIK3 inhibited epileptiform discharges and increased the amplitude of miniature inhibitory postsynaptic currents (mIPSCs). In mice, knockdown of SIK3 reduced epilepsy susceptibility in a pentylenetetrazole (a GABAA receptor antagonist, PTZ) acute kindling experiment and increased the expression of GABAA receptor α1. In conclusion, our results suggest that blockade or knockdown of SIK3 can inhibit epileptiform discharges and that SIK3 has the potential to be a novel target for epilepsy treatment.

Ketogenic diet-produced β-hydroxybutyric acid accumulates brain GABA and increases GABA/glutamate ratio to inhibit epilepsy

Ketogenic diet (KD) alleviates refractory epilepsy and reduces seizures in children. However, the metabolic/cell biologic mechanisms by which the KD exerts its antiepileptic efficacy remain elusive. Herein, we report that KD-produced β-hydroxybutyric acid (BHB) augments brain gamma-aminobutyric acid (GABA) and the GABA/glutamate ratio to inhibit epilepsy. The KD ameliorated pentetrazol-induced epilepsy in mice. Mechanistically, KD-produced BHB, but not other ketone bodies, inhibited HDAC1/HDAC2, increased H3K27 acetylation, and transcriptionally upregulated SIRT4 and glutamate decarboxylase 1 (GAD1). BHB-induced SIRT4 de-carbamylated and inactivated glutamate dehydrogenase to preserve glutamate for GABA synthesis, and GAD1 upregulation increased mouse brain GABA/glutamate ratio to inhibit neuron excitation. BHB administration in mice inhibited epilepsy induced by pentetrazol. BHB-mediated relief of epilepsy required high GABA level and GABA/glutamate ratio. These results identified BHB as the major antiepileptic metabolite of the KD and suggested that BHB may serve as an alternative and less toxic antiepileptic agent than KD.

Advances in understanding the pathogenesis of epilepsy: Unraveling the molecular mechanisms: A cross-sectional study

Introduction

Epilepsy is characterized by having two or more unprovoked seizures. Understanding the pathogenesis of epilepsy, requires deep investigation into the molecular mechanisms. This helps develop diagnostic techniques, treatments, and pharmacotherapy. It also enhances precision medicine and individualized treatment processes. This article reviews all the molecular mechanisms predisposing to epileptogenesis, presents the current diagnostic techniques and drug therapy, and suggests future perspectives in treating Epilepsy in a more comprehensive and holistic approach.

Methodology

Four authors searched keywords concerning epilepsy at a molecular level, Epilepsy diagnostic techniques and technologies, and antiepileptic drug therapy and precision medicine. Separate search strategies were conducted for each concern and retrieved articles were reviewed for relevant results.

Results

The traditional diagnostic techniques for Epilepsy and its pathogenesis are insufficient in highlighting dynamic brain changes. For this, emerging technologies including genetic sequencing and profiling, and functional neuroimaging techniques are prevailing. Concerning treatment, the current approach focuses on managing symptoms and stopping seizures using antiseizure medications. However, their usage is limited by developing resistance to such drugs. Some therapies show promise, although most antiseizure drugs do not prevent epilepsy.

Discussion

Understanding epileptogenesis at a molecular and genetic level aids in developing new antiepileptic pharmacotherapy. The aim is to develop therapies that could prevent seizures or modify disease course, decreasing the severity and avoiding drug resistance. Gene therapy and precision medicine are promising but applications are limited due to the heterogeneity in studying the Epileptic brain, dynamically. The dynamic investigation of the epileptic brain with its comorbidities works hand-in-hand with precision medicine, in developing personalized treatment plans.

Metabotropic glutamate receptors (mGluRs) in epileptogenesis: an update on abnormal mGluRs signaling and its therapeutic implications

Epilepsy is a neurological disorder characterized by high morbidity, high recurrence, and drug resistance. Enhanced signaling through the excitatory neurotransmitter glutamate is intricately associated with epilepsy. Metabotropic glutamate receptors (mGluRs) are G protein-coupled receptors activated by glutamate and are key regulators of neuronal and synaptic plasticity. Dysregulated mGluR signaling has been associated with various neurological disorders, and numerous studies have shown a close relationship between mGluRs expression/activity and the development of epilepsy. In this review, we first introduce the three groups of mGluRs and their associated signaling pathways. Then, we detail how these receptors influence epilepsy by describing the signaling cascades triggered by their activation and their neuroprotective or detrimental roles in epileptogenesis. In addition, strategies for pharmacological manipulation of these receptors during the treatment of epilepsy in experimental studies is also summarized. We hope that this review will provide a foundation for future studies on the development of mGluR-targeted antiepileptic drugs.

Nomo1 deficiency causes autism-like behavior in zebrafish

Patients with neuropsychiatric disorders often exhibit a combination of clinical symptoms such as autism, epilepsy, or schizophrenia, complicating diagnosis and development of therapeutic strategies. Functional studies of novel genes associated with co-morbidities can provide clues to understand the pathogenic mechanisms and interventions. NOMO1 is one of the candidate genes located at 16p13.11, a hotspot of neuropsychiatric diseases. Here, we generate nomo1-/- zebrafish to get further insight into the function of NOMO1. Nomo1 mutants show abnormal brain and neuronal development and activation of apoptosis and inflammation-related pathways in the brain. Adult Nomo1-deficient zebrafish exhibit multiple neuropsychiatric behaviors such as hyperactive locomotor activity, social deficits, and repetitive stereotypic behaviors. The Habenular nucleus and the pineal gland in the telencephalon are affected, and the melatonin level of nomo1-/- is reduced. Melatonin treatment restores locomotor activity, reduces repetitive stereotypic behaviors, and rescues the noninfectious brain inflammatory responses caused by nomo1 deficiency. These results suggest melatonin supplementation as a potential therapeutic regimen for neuropsychiatric disorders caused by NOMO1 deficiency.

Pathophysiology to Risk Factor and Therapeutics to Treatment Strategies on Epilepsy

Epilepsy represents a condition in which abnormal neuronal discharges or the hyperexcitability of neurons occur with synchronicity, presenting a significant public health challenge. Prognostic factors, such as etiology, electroencephalogram (EEG) abnormalities, the type and number of seizures before treatment, as well as the initial unsatisfactory effects of medications, are important considerations. Although there are several third-generation antiepileptic drugs currently available, their multiple side effects can negatively affect patient quality of life. The inheritance and etiology of epilepsy are complex, involving multiple underlying genetic and epigenetic mechanisms. Different neurotransmitters play crucial roles in maintaining the normal physiology of different neurons. Dysregulations in neurotransmission, due to abnormal transmitter levels or changes in their receptors, can result in seizures. In this review, we address the roles played by various neurotransmitters and their receptors in the pathophysiology of epilepsy. Furthermore, we extensively explore the neurological mechanisms involved in the development and progression of epilepsy, along with its risk factors. Furthermore, we highlight the new therapeutic targets, along with pharmacological and non-pharmacological strategies currently employed in the treatment of epileptic syndromes, including drug interventions employed in clinical trials related to epilepsy.

Inhibitory control deficits in patients with mesial temporal lobe epilepsy: an event-related potential analysis based on Go/NoGo task

Objective

Neuropsychiatric comorbidities are common among patients with mesial temporal lobe epilepsy (MTLE). One of these comorbidities, impulsivity, can significantly impact the quality of life and prognosis. However, there have been few studies of impulsivity in these patients, and the existing findings are inconsistent. The present study investigates impulsivity in MTLE patients from the perspective of inhibitory control and its underlying processes using event-related potentials (ERPs) initiated using a Go/NoGo task.

Methods

A total of 25 MTLE patients and 25 age-, gender-, and education-matched healthy controls (HCs) completed an unequal visual Go/NoGo task. Different waveforms as well as behavioral measures were analyzed between Go and NoGo conditions (N2d and P3d). Impulsivity was also assessed using self -rating scales, and clinical variables that may be related to ERPs were explored.

Results

Compared with HCs, MTLE patients exhibited significantly longer reaction time (RT) (p = 0.002) and lower P3d especially at the frontal electrode sites (p = 0.001). In the MTLE group, the seizure frequency (p = 0.045) and seizure types (p < 0.001) were correlated with the P3d amplitude. A self-rated impulsivity assessment revealed that MTLE patients had higher non-planning (p = 0.017) and total scores (p = 0.019) on the BIS-11 as well as higher DI (p = 0.010) and lower FI (p = 0.007) on the DII.

Conclusion

The findings demonstrate that the presence of inhibitory control deficits in patients with MTLE are characterized by deficits in the late stage of inhibition control, namely the motor inhibition stage. This study improves our understanding of impulsivity in MTLE patients and suggests that ERPs may constitute a sensitive means of detecting this trait.

Children with Autism Spectrum Disorder and Abnormalities of Clinical EEG: A Qualitative Review

Over the last decade, the comorbidity between Autism Spectrum Disorder (ASD) and epilepsy has been widely demonstrated, and many hypotheses regarding the common neurobiological bases of these disorders have been put forward. A variable, but significant, prevalence of abnormalities on electroencephalogram (EEG) has been documented in non-epileptic children with ASD; therefore, several scientific studies have recently tried to demonstrate the role of these abnormalities as a possible biomarker of altered neural connectivity in ASD individuals. This narrative review intends to summarize the main findings of the recent scientific literature regarding abnormalities detected with standard EEG in children/adolescents with idiopathic ASD. Research using three different databases (PubMed, Scopus and Google Scholar) was conducted, resulting in the selection of 10 original articles. Despite an important lack of studies on preschoolers and a deep heterogeneity in results, some authors speculated on a possible association between EEG abnormalities and ASD characteristics, in particular, the severity of symptoms. Although this correlation needs to be more strongly elucidated, these findings may encourage future studies aimed at demonstrating the role of electrical brain abnormalities as an early biomarker of neural circuit alterations in ASD, highlighting the potential diagnostic, prognostic and therapeutic value of EEG in this field.

The Role of the Vagus Nerve in the Microbiome and Digestive System in Relation to Epilepsy

The Enteric Nervous System (ENS) is described as a division of the Peripheral Nervous System (PNS), located within the gut wall and it is formed by two main plexuses: the myenteric plexus (Auerbach's) and the submucosal plexus (Meissner's). The contribution of the ENS to the pathophysiology of various neurological diseases such as Parkinson's or Alzheimer's disease has been described in the literature, while some other studies have found a connection between epilepsy and the gastrointestinal tract. The above could be explained by cholinergic neurons and neurotransmission systems in the myenteric and submucosal plexuses, regulating the vagal excitability effect. It is also understandable, as the discharges arising in the amygdala are transmitted to the intestine through projections the dorsal motor nucleus of the vagus, giving rise to efferent fibers that stimulate the gastrointestinal tract and consequently the symptoms at this level. Therefore, this review's main objective is to argue in favor of the existing relationship of the ENS with the Central Nervous System (CNS) as a facilitator of epileptogenic or ictogenic mechanisms. The gut microbiota also participates in this interaction; however, it depends on many individual factors of each human being. The link between the ENS and the CNS is a poorly studied epileptogenic site with a big impact on one of the most prevalent neurological conditions such as epilepsy.

Simultaneous determination of human plasma 5 amino acid neurotransmitters using liquid chromatography-tandem mass spectrometry: Establishment of reference intervals in Chinese adult population and application to patients with schizophrenia

Schizophrenia is a serious mental disease with unknown etiology that affects approximately 1 % of the population around the world. Altered levels of amino acid neurotransmitters may underlie the physiopathology of schizophrenia (SZ). This study aimed to develop a rapid and robust liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous determination of glutamate acid (Glu), aspartic acid (Asp), γ-aminobutyric acid (GABA), glycine acid (Gly), and Taurine acid (Tau) in patients with schizophrenia plasma and establish reference intervals for Chinese adult populations, and applied to patients with schizophrenia for a preliminary exploration of changes in their plasma levels of five amino acid neurotransmitters. Sample treatment involved protein precipitation followed by dansyl chloride (DNS-Cl) derivatization and total run time is 5.8 min. The method was validated according to the latest national and international guidelines, which achieved acceptable precision (0.54-14.54 %) and accuracy (97.06-103.82 %). The reference interval for Glu, Asp, Gly, Tau, and GABA were 55.51-189.06, 27.51-92.38, 204.01-574.55, 107.50-227.65, and <1 μmol/L, respectively. Increased Tau levels and decreased Asp and Glu levels were shown in patients with schizophrenia. This method was suitable for clinical routine detection of plasma 5 amino acid neurotransmitters in Chinese adult populations.