Regulation of specific abnormal calcium signals in the hippocampal CA1 and primary cortex M1 alleviates the progression of temporal lobe epilepsy

Temporal lobe epilepsy is a multifactorial neurological dysfunction syndrome that is refractory,resistant to antiepileptic drugs,and has a high recurrence rate.The pathogenesis of temporal lobe epilepsy is complex and is not fully understood.Intracellular calcium dynamics have been implicated in temporal lobe epilepsy.However,the effect of fluctuating calcium activity in CA1 pyramidal neurons on temporal lobe epilepsy is unknown,and no longitudinal studies have investigated calcium activity in pyramidal neurons in the hippocampal CA1 and primary motor cortex M1 of freely moving mice.In this study,we used a multichannel fiber photometry system to continuously record calcium signals in CA1 and M1 during the temporal lobe epilepsy process.We found that calcium signals varied according to the grade of temporal lobe epilepsy episodes.In particular,cortical spreading depression,which has recently been frequently used to represent the continuously and substantially increased calcium signals,was found to correspond to complex and severe behavioral characteristics of temporal lobe epilepsy ranging from gradeⅡto gradeⅤ.However,vigorous calcium oscillations and highly synchronized calcium signals in CA1 and M1 were strongly related to convulsive motor seizures.Chemogenetic inhibition of pyramidal neurons in CA1 significantly attenuated the amplitudes of the calcium signals corresponding to gradeⅠepisodes.In addition,the latency of cortical spreading depression was prolonged,and the above-mentioned abnormal calcium signals in CA1 and M1 were also significantly reduced.Intriguingly,it was possible to rescue the altered intracellular calcium dynamics.Via simultaneous analysis of calcium signals and epileptic behaviors,we found that the progression of temporal lobe epilepsy was alleviated when specific calcium signals were reduced,and that the end-point behaviors of temporal lobe epilepsy were improved.Our results indicate that the calcium dynamic between CA1 and M1 may reflect specific epileptic behaviors corresponding to different grades.Furthermore,the selective regulation of abnormal calcium signals in CA1 pyramidal neurons appears to effectively alleviate temporal lobe epilepsy,thereby providing a potential molecular mechanism for a new temporal lobe epilepsy diagnosis and treatment strategy.

Cognitive Disorders, Depression and Anxiety in Temporal Lobe Epilepsy: An Overview

Partial epilepsies, originating in a specific brain region, affect about 60% of adults with epilepsy. Temporal lobe epilepsy (TLE) is the most prevalent subtype within this category, often necessitating surgical intervention due to its refractoriness to antiepileptic drugs (AEDs). Hippocampal sclerosis, a common underlying pathology, often exacerbates the severity by introducing cognitive and emotional challenges. This review delves deeper into the cognitive profile of TLE, along with the risk factors for cognitive disorders, depression, and anxiety in this population.

MicroRNAs as potential biomarkers in temporal lobe epilepsy and mesial temporal lobe epilepsy

Temporal lobe epilepsy is the most common form of focal epilepsy in adults,accounting for one third of all diagnosed epileptic patients,with seizures originating from or involving mesial temporal structures such as the hippocampus,and many of these patients being refractory to treatment with anti-epileptic drugs.Temporal lobe epilepsy is the most common childhood neurological disorder and,compared with adults,the symptoms are greatly affected by age and brain development.Diagnosis of temporal lobe epilepsy relies on clinical examination,patient history,electroencephalographic recordings,and brain imaging.Misdiagnosis or delay in diagnosis is common.A molecular biomarker that could distinguish epilepsy from healthy subjects and other neurological conditions would allow for an earlier and more accurate diagnosis and appropriate treatment to be initiated.Among possible biomarkers of pathological changes as well as potential therapeutic targets in the epileptic brain are micro RNAs.Most of the recent studies had performed micro RNA profiling in body fluids such as blood plasma and blood serum and brain tissues such as temporal cortex tissue and hippocampal tissue.A large number of micro RNAs were dysregulated when compared to healthy controls and with some overlap between individual studies that could serve as potential biomarkers.For example,in adults with temporal lobe epilepsy,possible biomarkers are miR-199a-3p in blood plasma and miR-142-5p in blood plasma and blood serum.In adults with mesial temporal lobe epilepsy,possible biomarkers are miR-153 in blood plasma and miR-145-3p in blood serum.However,in many of the studies involving patients who receive one or several anti-epileptic drugs,the influence of these on micro RNA expression in body fluids and brain tissues is largely unknown.Further studies are warranted with children with temporal lobe epilepsy and consideration should be given to utilizing mouse or rat and non-human primate models of temporal lobe epilepsy.The animal models could be used to confirm micro RNA findings in human patients and to test the effects of targeting specific micro RNAs on disease progression and behavior.

Activation of medial septum cholinergic neurons restores cognitive function in temporal lobe epilepsy

Cognitive impairment is the most common complication in patients with temporal lobe epilepsy with hippocampal scle rosis.There is no effective treatment for cognitive impairment.Medial septum cholinergic neurons have been reported to be a potential target for controlling epileptic seizures in tempo ral lobe epile psy.However,their role in the cognitive impairment of temporal lobe epilepsy remains unclear.In this study,we found that patients with temporal lobe epile psy with hippocampal sclerosis had a low memory quotient and severe impairment in verbal memory,but had no impairment in nonverbal memory.The cognitive impairment was slightly correlated with reduced medial septum volume and medial septum-hippocampus tra cts measured by diffusion tensor imaging.In a mouse model of chronic temporal lobe epilepsy induced by kainic acid,the number of medial septum choline rgic neurons was reduced and acetylcholine release was reduced in the hippocampus.Furthermore,selective apoptosis of medial septum cholinergic neurons mimicked the cognitive deficits in epileptic mice,and activation of medial septum cholinergic neurons enhanced hippocampal acetylcholine release and restored cognitive function in both kainic acid-and kindling-induced epile psy models.These res ults suggest that activation of medial septum cholinergic neurons reduces cognitive deficits in temporal lobe epilepsy by increasing acetylcholine release via projections to the hippocampus.

DIAGNOSTIC VALUE OF INTERICTAL DIFFUSION-WEIGHTED IMAGING IN EVALUATION OF INTRACTABLE TEMPORAL LOBE EPILEPSY

Objective To explore the ability of interictal diffusion-weighted imaging(DWI)to localize the temporal lobe of seizure origin and to predict postoperative seizure control in patients with temporal lobe epilepsy(TLE).Methods Twenty-seven patients with intractable TLE considered for surgery and 19 healthy volunteers were studied with conventional magnetic resonance imaging(MRI)and DWI.Apparent diffusion coefficients(ADCs)of bilateral hippocampi in both TLE patients and control subjects were obtained.Lateralization to either temporal lobe with hippocampal ADC was based on the threshold values derived from ±1SD of right/left ratios in normal subjects.And the postoperative pathology was reviewed.Results Hippocampal ADCs were higher on the side of surgery compared with those on the contralateral side as well as the ipsilateral side in control subjects [resected side(109.8±7.3)×10-5 cm2/s,contralateral side(91.7±4.7)×10-5 cm2/s,control subjects(81.6±5.2)×10-5 cm2/s,all P<0.01].Right/left hippocampal ADC ratio and conventional MRI lateralized to the operated temporal lobe in 21 of 27(77.8%)and in 18 of 27(66.7%)patients.Lateralization to the surgical side was not associated with postoperative seizure control with right/left hippocampal ADC ratio(P>0.05).Conclusions Conventional MRI is a sensitive method to detect hippocampal sclerosis.Accuracy of the right/left hippocampal ADC ratio for lateralizing to the side of surgery is very high,but it isn't a better predictor of surgical outcome.

Anomalous expression of chloride transporters in the sclerosed hippocampus of mesial temporal lobe epilepsy patients

The Na＋-K＋-CI- cotransporter 1 and K＋-CI- cotransporter 2 regulate the levels of intracellular chloride in hippocampal cells. Impaired chloride transport by these proteins is thought to be involved in the pathophysiological mechanisms of mesial temporal lobe epilepsy. Imbalance in the relative expression of these two proteins can lead to a collapse of CI- homeostasis, resulting in a loss of gamma-aminobutyric acid-ergic inhibition and even epileptiform discharges. In this study, we investigated the expression of Na＋-K＋-CI- cotransporter 1 and K＋-CI- cotransporter 2 in the sclerosed hippocampus of patients with mesial temporal lobe epilepsy, using western blot analysis and immunohistochemistry. Compared with the histologically normal hippocampus, the sclerosed hippocampus showed increased Na＋-K＋-Cl- cotransporter 1 expression and decreased K＋-CI- cotransporter 2 expression, especially in CA2 and the dentate gyrus. The change was more prominent for the Na＋-K＋-CI- cotransporter 1 than for the K＋-CI- cotransporter 2. These experimental findings indicate that the balance between intracellular and extracellular chloride may be disturbed in hippocampal sclerosis, contributing to the hyperexcitability underlying epileptic seizures. Changes in Na＋-K＋-CI-cotransporter 1 expression seems to be the main contributor. Our study may shed new light on possible therapies for patients with mesial temporal lobe epilepsy with hippocampal sclerosis.

Increased expression of Notch1 in temporal lobe epilepsy: animal models and clinical evidence

Temporal lobe epilepsy is associated with astrogliosis. Notchl signaling can induce astrogliosis in glioma. However, it remains unknown whether Notchl signaling is involved in the pathogenesis of epilepsy. This study investigated the presence of Notchl, hairy and enhancer of split-l, and glial fibrillary acidic protein in the temporal neocortex and hippocampus of lithium-pilocar- pine-treated rats. The presence of Notchl and hairy and enhancer of split-1 was also explored in brain tissues of patients with intractable temporal lobe epilepsy. Quantitative electroencephalo- gram analysis and behavioral observations were used as auxiliary measures. Results revealed that the presence of Notchl, hairy and enhancer of split-l, and glial fibriUary acidic protein were en- hanced in status epilepticus and vehicle-treated spontaneous recurrent seizures rats, but remain unchanged in the following groups： control, absence of either status epilepticus or spontaneous recurrent seizures, and zileuton-treated spontaneous recurrent seizures. Compared with patient control cases, the presences of Notch1 and hairy and enhancer of split- 1 were upregulated in the temporal neocortex of patients with intractable temporal lobe epilepsy. Therefore, these results suggest that Notchl signaling may play an important role in the onset of temporal lobe epilepsy via astrogliosis. Furthermore, zileuton may be a potential therapeutic strategy for temporal lobe epilepsy by blocking Notchl signaling.

Spatio-temporal Expression Study of Phosphorylated 70-kDa Ribosomal S6 Kinase (p70S6k) in Mesial Temporal Lobe Epilepsy

Objective To determine the spatio-temporal expression of p70S6k activation in hippocampus in mesial temporal lobe epilepsy. Methods Temporal lobe epilepsy model was established by stereotaxically unilateral and intrahip-pocampal injection of kainite acid (KA) in adult male C57BL/6 mice. Latent and chronic epileptogenesis were represented by mice 5 days after KA injection (n=5) and mice 5 weeks after KA injection (n=8), respectively. Control mice (n=5) were injected with saline. Immunohistochemical assays were performed on brain sections of the mice. Results Hippocampus both ipsilateral and contralateral to the KA injection displayed significantly up-regulated pS6 immunoreactivity in dispersed granule cells in 5-day and 5-week model mice. Conclusion The activation of p70S6k is mainly located in the dentate gyrus in KA-induced mouse model of temporal lobe epilepsy, indicating that the activation may be related with the disperse degree and hypertrophy of granule cells.

Research on Medial Temporal Lobe Epilepsy by Combining Structural and Functional MRI

Epilepsy is a common neurological disorder, and its electrophysiology characteristic is abnormally high excitability and synchronization of the neural activity. This paper focuses on the study of medial temporal lobe epilepsy with hippocampal sclerosis. The hippocampus plays an important role in short-term memory. However, little is known about the connectivity between hippocampal structures and adjacent brain regions. The functional and structural connectivity between patients and controls was investigated by using the techniques of functional magnetic resonance imaging and diffusion tensor imaging in the paper. Three pairs of ROIs related to working memory from BOLD-fMRI data were chosen. These ROIs were registrated from MNI space to individual space and the fiber bundle between two ROIs were traced in the DTI images. The results show that the number of fiber bundle of patients reduce among these ROIs, such as left hippocampus and right hippocampus, left hippocampus and left thalamus, left hippocampus and left frontal lobe and so on. And the number of fiber bundle of patients increase among these ROIs, such as left thalamus and right thalamus, right hippocampus and right thalamus. And the FA values of the fiber bundles of patients in some regions related to left hippocampus decrease. The cause of abnormal functional and structural connections due to the damage of hippocampus in medial temporal lobe epilepsy is studied from a new perspective.

METABOLIC ABNORMALITIES IN MESIAL TEMPORAL LOBE EPILEPSY PATIENTS DEPICTED BY PROTON MR SPECTROSCOPY USING A 3.0T MR SCANNER

Objective To evaluate metabolic abnormalities in patients with mesial temporal lobe epilepsy （MTLE） with proton magnetic resonance spectroscopy （MRS） using a 3.0T MR scanner. Methods Sixty-three patients （32 women and 31 men） with diagnosed MTLE underwent diagnostic MR imaging （MRI） and proton MRS using a 3.0T MR scanner. The clinical history and interictal epileptiform discharges （IEDs） were recorded. Sixteen healthy volunteers served as control. The results of proton MRS were compared with the findings of electroencephalogram and structural MRI findings. Results Twenty-seven of the 63 patients with MTLE showed unilateral hippocampal sclerosis, and 9 showed bilateral hippocampal sclerosis. The concentration ratio of N-acytelaspartate （NAA） / [ creatine （ Cr ） ＋ choline （Cho） ] in the hippocampal region of MTLE patients （0. 64±0. 07） was significantly lower than control （0. 80±0. 05, P = 0.023）. In the patients with unilateral hippocampal sclerosis, NAA/（Cr ＋ Cho） in the hippocampal region ipsilateral to the sclerotic hippocampus （0.56±0.06） was significantly lower than the ratio in the contralateral hippocampal region （0.69±0.07, P 〈 0. 001 ）. There was significant difference in hippocampal NAA/（ Cr ＋ Cho） between the refractory patients and the non-refractory patients （0. 64±0. 05 vs.0.71±0. 07, P =0. 04）. Forty-five patients were lateralized by IEDs, while 49 patients were lateralized by metabolite ratio. And lateralization determined by proton MRS and IEDs was concordant in 33 patients. Conclusions MRS as a noninvasive tool adds helpful metabolite information to routine MRI in evaluation of MTLE. The method is well established and should be a routine clinical application in the investigation of epilepsy.

Molecular typing of familial temporal lobe epilepsy

The pathogenesis of temporal lobe epilepsy(TLE)was originally considered to be acquired.However,some reports showed that TLE was clustered in some families,indicating a genetic etiology.With the popularity of genetic testing technology,eleven different types of familial TLE(FTLE),including ETL1-ETL11,have been reported,of which ETL9-ETL11 had not yet been included in the OMIM database.These types of FTLE were caused by different genes/Loci and had distinct characteristics.ETL1,ETL7 and ETL10 were characterized by auditory,visual and aphasia seizures,leading to the diagnosis of familial lateral TLE.ETL2,ETL3 and ETL6 showed prominent autonomic symptom and automatism with or without hippocampal abnormalities,indicating a mesial temporal origin.Febrile seizures were common in FTLEs such as ETL2,ETL5,ETL6 and ETL11.ETL4 was diagnosed as occipitotemporal lobe epilepsy with a high incidence of migraine and visual aura.Considering the diversity and complexity of the symptoms of TLE,neurologists enquiring about the family history of epilepsy should ask whether the relatives of the proband had experienced unnoticeable seizures and whether there is a family history of other neurological diseases carefully.Most FTLE patients had a good prognosis with or without anti-seizure medication treatment,with the exception of patients with heterozygous mutations of the CPA6 gene.The pathogenic mechanism was diverse among these genes and spans disturbances of neuron development,differentiation and synaptic signaling.In this article,we describe the research progress on eleven different types of FTLE.The precise molecular typing of FTLE would facilitate the diagnosis and treatment of FTLE and genetic counseling for this disorder.

Chaihu Longgu Muli Decoction relieving temporal lobe epilepsy in rats by inhibiting TLR4 signaling pathway through miR-146a-3p and miR-146a-5p

Objective To explore the effect and mechanism of Chaihu Longgu Muli Decoction(柴胡龙骨牡蛎汤,CHLGMLD)in rats with temporal lobe epilepsy(TLE).Methods A total of 80 Sprague-Dawley(SD)male rats were randomized into control(CON),model(MOD),carbamazepine(CBZ,0.1 g/kg),CHLGMLD low dose(CHLGMLD-L,12.5 g/kg),and high dose(CHLGMLD-H,25 g/kg)groups,with 16 rats in each group.TLE rat models were established in the four groups with the use of lithium-pilocarpine except for the CON group.After the successful establishment of TLE models,all drugs were administered through gavage,and distilled water was given to rats in the CON and MOD groups for four weeks.The frequency and duration of seizures before and after treatment were recorded for the evaluation of the alleviation degree.Quantitative real-time polymerase chain reaction(qRT-PCR)was used to detect the expression levels of miR-146a-3p and miR-146a-5p.The expression levels of toll-like receptor 4(TLR4),interleukin-1 receptor-associated kinase 1(IRAK1),tumor necrosis factor(TNF)receptor-associated factor 6(TRAF6),TAK1-binding protein(TAB),nuclear factor-kappa B(NF-κB),and interleukin-1 beta(IL-1β)in hippocampus were tested by immunofluorescence assay.Correlation analysis between the above factors and expressions of miR-146a-3p and miR-146a-5p were performed separately.Results CHLGMLD decreased the frequency(P<0.05)and duration(P<0.01)of seizures in rats.CHLGMLD down-regulated the expression levels of miR-146a-5p and miR-146a-3p(P<0.05),and inhibited the expression levels of TLR4,IRAK1,TRAF6,TAB,NF-κB,and IL-1β(P<0.01).The correlation analysis revealed that the expression levels of TLR4,IRAK1,TRAF6,TAB,NF-κB,and IL-1β were positively correlated with the expression levels of miR-146a-3p and miR-146a-5p detected by qRT-PCR,respectively(P<0.01).Conclusion CHLGMLD can inhibite the TLR4 signaling pathway by lowering the expression levels of miR-146a-3p and miR-146a-5p to alleviate hippocampal dentate gyrus inflammation in TLE rats,thus relieving seizures.

Subicular pyramidal neurons gate drug resistance in temporal lobe epilepsy

OBJECTIVE To understand the underlying mechanisms of drug resistant temporal lobe epilepsy(TLE).METHODS In vivo and vitro electrophysiology,optogenetics and chemogenetics were used in a classic multi-drug resistant TLE model.RESULTS Subicular pyramidal neuron activity was not inhibited by the anti-epileptic drug phenytoin in drug resistant rats.This phenomenon was specific to the subiculum,but did not involve surrounding temporal lobe regions.Selective inhibition of subicular pyramidal neurons by both optogenetics and chemogenetics reversed drug resistance.In contrast,selective activation of subicular pyramidal neurons directly induced drug resistance in drug responsive rats.Furthermore,long-term low frequency stimulation at the subiculum,which is clinically feasible,inhibited the activity of subicular pyramidal neurons and reversed drug resistance.CONCLUSION Subicular pyramidal neurons might be a key ″ switch″ mediating drug resistance in TLE and represent a new potential target for more precise treatment of drug resistant TLE.

Association between serotonin transporter gene polymorphisms and non-lesional temporal lobe epilepsy in a Chinese Han population

Serotonin （5-hydroxytryptamine, 5-HT） influences the cortical and subcortical excitatory/inhibitory balance and participates in the pathophysiological processes of epilepsy. The serotonin transporter （5-HTT） is the most important factor in serotonin inactivation. We tested whether 5-HTT polymorphisms are involved in the pathogenesis of epilepsy in Chinese Han population. We did not find a significant difference in the frequencies of genotypes and alleles in the 5-HTT gene-linked poLymorphic region （5-H-I-FLPR） in patients with non-lesional temporal lobe epilepsy and normal controls （P〉 0.05）. Frequencies of the 5-H1-1- intron 2 variable number tandem repeat （5-HTTVNTR） 12/12 genotype and allele 12 were higher in the patients with non-lesional temporal lobe epilepsy than normal controls （P 〈 0.01）. The odds ratio of affecting non-lesional temporal lobe epilepsy was 1.435 （95% Cl, 1.096 1.880） in patients carrying allele 12 （P 〈 0.05）. Although the 5-HTTLPR may not be a genetic locus of non-lesional temporal lobe epilepsy in Chinese Hart population, allele 12 in the 5-HTTVNTR may correlate with non-lesional temporal lobe epilepsy. The Stin2.12 allele and 12/12 genotype could be predisposing to non-lesional temporal lobe epilepsy.

Remain Aggressive Behavior in Children with Temporal Lobe Epilepsy after Surgery

Behavioral problems have a high rate in patients with temporal lobe epilepsy but there have been few detailed reports about pediatric patients. We report two children with temporal lobe epilepsy who manifest behavior abnormality remaining after surgery. One child developed complex partial seizures at 10 years and 3 months of age caused by a left temporal ganglioglioma and manifested behavioral problems of lability, aggression, impulsivity and disinhibition. Seizures were relieved after temporal lobe resection at 10 years and 8 months of age but behavioral symptoms had been remained. The second child developed epilepsy at 3 years of age. He manifested similar behavioral problems at 7 years old. Seizures were relieved after temporal lobe resection at 13 years old but behavioral symptoms had been remained. Their courses suggested that aggressive behavior might be associated with not only temporal lesion but also other lesions such as frontal lobe or neural circuitry between both lobes. It is important to inform families of patients that behavioral disorders may not improve after epileptic surgery.

Early Detection of Temporal Lobe Epilepsy: Identification of Novel Candidate Genes and Potential Biomarkers Using Integrative Genomics Analysis

Currently afflicting more than 50 million people worldwide, epilepsy is the spectrum disorder characterizing seizures that occur without other plausible medical explanations. Temporal lobe epilepsy (TLE) is one of the most common forms of epilepsy. Current clinical methods;including MRI scans, EEG tests, and doctor visits;can take upwards of several months to confirm a TLE diagnosis;during this time, patients may experience additional seizures and are at an increased risk for other psychiatric disorders. The purpose of this study is to identify candidate genetic biomarkers to facilitate the earlier detection and diagnosis of TLE through gene-based testing (e.g., genomic heatmap analysis or genetic and/or microarray testing). It was hypothesized that potential biomarkers could be identified by analyzing genes that are normally significantly overexpressed in the temporal lobe relative to the gray matter. Statistical and functional analysis was performed on significantly overexpressed genes (≥3.000 fold change) in the gene expression profiles of four donors without epilepsy. The experimental-evidence-based STRING protein interactions analysis showed associations between genes found in DAVID keyword search and other genes facilitating network interconnectivity. After evaluation of the genes’ STRING enriched functions, changes in the expression of the genes CAMK2A, NPY, DLG4, MEF2C, and MAPK7 were concluded to be potential biomarkers for TLE, confirming the original hypothesis. Specifically, the identification of MEF2C and MAPK7 for this purpose is relatively novel in the fields of bioinformatics and neurogenetics. Future work includes investigating the utility of the candidate genes in real-world gene-based diagnostic methods.

The Relationship between Aggressiveness and Gender in Patients with Temporal Lobe Epilepsy

Purpose: To examine the impact of gender and social gender on the level and typology of interictal aggressiveness in patients with temporal lobe epilepsy. Material and Methods: 40 adult patients with Temporal Lobe Epilepsy (TLE) and 86 healthy individuals were included. The qualitative and quantitative aggressiveness assess- ment was made with Buss-Durkee Hostility Inventory. The gender role behavior was measured with Bem Sex Role Inventory. Results: Patients with TLE didn’t differ from healthy subjects on the total scores of motor and attitudinal hostility components, but scored higher on subscales “resentment” and “guilt”. The comparative gender analysis showed there were no phenomenological differences in people with TLE. Assault dominated in healthy male subjects, resentment—in healthy female subjects. The prevalence of feminine social gender type was significantly higher in people with TLE in comparison to healthy people (55% vs. 26%, p 0.01). In patients with TLE, the number of masculine traits positively correlated with indirect hostility subscale and attitudinal hostility component scores. In healthy subjects, the masculine traits positively correlated with assault.

Autophagy-related genes in mesial temporal lobe epilepsy:an integrated bioinformatics analysis

Background Autophagy plays essential roles in the development and pathogenesis of mesial temporal lobe epilepsy(mTLE).In this research,we aim to identify and validate the autophagy-related genes associated with mTLE through bioinformatics analysis and experimental validations.Methods We obtained the dataset GSE143272 and high-throughput sequencing results of mTLE from public data-bases.Potential differentially expressed autophagy-related genes related to mTLE were identified using R software.Subsequently,genomes pathway enrichment analysis,protein-protein interactions(PPIs),and the gene ontology(GO)enrichment were performed for the selected autophagy-related genes.The mRNA expression profiles of hub genes were then used to establish a least absolute shrinkage and selection operator(LASSO)model.Finally,seven hub candidate autophagy-related genes were confirmed in hippocampus using the lithium-pilocarpine chronic epilepsy model.Results A total of 40 differential expression genes(DEGs)among the core autophagy-related genes were identified.The analysis results of PPI revealed that interactions among these DEGs.KEGG pathway and GO analysis of selected candidate autophagy-related genes indicated that those enriched terms mainly focused on macroautophagy,regula-tion of autophagy,cellular response to extracellular stimulus and mitochondrion disassembly.The results suggested that SQSTM1,VEGFA,BNIP and WIPI2 were consistent with the bioinformatics analysis.The expression levels of SQSTM1 and VEGFA in epilepsy model samples were significantly higher than those in normal control,while BNIP and WIPI2 expression levels were notably decreased.The final hub gene-based LASSO regression model accurately predicted the occurrence of epilepsy(AUC=0.88).Conclusions Through bioinformatics analysis of public data,we identified 40 candidate autophagy-related genes associated with mTLE.SQSTM1,VEGFA,BNIP and WIPI2 may play significant roles in autophagy,influencing the onset and development of mTLE by regulating autophagy pathway.These findings deepen our understanding of mTLE,and may serve as sensitive and valuable indicators for the prognosis and diagnosis of this condition.

Low-frequency Stimulation at the Subiculum Prevents Extensive Secondary Epileptogenesis in Temporal Lobe Epilepsy

Secondary epileptogenesis is characterized by increased epileptic susceptibility and a tendency to generate epileptiform activities outside the primary focus.It is one of the major resultants of pharmacoresistance and failure of surgical outcomes in epilepsy,but still lacks effective treatments.Here,we aimed to test the effects of low-frequency stimulation(LFS)at the subiculum for secondary epileptogenesis in a mouse model.Here,secondary epileptogenesis was simulated at regions both contralateral and ipsilateral to the primary focus by applying successive kindling stimuli.Mice kindled at the right CA3 showed higher seizure susceptibilities at both the contralateral CA3 and the ipsilateral entorhinal cortex and had accelerated kindling processes compared with naive mice.LFS at the ipsilateral subiculum during the primary kindling progress at the right CA3 effectively prevented secondary epileptogenesis at both the contralateral CA3 and the ipsilateral entorhinal cortex,characterized by decreased seizure susceptibilities and a retarded kindling process at those secondary foci.Only application along with the primary epileptogenesis was effective.Notably,the effects of LFS on secondary epileptogenesis were associated with its inhibitory effect at the secondary focus through interfering with the enhancement of synaptic connections between the primary and secondary foci.These results imply that LFS at the subiculum is an effective preventive strategy for extensive secondary epileptogenesis in temporal lobe epilepsy and present the subiculum as a target with potential translational importance.

Anti-epileptic and Neuroprotective Effects of Ultra-low Dose NADPH Oxidase Inhibitor Dextromethorphan on Kainic Acid-induced Chronic Temporal Lobe Epilepsy in Rats

Neuroinflammation mediated by microglia and oxidative stress play pivotal roles in the development of chronic temporal lobe epilepsy(TLE).We postulated that kainic acid(KA)-Induced status epilepticus triggers microglia-dependent inflammation,leading to neuronal damage,a lowered seizure threshold,and the emergence of spontaneous recurrent seizures(SRS).Extensive evidence from our laboratory suggests that dextromethorphan(DM),even in ultra-low doses,has anti-inflammatory and neuroprotective effects in many animal models of neurodegenerative disease.Our results showed that administration of DM(10 ng/kg per day;subcutaneously via osmotic minipump for 4 weeks)significantly mitigated the residual effects of KA,including the frequency of SRS and seizure susceptibility.In addition,DM-treated rats showed improved cognitive function and reduced hippocampal neuronal loss.We found suppressed microglial activation-mediated neuroinflammation and decreased expression of hippocampal gp91^(phox) and p47^(phox) proteins in KA-induced chronic TLE rats.Notably,even after discontinuation of DM treatment,ultra-low doses of DM continued to confer long-term anti-seizure and neuroprotective effects,which were attributed to the inhibition of microglial NADPH oxidase 2 as revealed by mechanistic studies.