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.

[Clinical characteristics and genetic analysis of a case of infantile Schaaf-Yang syndrome due to a heterozygous variant of MAGEL2 gene].

OBJECTIVE: To explore the diagnosis, treatment and genetic analysis of an infant with Schaaf-Yang syndrome (SYS). METHODS: An infant suspected for SYS at the Hunan Provincial Children's Hospital on June 10, 2022 was subjected to trio-whole exome sequencing, and Sanger sequencing was used to verify the candidate variant. Structure of the wild-type and mutant proteins was constructed to analyze the potential hazard. RESULTS: The infant was found to harbor a heterozygous frameshifting variant of c.1908delG (p.R637Gfs*65) of the MAGEL2 gene, which was found in neither of his parents. The variant has not been recorded by the public databases, and no relevant literature was retrieved. As the result of the variant, the MAGEL2 protein only retained part of its proline domain, which may lead to destruction and/or down-regulation of its function. CONCLUSION: The c.1908delG (p.R637Gfs*65) variant of the MAGEL2 gene probably underlay the pathogenesis in this child. Combined with his clinical characteristics, the child was diagnosed with SYS. Above finding has also enriched the mutational spectrum of the MAGEL2 gene.

Cohen syndrome in two patients from China.

BACKGROUND: Cohen syndrome (CS; OMIM 216550) is a rare syndrome with evident clinical heterogeneity. The diverse phenotype comprises early-onset hypotonia and developmental delays, intellectual disabilities, microcephaly, hypermobile joints, neutropenia, myopia, and characteristic facial features. The disease is rarely reported. Vacuolar Protein Sorting 13 Homolog B (VPS13B; OMIM 607817) is the only causative gene of CS. METHODS: Blood samples sourced from both siblings and parents were sent to identify mutations by trio-WES, and changes in the patient's condition were understood through consultation data and follow-up. RESULTS: We reported two siblings affected by developmental delay, microcephaly, intellectual disability, and facial features. The siblings' WES detected compound heterozygous variants in the exon region of VPS13B (NM_017890): c.9337A>T and c.8551A>C. CONCLUSION: Two individuals were diagnosed with CS by genetic testing and clinical features. In addition, we conduct a brief review of the reports on the Chinese population with CS and reinforce the understanding of the correlation between genotype-phenotype.

Expansion of Clinical and Genetic Spectrum of DDX3X Neurodevelopmental Disorder in 23 Chinese Patients.

Aim: De novo DDX3X variants account for 1-3% of unexplained intellectual disability cases in females and very rarely in males. Yet, the clinical and genetic features of DDX3X neurodevelopmental disorder in the Chinese cohort have not been characterized. Method: A total of 23 Chinese patients (i.e., 22 female and 1 male) with 22 de novo DDX3X deleterious variants were detected among 2,317 probands with unexplained intellectual disability (ID) undertaking whole exome sequencing (WES). The age, sex, genetic data, feeding situation, growth, developmental conditions, and auxiliary examinations of the cohort were collected. The Chinese version of the Gesell Development Diagnosis Scale (GDDS-C) was used to evaluate neurodevelopment of DDX3X patients. The Social Communication Questionnaire (SCQ)-Lifetime version was applied as a primary screener to assess risk for autism spectrum disorder (ASD). Result: A total of 17 DDX3X variants were novel and 22 were de novo. Missense variants overall were only slightly more common than loss-of-function variants and were mainly located in two functional subdomains. The average age of this cohort was 2.67 (±1.42) years old. The overlapping phenotypic spectrum between this cohort and previously described reports includes intellectual disability (23/23, 100%) with varying degrees of severity, muscle tone abnormalities (17/23, 73.9%), feeding difficulties (13/23, 56.5%), ophthalmologic problems (11/23, 47.8%), and seizures (6/23, 26.1%). A total of 15 individuals had notable brain anatomical disruption (15/23, 65.2%), including lateral ventricle enlargement, corpus callosum abnormalities, and delayed myelination. Furthermore, 9 patients showed abnormal electroencephalogram results (9/23, 39.1%). Hypothyroidism was first noted as a novel clinical feature (6/23, 26.1%). The five primary neurodevelopmental domains of GDDS-C in 21 patients were impaired severely, and 13 individuals were above the "at-risk" threshold for ASD. Interpretation: Although a certain degree of phenotypic overlap with previously reported cohorts, our study described the phenotypic and variation spectrum of 23 additional individuals carrying DDX3X variants in the Chinese population, adding hypothyroidism as a novel finding. We confirmed the importance of DDX3X as a pathogenic gene in unexplained intellectual disability, supporting the necessity of the application of WES in patients with unexplained intellectual disability.

Radiosensitizer EXO-miR-197-3p Inhibits Nasopharyngeal Carcinoma Progression and Radioresistance by Regulating the AKT/mTOR Axis and HSPA5-mediated Autophagy.

The biological functions of exosomes and microRNAs (miRs) in nasopharyngeal carcinoma (NPC) remain largely unexplored. Here, miR-197-3p was screened and identified, and whose level was reduced in serum and exosomes of patients with NPC. MiR-197-3p might be a good diagnostic and prognostic indicator. Our data showed that miR-197-3p expression was closely related to radioresistance, apoptosis, proliferation, migration, and survival of NPC. Inhibition of miR-197-3p expression in vitro could promote the proliferation and migration of NPC cells, while promotion of miR-197-3p expression in vivo could significantly inhibit the growth and enhance the radiosensitivity of NPC cells. From the perspective of mechanism, miR-197-3p could inhibit AKT/mTOR phosphorylation activation, inhibit an activated pathway of AKT/mTOR, target Heat Shock 70-kDa Protein 5(HSPA5) related to endoplasmic reticulum homeostasis, inhibit HSPA5-mediated autophagy, and reverse the radioresistance of NPC. Interestingly, exosomal miR-197-3p (EXO-miR-197-3p) reduced the proliferation and migration potential of NPC cells in vitro, and tumor growth and radioresistance of NPC cells in vivo. EXO-miR-197-3p inhibited NPC progression and radioresistance by regulating AKT/mTOR phosphorylation activation and HSPA5-mediated autophagy. In conclusion, our results highlight the potential of EXO-miR-197-3p as an effective radiosensitizer and therapeutic agent for refractory NPC.

Genetic screening in patients of Meige syndrome and blepharospasm.

OBJECTIVE: Meige syndrome (MS) is cranial dystonia, including bilateral eyelid spasms (blepharospasm; BSP) and involuntary movements of the jaw muscles (oromandibular dystonia; OMD). Up to now, the pathogenic genes of MS and BSP are still unclear. METHODS: We performed Sanger sequencing of GNAL, TOR1A, TOR2A, THAP1, and REEP4 exons on 78 patients, including 53 BSP and 25 MS and 96 healthy controls. RESULTS: c.845G > C[R282P] of TOR1A, c.629delC[p.Gly210AlafsTer60] of TOR2A, c.1322A > G[N441S] of GNAL, c.446G > A[R149Q], and c.649C > T[R217C] of REEP4 were identified and predicated as deleterious probably damaging variants. Three potential alterations of splicing variants of TOR1A and TOR2A were identified in patients. The frequencies of TOR1A rs1435566780 and THAP1 rs545930392 were higher in patients than in controls. CONCLUSIONS: TOR1A rs1435566780 (c.*16G > C(G > A)) and THAP1 rs545930392 (c.192G > A[K64K]) may contribute to the etiology of MS and BSP. Other identified rare mutations predicted as deleterious probably damaging need further confirmation. Larger MS and BSP cohorts and functional studies will need to be performed further to elucidate the association between these genes and the diseases.

The second DDOST-CDG patient with lactose intolerance, developmental delay, and situs inversus totalis.

Congenital disorders of glycosylation (CDGs) are inherited metabolic diseases affecting protein and lipid glycosylation. DDOST-CDG is a rare, newly identified type of CDGs, with only one case reported so far. In this study, we report a Chinese patient with a homozygous pathogenic variant in DDOST (c.1187G>A) and who presented with feeding difficulty, lactose intolerance, facial dysmorphism, failure to thrive, strabismus, high myopia, astigmatism, hypotonia, developmental delay and situs inversus totalis. Serum transferrin isoelectrofocusing demonstrated defective glycosylation in our patient. This finding further identifies DDOST as a genetic cause of CDGs and expands the clinical phenotype of DDOST-CDG.

Extracranial 125I Seed Implantation Allows Non-invasive Stereotactic Radioablation of Hippocampal Adult Neurogenesis in Guinea Pigs.

Adult hippocampal neurogenesis (AHN) is important for multiple cognitive functions. We sort to establish a minimal or non-invasive radiation approach to ablate AHN using guinea pigs as an animal model. 125I seeds with different radiation dosages (1.0, 0.8, 0.6, 0.3 mCi) were implanted unilaterally between the scalp and skull above the temporal lobe for 30 and 60 days, with the radiation effect on proliferating cells, immature neurons, and mature neurons in the hippocampal formation determined by assessment of immunolabeled (+) cells for Ki67, doublecortin (DCX), and neuron-specific nuclear antigen (NeuN), as well as Nissl stain cells. Spatially, the ablation effect of radiation occurred across the entire rostrocaudal and largely the dorsoventral dimensions of the hippocampus, evidenced by a loss of DCX+ cells in the subgranular zone (SGZ) of dentate gyrus (DG) in the ipsilateral relative to contralateral hemispheres in reference to the 125I seed implant. Quantitatively, Ki67+ and DCX+ cells at the SGZ in the dorsal hippocampus were reduced in all dosage groups at the two surviving time points, more significant in the ipsilateral than contralateral sides, relative to sham controls. NeuN+ neurons and Nissl-stained cells were reduced in the granule cell layer of DG and the stratum pyramidale of CA1 in the groups with 0.6-mCi radiation for 60 days and 1.0 mCi for 30 and 60 days. Minimal cranial trauma was observed in the groups with 0.3- 1.0-mCi radiation at 60 days. These results suggest that extracranial radiation with 125I seed implantation can be used to deplete HAN in a radioactivity-, duration-, and space-controllable manner, with a "non-invasive" stereotactic ablation achievable by using 125I seeds with relatively low radioactivity dosages.

Reproduction-Associated Hormones and Adult Hippocampal Neurogenesis.

The levels of reproduction-associated hormones in females, such as estrogen, progesterone, prolactin, and oxytocin, change dramatically during pregnancy and postpartum. Reproduction-associated hormones can affect adult hippocampal neurogenesis (AHN), thereby regulating mothers' behavior after delivery. In this review, we first briefly introduce the overall functional significance of AHN and the methods commonly used to explore this front. Then, we attempt to reconcile the changes of reproduction-associated hormones during pregnancy. We further update the findings on how reproduction-related hormones influence adult hippocampal neurogenesis. This review is aimed at emphasizing a potential role of AHN in reproduction-related brain plasticity and its neurobiological relevance to motherhood behavior.

SCN1B and SCN2B gene variants analysis in dravet syndrome patients: Analysis of 22 cases.

Previous research identified SCN1B variants in some cases of Dravet syndrome (DS). We investigated whether SCN1B and SCN2B variants are commonly happened in DS patients without SCN1A variants. A total of 22 DS patients without SCN1A variants and 100 healthy controls were enrolled in this genetic study. DNA from DS patients was sequenced by Sanger method in whole exons of SCN1B and SCN2B genes. We identified two exon variants (c.351C>T, p.G117G and c.467C>T, p.T156M), which were present both in 1000 egenomes database and in healthy controls with a frequency of 0.54% and 4%, 0.06% and 0%, respectively. Additionally, eight intron or 3 prime UTR variants showing benign clinical significance have also been identified. Our results suggest that variants of SCN1B and SCN2B may not be common causes of DS according to our data. Further large sample-size cohort studies are needed to confirm our conclusion.

Common variants of APOE are associated with anti-epileptic drugs resistance in Han Chinese patients.

Purpose/aim of the study: Apolipoprotein E (APOE) has been implicated as one of the susceptibility genes for some subtypes of epilepsy and may be related to anti-epileptic drugs resistance. The purpose of this study was to investigate the possible association between APOE variants and the anti-epileptic drugs resistance in Chinese population. MATERIALS AND METHODS: APOE gene rs429358 and rs7412 variants were genotyped for ϵ2, ϵ3, ϵ4 alleles using amplification refractory mutation system in 480 subjects including 207 anti-epileptic drugs-resistant patients and 273 drug-responsive patients. RESULTS: We found that the frequency of APOE gene rs429358 C allele in the drug resistant patients is higher than that in the drug-responsive patients (14.98% vs. 10.1%, OR = 1.25[1.02 - 1.52], p = 0.017). Moreover, according to the two variants, we analyzed the distributions of -ϵ4 and +ϵ4 alleles of APOE gene and found that there were higher frequencies of +ϵ4 allele in drug-resistant epileptic patients than that in drug-responsive patients (31.8% vs. 13.2%, OR = 1.15[1.05 - 1.25], p = 0.002). CONCLUSIONS: Our study demonstrated that APOE rs429358 variant C allele and ϵ4 allele were associated with the anti-epileptic drugs resistance in Han Chinese patients.

Neurological complications and risk factors of cardiopulmonary failure of EV-A71-related hand, foot and mouth disease.

From 2010 to 2012, large outbreaks of EV-A71-related- hand foot and mouth disease (HFMD) occurred annually in China. Some cases had neurological complications and were closely associated with fatal cardiopulmonary collapse, but not all children with central nervous system (CNS) involvement demonstrated a poor prognosis. To identify which patients and which neurological complications are more likely to progress to cardiopulmonary failure, we retrospectively studied 1,125 paediatric inpatients diagnosed with EV-A71-related HFMD in Hunan province, including 1,017 cases with CNS involvement. These patients were divided into cardiopulmonary failure (976 people) group and group without cardiopulmonary failure (149 people). A logistic regression analysis was used to compare the clinical symptoms, laboratory test results, and neurological complications between these two groups. The most significant risk factors included young age, fever duration ≥3 days, coma, limb weakness, drowsiness and ANS involvement. Patients with brainstem encephalitis and more CNS-involved regions were more likely to progress to cardiopulmonary failure. These findings can help front-line clinicians rapidly and accurately determine patient prognosis, thus rationally distributing the limited medical resources and implementing interventions as early as possible.

[Negative association of FGA gene 128C/G polymorphism with cerebral infarction and its effect on plasma fibrinogen in Hunan Hans].

OBJECTIVE: To investigate the relationship of FGA gene 128C/G polymorphism and cerebral infarction (CI) and evaluate the effect of FGA-128C/G polymorphism on plasma fibrinogen in Hunan Hans. METHODS: FGA-128C/G polymorphism was detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing in 194 CI patients and 114 healthy controls. RESULTS: There were CG and CC genotypes in the FGA-128C/G locus. No GG genotype was observed in Hunan Hans. There was no significant difference in genotype and allele frequencies between the controls and CI group (P> 0.05), and statistically significant difference was not found in fibrinogen (Fg) level between the CG and CC genotypes (P>0.05). After analyzing blood plasma Fg using the influencing factor multiple regression analysis, it was shown that the Fg level had no relationship with the FGA-128C/G genotype, but it increased with age. And the Fg level in males was higher than that in females. CONCLUSION: There was FGA gene 128C/G polymorphism in the Hunan Han population. There was no association of this polymorphism with the increased Fg level of CI patient in the population. FGA-128C/G might not be the predisposing gene of CI in Hunan Han population. The age and sex were the major factors affecting the plasma Fg level in this population.