Objective: The age-related changes in the resting-state networks (RSNs) exhibited temporally specific patterns in humans, and humans and rhesus monkeys have similar RSNs. We hypothesized that the RSNs in rhesus monkeys experienced similar developmental patterns as humans. Methods: We acquired resting-state fMRI data from 62 rhesus monkeys, which were divided into childhood, adolescence, and early adulthood groups. Group independent component analysis (ICA) was used to identify monkey RSNs. We detected the between-group differences in the RSNs and static, dynamic, and effective functional network connections (FNCs) using one-way variance analysis (ANOVA) and post-hoc analysis. Results: Eight rhesus RSNs were identified, including cerebellum (CN), left and right lateral visual (LVN and RVN), posterior default mode (pDMN), visuospatial (VSN), frontal (FN), salience (SN), and sensorimotor networks (SMN). In internal connections, the CN, SN, FN, and SMN mainly matured in early adulthood. The static FNCs associated with FN, SN, pDMN primarily experienced fast descending slow ascending type (U-shaped) developmental patterns for maturation, and the dynamic FNCs related to pDMN (RVN, CN, and SMN) and SMN (CN) were mature in early adulthood. The effective FNC results showed that the pDMN and VSN (stimulated), SN (inhibited), and FN (first inhibited then stimulated) chiefly matured in early adulthood. Conclusion: We identified eight monkey RSNs, which exhibited similar development patterns as humans. All the RSNs and FNCs in monkeys were not widely changed but fine-tuned. Our study clarified that the progressive synchronization, exploration, and regulation of cognitive RSNs within the pDMN, FN, SN, and VSN denoted potential maturation of the RSNs throughout development. We confirmed the development patterns of RSNs and FNCs would support the use of monkeys as a best animal model for human brain function.

Purpose: The aim of this study was to investigate how human immunodeficiency virus (HIV) affects brain development in adolescents, what are susceptible brain regions, and how these brain structural changes correlate with cognitive abilities. Methods: We used structural magnetic resonance imaging to examine gray matter volume and cortical thickness in 16 HIV-infected children (mean age = 13.63 years) and 25 HIV-exposed uninfected children (mean age = 13.32 years), 12 of them were subjected to a 1-year repetitive magnetic resonance scan of the brain. Five neurocognitive tests were performed on each subject to assess cognitive performance in different areas. Results: Cross-sectional studies showed that the gray matter volume of HIV-infected children was widely reduced (mainly in the bilateral frontal, temporal, and insular regions, and cerebellum). The changes in cortical thickness were mainly due to thinning of the right temporal lobe and thickening of the left occipital lobe. Longitudinal studies showed that the gray matter volume reduction of HIV-infected children after 1 year mainly occurs in the advanced functional area of the right prefrontal, parietal lobe and the motor area, cortical thinning of brain regions were sensorimotor cortex and the limbic system. The gray matter volume of the bilateral cerebellum was positively correlated with the performance of the Wisconsin Card Sorting Test, while the cortical thickness of the right dorsolateral prefrontal cortex was negatively correlated with this test. Conclusion: This study found that HIV-infected pubertal children showed a delayed cortical maturation with atrophy. This abnormal pattern of cortical development may be the structural basis for cognitive impairment in HIV-infected children.

Abstract Introduction High glucose levels are associated with cognitive impairment and total hippocampal volume reductions. However, the effects of the blood glucose level on hippocampal subfield volumes remain unclear, especially in the prediabetes stage. Methods Sixty participants were enrolled in this cross‐sectional study and were divided into the nondiabetes, prediabetes, and diabetes groups according to their medical history and A1c level. A full battery of neuropsychological tests was used to assess the global cognition, executive function, attention, verbal fluency, working memory, immediate memory, and delayed memory. FreeSurfer 6.0 was used for the hippocampus parcellation. Hippocampal subfield volumes were adjusted by intracranial volume. Analyses of covariance, multiple linear regression, and partial correlation analysis were used to explore the relationship between A1c level, cognitive function, and hippocampal subfields volume, in which age, sex, education years, body mass index, history of hypertension, level of cholesterol, and the presence of ApoE4‐positive status were adjusted. Results Significant differences in the total left hippocampal volume (p = 0.046) and left hippocampal tail volume (p = 0.014) were noted among three groups. Significant correlation was identified between the A1c level and the volume of left hippocampal tail (r = −0.334, p = 0.009) after adjusting all the covariants. Increased A1c level was significantly associated with executive dysfunction, as assessed by trail making test B (R = 0.503, p = 0.0016) and Stroop test C (R = 0.506, p = 0.001). Conclusions Our results support that the left hippocampal tail volume may be served as an early marker of diabetes‐related brain damage, associated with executive dysfunction. Clinicians should pay closer attention to adults in the prediabetes stage to prevent later cognitive impairment.

OBJECTIVE:This study aimed to investigate the role of glucagon-like peptide-1 (GLP-1)/GLP-1 receptor(R) signaling in the regulation of seizure susceptibility and to explore the potential mechanism in rats.METHODS:Hyperthermia-induced seizures in SD rats were generated using hot bath methods, and seizure severity was measured according to Racine scores and electroencephalogram (EEG). Protein levels of GLP-1 and GLP-1R in the brain tissues of rats were evaluated through ELISA, western blot analysis, and immunohistochemistry to explore the possible roles of each in FS. Neuronal excitability, spontaneous inhibitory postsynaptic currents (sIPSCs) and transient receptor potential cation channel subfamily V member 1(TRPV1) currents were tested using the patch-clamp method in cultured hippocampal neurons.RESULT:Significant decreases in the levels of GLP-1 and GLP-1R were observed in the hippocampi of rats compared to those in the control group. Furthermore, treatment with the GLP-1R pharmacological inhibitor exendin9-39 increased hyperthermia- induced seizure severity in rats and promoted neuronal firing activity in cultured neurons. Importantly, exendin9-39 and GLP-1R knockdown decreased the amplitude and frequency of sIPSCs in cultured neurons. In addition, GLP-1R knockdown elevated downstream TRPV1 expression and promoted capsaicin-induced TRPV1 function, which may regulate inhibitory neurotransmission to affect seizure susceptibility.CONCLUSION:The present study suggests that inhibition of GLP-1R signaling promotes seizure activity, which plays a key role in the pathogenesis of FS.

Objective To investigate the level of interleukin-6 (IL-6) and the effect of valproic acid(VPA) administration on IL-6 promoter methylation, further to explore the epigenetic mechanism in febrile seizures. Methods Sprague-Dawley (SD) rats (21 day) were randomly divided into control group (n=12) and febrile seizure (FS) group (n=12), and seizures were generated using hot bath methods and evaluated by racine score and electroencephalogram (EEG). The IL-6 protein and mRNA levels were detected using ELISA and quantitative reverse transcription polymerase chain reaction (qRT-PCR), respectively.Rat C6 cell line was cultured and randomly divided into control, VPA(0.2 mol/L), hyperthermia(43.5 ℃, 1 h), hyperthermia (43.5 ℃, 1 h)+VPA (0.2 mol/L) groups.The methylation status of IL-6 promoter in FS rats and the effect of VPA on IL-6 methylation in C6 cell line were examined by bisulfite sequencing polymerase chain reaction (BSP) to determine the epigenetic regulation of IL-6 level in FS. Results Racine score and EEG results showed that the frequency and amplitude of neuronal discharge increased after hot water bath in rats, and the latency of convulsion was shorter.The expression levels of IL-6 mRNA and protein were significantly increased in Fs group compared with those in control group(mRNA: Control: 0.98±0.34; FS: 2.85±0.39, P<0.05; Protein: Control: (2 824.33±169.20)pg/ml; FS: (3 514.58±86.4)pg/ml, P<0.01). The methylation of IL-6 promoter in FS group (84% (21/25)) was lower than that in control group (100% (25/25)) (P<0.05). A significant increase in methylation of IL-6 promoter was observed in C6 cell line from VPA combined with hyperthermia (96% (24/25)) but no change was showed in that from VPA alone (100% (25/25)) compared with that from control(100% (25/25)). Conclusion IL-6 level is up-regulated in FS rats, and the hypomethylation or demethylation of the IL-6 promoter region might increase the IL-6 level.VPA administration can elevate its methylation level, which provides a strong experimental basis for the future study of the epigenetic mechanism in FS. Key words: Febrile seizures; Interleukin-6; DNA methylation; Valproic acid; Bisulfite sequencingpolymerase chain reaction

“Asymptomatic” carotid artery stenosis (aCAS) patients usually have cognitive impairment in the domains of executive, psychomotor speed, and memory function. However, the pathophysiology of this impairment in aCAS patients is still unclear. In this study, amplitude of low-frequency fluctuation (ALFF) method was used based on resting-state blood oxygenation level dependent (BOLD) signals, to investigate local brain activity in 19 aCAS patients and 24 healthy controls, aimed to explore this pathophysiology mechanism. We analyzed this intrinsic activity in four individual frequency bands: Slow-2 (0.198–0.25 Hz), Slow-3 (0.073–0.198 Hz), Slow-4 (0.027–0.073 Hz), and Slow-5 (0.01–0.027 Hz). The aCAS-related ALFF changes were mainly distributed in (1) cortical midline structure, including bilateral dorsomedial prefrontal (dmPFC), cingulate cortex (CC) and precuneus (PCu); (2) hippocampus and its adjacent structures, including bilateral hippocampus, thalamus and medial temporal regions. We found these spatial patterns were frequency-dependent. Significant interaction between frequency and group was found distributed in left putamen, triangle part of inferior temporal and bilateral precentral/postcentral gyrus when Slow-4 and Slow-5 were considered. The delay recall ability of aCAS patient was significantly positive correlated to the mean ALFF in dmPFC within Slow-4 band and the mean ALFF in the bilateral hippocampus within Slow-3 band, respectively. We also found the Montreal Cognitive Assessme score of aCAS patient was significantly positive correlated to the mean ALFF in right fusiform and parahippocampus within Slow-3 band. Furthermore, we built the automatic diagnosis and prediction models based on support vector machine (SVM) and back propagation neural network (BPNN), respectively. Both two types of models could achieve relatively competent performance, which meant the frequency-dependent changes in ALFF could not only reveal the pathophysiology mechanism of cognitive impairment of aCAS, but also could be used as neuroimaging marker in the analysis of cognition impairment for aCAS patients.

Carotid artery stenosis without transient ischemic attack (TIA) or stroke is considered as "asymptomatic." However, recent studies have demonstrated that these asymptomatic carotid artery stenosis (aCAS) patients had cognitive impairment in tests of executive function, psychomotor speed, and memory, indicating that "asymptomatic" carotid stenosis may not be truly asymptomatic. In this study, when 19 aCAS patients compared with 24 healthy controls, aCAS patients showed significantly poorer performance on global cognition, memory, and executive function. By utilizing an integrated MRI including pulsed arterial spin labeling (pASL) MRI, Proton MR Spectroscopy (MRS), and resting-state functional MRI (R-fMRI), we also found that aCAS patients suffered decreased cerebral blood flow (CBF) mainly in the Left Frontal Gyrus and had decreased NAA/Cr ratio in the left hippocampus and decreased connectivity to the posterior cingulate cortex (PCC) in the anterior part of default mode network (DMN).

Epigenetic modifications including histone modifications are associated with seizure development and epileptogenesis; however, its underlying mechanism remains to be elucidated. Dipeptidyl peptidase 4 (DPP4) and IL6 are identified as febrile seizure (FS)-related genes using gene microarray analysis in hyperthermia prone (HP) rats. This purpose of the study focused on exploring whether epigenetic modifications marker histone H3 lysine 27 trimethylation (H3K27me3)-regulated DPP4 and IL6 expression further affected seizures development. Herein, we reported broad between-group differences in the global levels of H3K27me3 with increased seizure severity in vivo. Using chromatin immunoprecipitation (ChIP), we identified markedly decreased H3K27me3 enrichment at their promoters of DPP4 and IL6 in vivo. We further showed that hyperthermia significantly decreased protein levels of H3K27me3, increased mRNA levels of DPP4 and IL6 by decreasing H3K27me3 enrichment at their promoters of DPP4 and IL6 in vitro. Importantly, H3K27me3 loss via enhancer of zeste homolog 2 (EZH2) knockdown promoted expression of DPP4 and IL6 via the same mechanism in vitro. EZH2 knockdown also increased neuronal firing frequency in vitro and FS susceptibility in vivo companied with upregulation expression of DPP4 and IL6. Taken together, our study provided the first evidence that hyperthermia-induced decreased of H3K27me3 promoted seizure susceptibility via regulating the expression pattern of DPP4 and IL6. These findings suggested that the methylation level of H3K27me3 might be a key regulator of seizure susceptibility.

OBJECTIVE:Febrile seizures (FS) are the most common neurological disease in infancy and early childhood, it can lead to metabolic changes and have long-term health implications. Aim of this study was to investigate the long-term effects of FS on metabolism.METHODS:We measured certain metabolic parameters in hyperthermia-prone (HP) rats, which were developed using a selective breeding process and showed a lower seizure threshold than wild-type (WT) rats. Body weight, body length, abdominal circumference and the levels of fasting blood glucose, serum triglyceride, and total cholesterol concentrations were analyzed. The mRNA expression of genes involved in glucose and lipid metabolism was determined by qPCR and the histone methylation level in the liver was determined by western blot.RESULTS:We found that the body weight of the HP rats was significantly lower than that of the WT rats. Similarly, the fasting blood glucose and serum triglyceride levels were lower in the HP group compared with the WT group. These changes were accompanied by increased mRNA expression of genes such as phosphoenolpyruvate carboxykinase (PEPCK) and carnitine palmitoyl transferase-1 (CPT-1), but not peroxisome proliferator-activated receptor α (PPARα). We also found tri-methylation of histone 3 at Lys9 and Lys27 was decreased in the HP group.CONCLUSIONS:These data may suggest an underlying mechanism by which FS have a long-term effect on energy metabolism via histone methylation.