Genistein prevents the decrease in ganglioside levels induced by amyloid-beta in the frontal cortex of rats.

OBJECTIVES: In this study, an in vivo model of Aß toxicity was used to investigate the effects of this peptide and the treatment with genistein on the lipid composition (gangliosides, phospholipids and cholesterol) in the frontal cortex of rats. METHODS: Male Wistar rats received bilateral intracerebroventricular infusions of Aß1-42 (2 nmol) and genistein 10 mg/kg orally for 10 days. Frontal cortex was homogenized with chloroform:methanol for lipid extraction and ganglioside, phospholipid and cholesterol levels were evaluated. RESULTS: The Aß-infused animals showed a significant decrease in ganglioside concentration and relative reduction of GD1b and GQ1b species. Treatment with genistein prevented the decrease in ganglioside levels. Phospholipid and cholesterol contents did not show significant differences. DISCUSSION: Considering the roles of gangliosides on neuronal function, findings described here can contribute to the knowledge of the potential neuroprotective mechanisms of genistein against Aß-induced alterations in the frontal cortex of rats and provide a novel view in the multifaceted scenario associated with its beneficial effects.

Dimensional Changes in Lipid Rafts from Human Brain Cortex Associated to Development of Alzheimer's Disease. Predictions from an Agent-Based Mathematical Model.

Alzheimer's disease (AD) is a neurodegenerative disease caused by abnormal functioning of critical physiological processes in nerve cells and aberrant accumulation of protein aggregates in the brain. The initial cause remains elusive-the only unquestionable risk factor for the most frequent variant of the disease is age. Lipid rafts are microdomains present in nerve cell membranes and they are known to play a significant role in the generation of hallmark proteinopathies associated to AD, namely senile plaques, formed by aggregates of amyloid ß peptides. Recent studies have demonstrated that human brain cortex lipid rafts are altered during early neuropathological phases of AD as defined by Braak and Braak staging. The lipid composition and physical properties of these domains appear altered even before clinical symptoms are detected. Here, we use a coarse grain molecular dynamics mathematical model to predict the dimensional evolution of these domains using the experimental data reported by our group in human frontal cortex. The model predicts significant size and frequency changes which are detectable at the earliest neuropathological stage (ADI/II) of Alzheimer's disease. Simulations reveal a lower number and a larger size in lipid rafts from ADV/VI, the most advanced stage of AD. Paralleling these changes, the predictions also indicate that non-rafts domains undergo simultaneous alterations in membrane peroxidability, which support a link between oxidative stress and AD progression. These synergistic changes in lipid rafts dimensions and non-rafts peroxidability are likely to become part of a positive feedback loop linked to an irreversible amyloid burden and neuronal death during the evolution of AD neuropathology.

Amyloid pathology and synaptic loss in pathological aging.

Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive memory dysfunction and cognitive decline. Pathological aging (PA) describes patients who are amyloid-positive but cognitively unimpaired at time of death. Both AD and PA contain amyloid plaques dominated by amyloid ß (Aß) peptides. In this study, we investigated and compared synaptic protein levels, amyloid plaque load, and Aß peptide patterns between AD and PA. Two cohorts of post-mortem brain tissue were investigated. In the first, consisting of controls, PA, AD, and familial AD (FAD) individuals, synaptic proteins extracted with tris(hydroxymethyl)aminomethane-buffered saline (TBS) were analyzed. In the second, consisting of tissue from AD and PA patients from three different regions (occipital lobe, frontal lobe, and cerebellum), a two-step extraction was performed. Five synaptic proteins were extracted using TBS, and from the remaining portion Aß peptides were extracted using formic acid. Subsequently, immunoprecipitation with several antibodies targeting different proteins/peptides was performed for both fractions, which were subsequently analyzed by mass spectrometry. The levels of synaptic proteins were lower in AD (and FAD) compared with PA (and controls), confirming synaptic loss in AD patients. The amyloid plaque load was increased in AD compared with PA, and the relative amount of Aß40 was higher in AD while for Aß42 it was higher in PA. In AD loss of synaptic function was associated with increased plaque load and increased amounts of Aß40 compared with PA cases, suggesting that synaptic function is preserved in PA cases even in the presence of Aß.

High-Throughput Profiling of Proteome and Posttranslational Modifications by 16-Plex TMT Labeling and Mass Spectrometry.

Mass spectrometry (MS)-based proteomic profiling of whole proteome and protein posttranslational modifications (PTMs) is a powerful technology to measure the dynamics of proteome with high throughput and deep coverage. The reproducibility of quantification benefits not only from the fascinating developments in high-performance liquid chromatography (LC) and high-resolution MS with enhanced scan rates but also from the invention of multiplexed isotopic labeling strategies, such as the tandem mass tags (TMT). In this chapter, we introduce a 16-plex TMT-LC/LC-MS/MS protocol for proteomic profiling of biological and clinical samples. The protocol includes protein extraction, enzymatic digestion, PTM peptide enrichment, TMT labeling, and two-dimensional reverse-phase liquid chromatography fractionation coupled with tandem mass spectrometry (MS/MS) analysis, followed by computational data processing. In general, more than 10,000 proteins and tens of thousands of PTM sites (e.g., phosphorylation and ubiquitination) can be confidently quantified. This protocol provides a general protein measurement tool, enabling the dissection of protein dysregulation in any biological samples and human diseases.

AIF3 splicing switch triggers neurodegeneration.

BACKGROUND: Apoptosis-inducing factor (AIF), as a mitochondrial flavoprotein, plays a fundamental role in mitochondrial bioenergetics that is critical for cell survival and also mediates caspase-independent cell death once it is released from mitochondria and translocated to the nucleus under ischemic stroke or neurodegenerative diseases. Although alternative splicing regulation of AIF has been implicated, it remains unknown which AIF splicing isoform will be induced under pathological conditions and how it impacts mitochondrial functions and neurodegeneration in adult brain. METHODS: AIF splicing induction in brain was determined by multiple approaches including 5' RACE, Sanger sequencing, splicing-specific PCR assay and bottom-up proteomic analysis. The role of AIF splicing in mitochondria and neurodegeneration was determined by its biochemical properties, cell death analysis, morphological and functional alterations and animal behavior. Three animal models, including loss-of-function harlequin model, gain-of-function AIF3 knockin model and conditional inducible AIF splicing model established using either Cre-loxp recombination or CRISPR/Cas9 techniques, were applied to explore underlying mechanisms of AIF splicing-induced neurodegeneration. RESULTS: We identified a nature splicing AIF isoform lacking exons 2 and 3 named as AIF3. AIF3 was undetectable under physiological conditions but its expression was increased in mouse and human postmortem brain after stroke. AIF3 splicing in mouse brain caused enlarged ventricles and severe neurodegeneration in the forebrain regions. These AIF3 splicing mice died 2-4 months after birth. AIF3 splicing-triggered neurodegeneration involves both mitochondrial dysfunction and AIF3 nuclear translocation. We showed that AIF3 inhibited NADH oxidase activity, ATP production, oxygen consumption, and mitochondrial biogenesis. In addition, expression of AIF3 significantly increased chromatin condensation and nuclear shrinkage leading to neuronal cell death. However, loss-of-AIF alone in harlequin or gain-of-AIF3 alone in AIF3 knockin mice did not cause robust neurodegeneration as that observed in AIF3 splicing mice. CONCLUSIONS: We identified AIF3 as a disease-inducible isoform and established AIF3 splicing mouse model. The molecular mechanism underlying AIF3 splicing-induced neurodegeneration involves mitochondrial dysfunction and AIF3 nuclear translocation resulting from the synergistic effect of loss-of-AIF and gain-of-AIF3. Our study provides a valuable tool to understand the role of AIF3 splicing in brain and a potential therapeutic target to prevent/delay the progress of neurodegenerative diseases.

Stay or go? Neuronal activity in medial frontal cortex during a voluntary tactile preference task in head-fixed mice.

The decision to move is influenced by sensory, attentional, and motivational cues. One such cue is the quality of the tactile input, with noxious or unpleasant sensations causing an animal to move away from the cue. Processing of painful and unpleasant sensation in the cortex involves multiple brain regions, although the specific role of the brain areas involved in voluntary, rather than reflexive movement away from unpleasant stimuli is not well understood. Here, we focused on the medial subdivision of secondary motor cortex, which is proposed to link sensory and contextual cues to motor action, and tested its role in controlling voluntary movement in the context of an aversive tactile cue. We designed a novel, 3D-printed tactile platform consisting of innocuous (grid) and mildly noxious (spiked) surfaces (50:50 % of total area), which enabled monitoring neuronal activity in the medial frontal cortex by two-photon imaging during a sensory preference task in head-fixed mice. We found that freely moving mice spent significantly less time on a spiked-surface, and that this preference was eliminated by administration of a local anesthetic. At the neuronal level, individual neurons were differentially modulated specific to the tactile surface encountered. At the population level, the neuronal activity was analyzed in relation to the events where mice chose to "stop-on" or "go-from" a specific tactile surface and when they "switched" surfaces without stopping. Notably, each of these three scenarios showed population activity that differed significantly between the grid and spiked tactile surfaces. Collectively, these data provide evidence that tactile quality is encoded within medial frontal cortex. The task pioneered in this study provides a valuable tool to better evaluate mouse models of nociception and pain, using a voluntary task that allows simultaneous recording of preference and choice.

[Correlation between altered levels of neurotransmitters in the frontal lobe and hippocampus and behavioral abnormalities in a Clockdelta19 mutant mice modeling bipolar manic disorder].

OBJECTIVE: To explore the correlation between altered levels of neurotransmitters in the frontal lobe and hippocampus and behavioral abnormalities in a Clockdelta19 variant mice modeling bipolar disorder manic disorder. METHODS: Open field test and Elevated plus-maze test were carried out on the Clockdelta19 mutant and wild-type control groups. The frontal lobe and hippocampus of Clockdelta19 mutant mice and controls were dissected, and neurotransmitters in tissue extracts were analyzed by high-performance liquid chromatography and mass spectrometry. The concentration of neurotransmitters and behavioral indicators were assessed by t test and Pearson correlation analysis using SPSS 22.0. RESULTS: The Clockdelta19 mutant mice showed a significant increase in activity, albeit with no difference in the level of anxiety from the wild-type controls, which suggested that the Clockdelta19 mutant mice can be used as a model for manic attack of bipolar disorder. Altered neurotransmitter levels were detected in the frontal and hippocampal regions, including elevated histamine in the left hippocampus, reduced histamine in the right hippocampus, reduced gamma-aminobutyric acid (GABA) in bilateral hippocampus, elevated dihydroxyphenylalanine (DOPA) in the left frontal lobe and reduced DOPA in the right hippocampus, and decreased glutamine in bilateral frontal lobes. The reduced glutamine in the left frontal lobe and GABA in the right hippocampus correlated with the increased activity of Clockdelta19 mutant mice. CONCLUSION: Clockdelta19 mutant mice showed abnormal behavior with increased activity. Reduced glutamine in the left frontal lobe and GABA in the right hippocampus were correlated with increased activity.

Comparison of ethanol concentrations in the human brain determined by magnetic resonance spectroscopy and serum ethanol concentrations.

AIMS: Ethanol is a widespread substance that inherits desired effects, but also negative consequences with regard to DUI or battery. Where required, the ethanol concentration is usually determined in peripheral venous blood samples, while the brain is the target organ of the ethanol effects. The aim of this study with three participants was the determination of the ethanol concentration in functionally relevant regions of the brain and the comparison with serum ethanol concentrations. DESIGN: After the uptake of ethanol in a calculated amount, leading to a serum ethanol concentration of 0.99 g/L, the ethanol concentrations in the brain were directly analyzed by means of magnetic resonance spectroscopy on a 3 Tesla human MRI system and normalized to the water content. The measurement voxels were located in the occipital cortex, the cerebellum, the frontal cortex, and the putamen and successively examined. Intermittently blood samples were taken, and serum was analyzed for ethanol using HS-GC-FID. FINDINGS AND CONCLUSIONS: Ethanol concentrations in brain regions normalized to the water content were lower than the measured serum ethanol results and rather homogenous within the three participants and the various regions of the brain. The maximum ethanol concentration in the brain (normalized to water content) was 0.68 g/L. It was measured in the frontal cortex, in which the highest results were gained. The maximum serum concentration was 1.19 g/L. The course of the brain ethanol curve seems to be flatter than the one of the serum ethanol concentrations.

Evidence of language-related left hypofrontality in Major Depression: An EEG Beta band study.

Major depression (MDD) has been associated with an altered EEG frontal asymmetry measured in resting state; nevertheless, this association has showed a weak consistency across studies. In the present study, which starts from an evolutionistic view of psychiatric disorders, we investigated frontal asymmetry in MDD, using language as a probe to test the integrity of large inter- and intra-hemispheric networks and processes. Thirty MDD patients (22 women) and 32 matched controls (HC) were recruited for an EEG recording in resting state and during two linguistic tasks, phonological and semantic. Normalized alpha and beta EEG spectral bands were measured across all three conditions in the two groups. EEG alpha amplitude showed no hemispheric asymmetry, regardless of group, both at rest and during linguistic tasks. During resting state, analysis of EEG beta revealed a lack of hemispheric asymmetry in both groups, but during linguistic tasks, HC exhibited the typical greater left frontal beta activation, whereas MDD patients showed a lack of frontal asymmetry and a significantly lower activation of left frontal sites. In depressed patients, positive affect was negatively correlated with depression levels and positively correlated with left frontal EEG beta amplitude. Language represents the human process that requires the largest level of integration between and within the hemispheres; thus, language asymmetry was a valid probe to test the left frontal alteration encompassing highly impairing psychiatric disorders, such as schizophrenia and MDD. Indeed, these severe diseases are marked by delusions, ruminations, thought disorders, and hallucinations, all of which have a clear linguistic or metalinguistic basis.

Quantitative MRI and laser ablation-inductively coupled plasma-mass spectrometry imaging of iron in the frontal cortex of healthy controls and Alzheimer's disease patients.

Accumulation of iron within the cortex of Alzheimer's disease (AD) patients has been reported by numerous MRI studies using iron-sensitive methods. Validation of iron-sensitive MRI is important for the interpretation of in vivo findings. In this study, the relation between the spatial iron distribution and T2∗-weighted MRI in the human brain was investigated using a direct comparison of spatial maps of iron as detected by T2∗-weighted MRI, iron histochemistry and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), in postmortem brain tissue of the medial frontal gyrus of three control subjects and six AD patients. In addition, iron levels measured by LA-ICP-MS and three quantitative MRI methods, namely R2∗ (=1/T2∗), image phase and quantitative susceptibility mapping (QSM), were compared between 19 AD and 11 controls. Histochemistry results we obtained with the modified Meguro staining were highly correlated with iron levels as detected by LA-ICP-MS (r2 â€‹= â€‹0.82, P â€‹< â€‹0.0001). Significant positive correlations were also found between LA-ICP-MS and the three quantitative MRI measurements: R2∗ (r2 â€‹= â€‹0.63), image phase (r2 â€‹= â€‹0.70) and QSM (r2 â€‹= â€‹0.74 (all p â€‹< â€‹0.0001)). R2∗ and QSM showed the strongest correlation with iron content; the correlation of phase with iron clearly showed increased variation, probably due to its high orientation dependence. Despite the obvious differences in iron distribution patterns within the cortex between AD patients and controls, no overall significant differences were found in iron as measured by LA-ICP-MS, nor in R2∗, phase or susceptibility. In conclusion, our results show that histochemistry as well as quantitative MRI methods such as R2∗ mapping and QSM provide reliable measures of iron distribution in the cortex. These results support the use of MRI studies focusing on iron distribution in both the healthy and the diseased brain.

27-Plex Tandem Mass Tag Mass Spectrometry for Profiling Brain Proteome in Alzheimer's Disease.

Multiplexed isobaric labeling methods, such as tandem mass tags (TMT), remarkably improve the throughput of quantitative mass spectrometry. Here, we present a 27-plex TMT method coupled with two-dimensional liquid chromatography (LC/LC) for extensive peptide fractionation and high-resolution tandem mass spectrometry (MS/MS) for peptide quantification and then apply the method to profile the complex human brain proteome of Alzheimer's disease (AD). The 27-plex method combines multiplexed capacities of the 11-plex and the 16-plex TMT, as the peptides labeled by the two TMT sets display different mass and hydrophobicity, which can be well separated in LC-MS/MS. We first systematically optimized the protocol for the newly developed 16-plex TMT, including labeling reaction, desalting, and MS conditions, and then directly compared the 11-plex and 16-plex methods by analyzing the same human AD samples. Both methods yielded similar proteome coverage, analyzing >100 000 peptides in >10 000 human proteins. Furthermore, the 11-plex and 16-plex samples were mixed for a 27-plex assay, resulting in more than 8000 protein measurements within the same MS time. The 27-plex results are highly consistent with those of the individual 11-plex and 16-plex TMT analyses. We also used these proteomics data sets to compare the AD brain with the nondementia controls, discovering major AD-related proteins and revealing numerous novel protein alterations enriched in the pathways of amyloidosis, immunity, mitochondrial, and synaptic functions. Overall, our data strongly demonstrate that this new 27-plex strategy is highly feasible for routine large-scale proteomic analysis.

An epigenome-wide association study of posttraumatic stress disorder in US veterans implicates several new DNA methylation loci.

BACKGROUND: Previous studies using candidate gene and genome-wide approaches have identified epigenetic changes in DNA methylation (DNAm) associated with posttraumatic stress disorder (PTSD). METHODS: In this study, we performed an EWAS of PTSD in a cohort of Veterans (n = 378 lifetime PTSD cases and 135 controls) from the Translational Research Center for TBI and Stress Disorders (TRACTS) cohort assessed using the Illumina EPIC Methylation BeadChip which assesses DNAm at more than 850,000 sites throughout the genome. Our model included covariates for ancestry, cell heterogeneity, sex, age, and a smoking score based on DNAm at 39 smoking-associated CpGs. We also examined in EPIC-based DNAm data generated from pre-frontal cortex (PFC) tissue from the National PTSD Brain Bank (n = 72). RESULTS: The analysis of blood samples yielded one genome-wide significant association with PTSD at cg19534438 in the gene G0S2 (p = 1.19 × 10-7, padj = 0.048). This association was replicated in an independent PGC-PTSD-EWAS consortium meta-analysis of military cohorts (p = 0.0024). We also observed association with the smoking-related locus cg05575921 in AHRR despite inclusion of a methylation-based smoking score covariate (p = 9.16 × 10-6), which replicates a previously observed PGC-PTSD-EWAS association (Smith et al. 2019), and yields evidence consistent with a smoking-independent effect. The top 100 EWAS loci were then examined in the PFC data. One of the blood-based PTSD loci, cg04130728 in CHST11, which was in the top 10 loci in blood, but which was not genome-wide significant, was significantly associated with PTSD in brain tissue (in blood p = 1.19 × 10-5, padj = 0.60, in brain, p = 0.00032 with the same direction of effect). Gene set enrichment analysis of the top 500 EWAS loci yielded several significant overlapping GO terms involved in pathogen response, including "Response to lipopolysaccharide" (p = 6.97 × 10-6, padj = 0.042). CONCLUSIONS: The cross replication observed in independent cohorts is evidence that DNA methylation in peripheral tissue can yield consistent and replicable PTSD associations, and our results also suggest that that some PTSD associations observed in peripheral tissue may mirror associations in the brain.

Controlled ozone therapy modulates the neurodegenerative changes in the frontal cortex of the aged albino rat.

Aging is a normal process associated with neurodegenerative changes resulting in decline of cognitive and motor functions. Oxidative stress plays an important role. Controlled ozone (O3) therapy has been proved to induce oxidative preconditioning thus reversing oxidative stress. To the best of our knowledge, this research is the first attempt to investigate whether the antioxidant properties of O3 can ameliorate age-associated structural alterations of the cerebral cortex. Ozone administration (at a dose of 0.7mg/kg intraperitonially, three times a week for eight weeks) produced significant downregulation of tissue malondialdehyde (MDA) and upregulation of glutathione, superoxide dismutase (SOD) and catalase (CAT) within the frontal cortex of aged rats. Sections of the frontal cortex from adult and aged rats were stained with hematoxylin and eosin and analyzed using light microscopy. In addition, quantitative immunohistochemical assessments of the expression of inducible nitric oxide synthase (iNOS), caspase-3, glial fibrillary acidic protein (GFAP), Ki67 and acetylcholinesterase (AChE) were performed. Our results revealed the beneficial effect of O3 in improving the neurodegenerative changes of the cerebral cortex of aged rats. Moreover, this study clarified that O3 exerted its effects via reducing oxidative stress, apoptosis, gliosis as well as improving neurogenesis and cholinergic plasticity. This work added to the previously proved aging - associated neurodegenerative effects and provided a new insight into the promising role of O3 to ameliorate these effects.

Quantitative analysis of noncoding RNA from paired fresh and formalin-fixed paraffin-embedded brain tissues.

Formalin-fixed paraffin-embedded (FFPE) tissues are commonly used both clinically and in forensic pathology. Recently, noncoding RNA (ncRNA) has attracted interest among molecular medical researchers. However, it remains unclear whether newly identified ncRNAs, such as long noncoding RNA (lncRNA) and circular RNA (circRNA), remain stable for downstream molecular analysis in FFPE tissues. Here, we assessed the feasibility of using autoptic FFPE brain tissues from eight individuals to perform quantitative molecular analyses. Selected RNA targets (9 mRNAs and 15 ncRNAs) with different amplicon lengths were studied by RT-qPCR in paired fresh and FFPE specimens. For RNA quality assessment, RNA purity and yield were comparable between the two sample cohorts; however, the RNA integrity number decreased significantly during FFPE sampling. Amplification efficiency also displayed certain variability related with amplicon length and RNA species. We found molecular evidence that short amplicons of mRNA, lncRNA, and circRNA were amplified more efficiently than long amplicons. With the assistance of RefFinder, 5S, SNORD48, miR-103a, and miR-125b were selected as reference genes given their high stability. After normalization, we found that short amplicon markers (e.g., ACTB mRNA and MALAT1 lncRNA) exhibited high consistency of quantification in paired fresh/FFPE samples. In particular, circRNAs (XPO1, HIPK3, and TMEM56) presented relatively consistent and stable expression profiles in FFPE tissues compared with their corresponding linear transcripts. Additionally, we evaluated the influence of prolonged storage time on the amplification of gene transcripts and found that short amplicons still work effectively in archived FFPE biospecimens. In conclusion, our findings demonstrate the possibility of performing accurate quantitative analysis of ncRNAs using short amplicons and standardized RT-qPCR assays in autopsy-derived FFPE samples.

Kinesin light chain-1 serine-460 phosphorylation is altered in Alzheimer's disease and regulates axonal transport and processing of the amyloid precursor protein.

Damage to axonal transport is an early pathogenic event in Alzheimer's disease. The amyloid precursor protein (APP) is a key axonal transport cargo since disruption to APP transport promotes amyloidogenic processing of APP. Moreover, altered APP processing itself disrupts axonal transport. The mechanisms that regulate axonal transport of APP are therefore directly relevant to Alzheimer's disease pathogenesis. APP is transported anterogradely through axons on kinesin-1 motors and one route for this transport involves calsyntenin-1, a type-1 membrane spanning protein that acts as a direct ligand for kinesin-1 light chains (KLCs). Thus, loss of calsyntenin-1 disrupts APP axonal transport and promotes amyloidogenic processing of APP. Phosphorylation of KLC1 on serine-460 has been shown to reduce anterograde axonal transport of calsyntenin-1 by inhibiting the KLC1-calsyntenin-1 interaction. Here we demonstrate that in Alzheimer's disease frontal cortex, KLC1 levels are reduced and the relative levels of KLC1 serine-460 phosphorylation are increased; these changes occur relatively early in the disease process. We also show that a KLC1 serine-460 phosphomimetic mutant inhibits axonal transport of APP in both mammalian neurons in culture and in Drosophila neurons in vivo. Finally, we demonstrate that expression of the KLC1 serine-460 phosphomimetic mutant promotes amyloidogenic processing of APP. Together, these results suggest that increased KLC1 serine-460 phosphorylation contributes to Alzheimer's disease.

Strength of resting state functional connectivity and local GABA concentrations predict oral reading of real and pseudo-words.

Reading is a learned activity that engages multiple cognitive systems. In a cohort of typical and struggling adult readers we show evidence that successful oral reading of real words is related to gamma-amino-butyric acid (GABA) concentration in the higher-order language system, whereas reading of unfamiliar pseudo-words is not related to GABA in this system. We also demonstrate the capability of resting state functional connectivity (rsFC) combined with GABA measures to predict single real word compared to pseudo-word reading performance. Results show that the strength of rsFC between left fusiform gyrus (L-FG) and higher-order language systems predicts oral reading behavior of real words, irrespective of the local concentration of GABA. On the other hand, pseudo-words, which require grapheme-to-phoneme conversion, are not predicted by the connection between L-FG and higher-order language system. This suggests that L-FG may have a multi-functional role: lexical processing of real words and grapheme-to-phoneme processing of pseudo-words. Additionally, rsFC between L-FG, pre-motor, and putamen areas are positively related to the oral reading of both real and pseudo-words, suggesting that text may be converted into a phoneme sequence for speech initiation and production regardless of whether the stimulus is a real word or pseudo-word. In summary, from a systems neuroscience perspective, we show that: (i) strong rsFC between higher order visual, language, and pre-motor areas can predict and differentiate efficient oral reading of real and pseudo-words. (ii) GABA measures, along with rsFC, help to further differentiate the neural pathways for previously learned real words versus unfamiliar pseudo-words.

Lower myelin-water content of the frontal lobe in childhood absence epilepsy.

OBJECTIVE: The frontal lobe in childhood absence epilepsy (CAE) might be affected due to the suggested involvement of the frontal lobe during absence seizures and reports on attentional deficits. Previously, subtle white matter abnormalities have been reported in CAE. However, the impact of one of the most characteristic components of the white matter, the myelin content, remains underdetermined. Therefore, this study investigated whether the myelin content in frontal areas is adversely affected in CAE compared to controls. METHODS: Seventeen children with childhood absence epilepsy (mean age ± standard deviation [SD], 9.2 ± 2.1 years) and 15 age- and sex-matched controls (mean age ± SD, 9.8 ± 1.8 years) underwent neuropsychological assessment and a magnetic resonance imaging (MRI) examination. T2 relaxometry scans were used to distinguish myelin-water from tissue water and to determine the myelin-water fraction (MWF) in the frontal, temporal, parietal, occipital, and insular lobes. A linear regression model including age and sex as covariates was used to investigate group differences. Furthermore, the relationship of MWF with cognitive performance and epilepsy characteristics was determined. RESULTS: The frontal lobe revealed a significantly lower myelin-water content in children with CAE compared to controls over the developmental age range of 6-12 years (5.7 ± 1.0% vs 6.6 ± 1.1%, P = 0.02). This association was not found for any of the other four lobes (P > 0.10). No significant relation was found between myelin-water content and cognitive performance or epilepsy characteristics. SIGNIFICANCE: The lower frontal myelin-water content of children with CAE in comparison with healthy controls probably reflects an altered neurodevelopmental aspect in CAE, of which the underlying mechanisms still need to be unraveled.

Benzophenone-2 Concentration and Its Effect on Oxidative Stress and Apoptosis Markers in Rat Brain.

Benzophenones, frequently used as UV chemical filters, are absorbed through the skin and can exert systemic adverse effects. So far, most of the data are related to their action on sex hormone receptors whereas potential neurotoxic effect is expected mainly on the basis of in vitro studies. The aim of the present study was to determine concentrations of BP-2, oxidative stress and apoptosis markers in the rat brain after topical administration of this compound. Male Wistar rats were treated dermally with BP-2 (100 mg/kg, 4 weeks), and next, blood and tissue BP-2 concentrations and oxidative stress and apoptotic markers in the frontal cortex and hippocampus were determined. After dermal BP-2 administration, blood level of this compound was about 300 ng/ml while in the liver and adipose tissue 1354 and 823 ng/g wt tissue, respectively. In the studied brain structures, the levels of the test compound were from 5 to 19 ng/g tissue. In the hippocampus, where BP-2 level was about 3.5-fold lower than in the frontal cortex, no significant changes in either oxidative stress and apoptosis markers were observed. There was also no change in apoptosis markers in the frontal cortex but unexpectedly the oxidative stress markers were reduced. The research showed that BP-2 passes through the blood-brain barrier but its concentration in the brain structures are much lower than in the blood. This compound did not exacerbate oxidative stress and apoptosis markers in the hippocampus and frontal cortex, and even lowered oxidative stress in the frontal cortex.

Neuropeptidase activity in the frontal cortex of Wistar-Kyoto and spontaneously hypertensive rats treated with vasoactive drugs: a bilateral study.

BACKGROUND AND OBJECTIVE: Hypertension can lead to mood disorders that may worsen or ameliorate depending on the type of antihypertensive prescribed. Depression is associated with modifications in basal brain asymmetry particularly that of the frontal cortex, which is involved in blood pressure control. Furthermore, different vasoactive drugs may change the brain's asymmetry in a manner that contributes to cognition status. We studied the bilateral activity of several neuropeptidases in frontal cortex as a reflect of the functional status of certain neuropeptides involved in mood. METHODS: Using arylamide derivatives as substrates, we fluorometrically analysed the activity of these enzymes in the left and right frontal cortex of control untreated Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHRs) and compared their activities with WKY or SHR treated with the antihypertensive drugs captopril (CAP) and propranolol (PRO) or with the hypertensive N (G)-nitro-L-arginine methyl ester. SBP was also measured in all WKY and SHR groups. RESULTS: Untreated WKY, WKY treated with CAP or PRO and SHR treated with CAP exhibited normotensive values of SBP. However, WKY treated with N (G)-nitro-L-arginine methyl ester as well as untreated SHR and SHR treated with PRO and N(G)-nitro-L-arginine methyl ester demonstrated hypertensive values of SBP. Changes in the bilateral distribution of neuropeptidases were depending on the strain, the enzyme analysed and the drug used. Normotensive WKY groups (WKY, CAP, PRO) revealed intrahemispheric correlations mainly in the left hemisphere. In contrast, WKY treated with N(G)-nitro-L-arginine methyl ester and SHR groups demonstrated intrahemispheric correlations mainly in the right hemisphere. Interhemispheric correlations were mostly observed in WKY as well as in SHR groups with antihypertensive treatments (CAP, PRO). CONCLUSION: Our results suggest specific brain bilateral patterns of neuropeptidase activities in WKY that change in SHR. This observation may be related to the cognitive disorders that have been described in these animals and that change under antihypertensive or hypertensive drug's treatments.

CLIPick: a sensitive peak caller for expression-based deconvolution of HITS-CLIP signals.

High-throughput sequencing of RNAs isolated by crosslinking immunoprecipitation (HITS-CLIP, also called CLIP-Seq) has been used to map global RNA-protein interactions. However, a critical caveat of HITS-CLIP results is that they contain non-linear background noise-different extent of non-specific interactions caused by individual transcript abundance-that has been inconsiderately normalized, resulting in sacrifice of sensitivity. To properly deconvolute RNA-protein interactions, we have implemented CLIPick, a flexible peak calling pipeline for analyzing HITS-CLIP data, which statistically determines the signal-to-noise ratio for each transcript based on the expression-dependent background simulation. Comprising of streamlined Python modules with an easy-to-use standalone graphical user interface, CLIPick robustly identifies significant peaks and quantitatively defines footprint regions within which RNA-protein interactions were occurred. CLIPick outperforms other peak callers in accuracy and sensitivity, selecting the largest number of peaks particularly in lowly expressed transcripts where such marginal signals are hard to discriminate. Specifically, the application of CLIPick to Argonaute (Ago) HITS-CLIP data were sensitive enough to uncover extended features of microRNA target sites, and these sites were experimentally validated. CLIPick enables to resolve critical interactions in a wide spectrum of transcript levels and extends the scope of HITS-CLIP analysis. CLIPick is available at: http://clip.korea.ac.kr/clipick/.