Behavioural and electrophysiological modulations induced by transcranial direct current stimulation in healthy elderly and Alzheimer’s disease patients: A pilot study

Available online 26 August 2019Objective To investigate whether anodal and cathodal transcranial direct current stimulation (tDCS) can modify cognitive performance and neural activity in healthy elderly and Alzheimer’s disease (AD) patients. Methods Fourteen healthy elderly and twelve AD patients performed a working memory task during an electroencephalogram recording before and after receiving anodal, cathodal, and sham tDCS over the left dorsolateral prefrontal cortex. Behavioural performance, event-related potentials (P200, P300) and evoked cortical oscillations were studied as correlates of working memory. Results Anodal tDCS increased P200 and P300 amplitudes in healthy elderly. Cathodal tDCS increased P200 amplitude and frontal theta activity between 150 and 300 ms in AD patients. Improved working memory after anodal tDCS correlated with increased P300 in healthy elderly. In AD patients, slight tendencies between enhanced working memory and increased P200 after cathodal tDCS were observed. Conclusions Functional neural modulations were promoted by anodal tDCS in healthy elderly and by cathodal tDCS in AD patients. Significance Interaction between tDCS polarity and the neural state (e.g., hyper-excitability exhibited by AD patients) suggests that appropriate tDCS parameters (in terms of tDCS polarity) to induce behavioural improvements should be chosen based on the participant’s characteristics. Future studies using higher sample sizes should confirm and extend the present findings.This study was funded by the Italian Ministry of Health GR-2011-02349998 to MCP and the European Commission Marie-Skłodowska Curie Actions, Individual Fellowships; 655423-NIBSAD to JC

Hydrogen peroxide is a neuronal alarmin that triggers specific RNAs, local translation of Annexin A2, and cytoskeletal remodeling in Schwann cells

Schwann cells are key players in neuro-regeneration: They sense "alarm" signals released by degenerating nerve terminals and differentiate toward a proregenerative phenotype, with phagocytosis of nerve debris and nerve guidance. At the murine neuromuscular junction, hydrogen peroxide (H2O2) is a key signal of Schwann cells' activation in response to a variety of nerve injuries. Here we report that Schwann cells exposed to low doses of H2O2 rewire the expression of several RNAs at both transcriptional and translational levels. Among the genes positively regulated at both levels, we identified an enriched cluster involved in cytoskeleton remodeling and cell migration, with the Annexin (Anxa) proteins being the most represented family. We show that both Annexin A2 (Anxa2) transcript and protein accumulate at the tips of long pseudopods that Schwann cells extend upon H2O2 exposure. Interestingly, Schwann cells reply to this signal and to nerve injury by locally translating Anxa2 in pseudopods, and undergo an extensive cytoskeleton remodeling. Our results show that, similarly to neurons, Schwann cells take advantage of local protein synthesis to change shape and move toward damaged axonal terminals to facilitate axonal regeneration

Customized Application of tDCS for Clinical Rehabilitation in Alzheimer's Disease

Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by cognitive-behavior deficits, which strongly impact daily-life activities (Weintraub et al., 2012). Currently, the limited efficacy of pharmacological treatments has encouraged researchers to develop nonpharmacological interventions, such as cognitive training and non-invasive brain stimulation (NIBS) treatments, designed to prevent or delay cognitive impairment (Cass, 2017; Cespón et al., 2018)

The Italian Sensorimotor Norms: Perception and action strength measures for 959 words

Neuroscience research has provided evidence that semantic information is stored in a distributed brain network involved in sensorimotor and linguistic processing. More specifically, according to the embodied cognition accounts, the representation of concepts is deemed as grounded in our bodily states. For these reasons, normative measures of words should provide relevant information about the extent to which each word embeds perceptual and action properties. In the present study, we collected ratings for 959 Italian nouns and verbs from 398 volunteers, recruited via an online platform. The words were mostly taken from the Italian adaptation of the Affective Norms for English Words (ANEW). A pool of 145 verbs was added to the original set. All the words were rated on 11 sensorimotor dimensions: six perceptual modalities (vision, audition, taste, smell, touch, and interoception) and five effectors (hand-arm, foot-leg, torso, mouth, head). The new verbs were also rated on the ANEW dimensions. Results showed good reliability and consistency with previous studies. Relations between perceptual and motor dimensions are described and interpreted, along with relations between the sensorimotor and the affective dimensions. The currently developed dataset represents an important novelty, as it includes different word classes, i.e., both nouns and verbs, and integrates ratings of both sensorimotor and affective dimensions, along with other psycholinguistic parameters; all features only partially accomplished in previous studies

Emissões pela queima de biomassa no Estado de Santa Catarina - ano base 2017-2018

O estado de Santa Catarina (SC) é a região do Brasil com o maior número de indústrias per capita (29 indústrias para cada 10.000 habitantes) (IBGE, 2013). Além disso, segundo o Departamento Nacional de Trânsito, SC possui o maior número de carros por pessoa (DENATRAN, 2017). Vale salientar também que o estado alcançou a 9ª posição no ranking nacional de produção agrícola, apesar de concentrar apenas 1% do território nacional (IBGE, 2017). Mesmo diante dos aspectos ambientalmente negativos resultantes do intenso crescimento do setor industrial, agropecuário e frota veicular em SC, poucas iniciativas foram tomadas para monitorar as emissões e controlar os impactos na atmosfera. Até o presente momento, não existe monitoramento público da concentração de poluentes atmosféricos, exceto os realizados para cunho científico (IEMA, 2014). O projeto tem o objetivo de estimar o impacto das emissões veiculares, industriais, naturais e de queimadas na qualidade do ar em SC. Esta pesquisa dará subsídios para a elaboração de um sistema de Gestão da Qualidade do Ar em nível estadual. Entre os produtos listados no plano de trabalho, está a elaboração de inventários das emissões pela queima de biomassa, sendo este o tema do presente relatório. Este documento apresenta o relatório de emissões pela queima de biomassa no estado de Santa Catarina referente aos anos de 2017 e 2018. É importante frisar que as queimadas são as fontes mais importantes de emissões de poluentes atmosféricos em escala nacional. Logo, o estudo destas emissões é de suma importância. O LCQAr se comprometeu em auxiliar na prevenção de impactos na saúde e meio ambiente relacionados à má qualidade do ar em SC. O desafio é complexo e exigirá esforços por parte da comunidade acadêmica, bem como a importante participação de iniciativas públicas e privadas.FAPES

Role of heme oxygenase in modulating endothelial function in mesenteric small resistance arteries of spontaneously hypertensive rats.

It has been proposed that endothelial dysfunction is due to the excessive degradation of nitric oxide (NO) by oxidative stress. The enzyme heme-oxygenase (HO) seems to exert a protective effect on oxidative stress in the vasculature, both in animal models and in humans. The objective of this study is to evaluate the effects of inhibition or activation of HO on endothelial function in mesenteric small resistance arteries of spontaneously hypertensive rats (SHR). Six SHR were treated with cobalt protoporphyrin IX 50 mg/Kg (CoPP), an activator of HO; six SHR with stannous mesoporphyrin 30 mg/Kg (SnMP), an inhibitor of HO, and six SHR with saline. As controls, six Wistar-Kyoto rats (WKY) were treated with CoPP, six WKY with SnMP, and six WKY with saline. Drugs were injected in the peritoneum once a week for 2 weeks. Systolic blood pressure (SBP) was measured (tail cuff method) before and after treatment. Mesenteric small resistance arteries were mounted on a micromyograph. Endothelial function was evaluated as a cumulative concentration-response curve to acetylcholine (ACH), before and after pre-incubation with N(G)-methyl-L-arginine (L-NMMA, inhibitor of NO synthase), and to bradykinin (BK). In SHR treatment with CoPP, improved ACH-and BK-induced vasodilatation (ANOVA p < 0.001) and this improvement was abolished by L-NMMA (ANOVA p < 0.001). SnMP was devoid of effects on endothelial function. In WKY, both activation and inhibition of HO did not substantially affect endothelium-mediated vasodilatation. The stimulation of HO seems to induce an improvement of endothelial dysfunction in SHR by possibly reducing oxidative stress and increasing NO availability

Differences and similarities in early atherosclerosis between patients with non-alcoholic steatohepatitis and chronic hepatitis B and C.

Background/Aims:To compare carotid intima-media thickness (IMT) \u2013 an index of early atherosclerosis \u2013 among patients with non-alcoholic steatohepatitis (NASH), patients with chronic hepatitis B (HBV) or C (HCV) and control subjects. Methods:We studied 60 consecutive patients with biopsy-proven NASH, 60 patients with HCV, 35 patients with HBV, and 60 healthy controls who were comparable for age and sex. Common carotid IMT was measured with ultrasonography in all participants by a single operator blinded to subjects\u2019 characteristics. Results: Carotid IMT measurements were markedly different among the groups; the lowest values were in controls, intermediate in patients with HBV or HCV, and highest in those with NASH (0.84 \ub1 0.1 vs. 0.97 \ub1 0.1 vs. 1.09 \ub1 0.2 vs. 1.23 \ub1 0.2 mm, respectively; p < 0.001). The marked differences in carotid IMT that were observed among the groups were little affected by adjustment for age, sex, body mass index, smoking, LDL cholesterol, insulin resistance (by homeostasis model assessment) and components of the Adult Treatment Panel III-defined metabolic syndrome. Concordantly, in logistic regression analysis, NASH, HBV and HCV predicted carotid IMT independent of potential confounders. Conclusions: These data suggest that NASH, HCV and HBV are strongly associated with early atherosclerosis independent of classical risk factors, insulin resistance and metabolic syndrome components

PPARδ binding to heme oxygenase 1 promoter prevents angiotensin II-induced adipocyte dysfunction in Goldblatt hypertensive rats

Abstract: OBJECTIVE: Renin–angiotensin system (RAS) regulates adipogenic response with adipocyte hypertrophy by increasing oxidative stress. Recent studies have shown the role of peroxisome proliferator-activated receptor-d (PPARδ) agonist in attenuation of angiotensin II-induced oxidative stress. The aim of this study was to explore a potential mechanistic link between PPARδ and the cytoprotective enzyme heme oxygenase-1 (HO-1) and to elucidate the contribution of HO-1 to the adipocyte regulatory effects of PPARδ agonism in an animal model of enhanced RAS, the Goldblatt 2 kidney 1 clip (2K1C) model. METHOD: We first established a direct stimulatory effect of the PPARδ agonist (GW 501516) on the HO-1 gene by demonstrating increased luciferase activity in COS-7 cells transfected with a luciferase-HO-1 promoter construct. Sprague-Dawley rats were divided into four groups: sham-operated animals, 2K1C rats and 2K1C rats treated with GW 501516, in the absence or presence of the HO activity inhibitor, stannous mesoporphyrin (SnMP). RESULTS: 2K1C animals had increased visceral adiposity, adipocyte hypertrophy, increased inflammatory cytokines, increased circulatory and adipose tisssue levels of renin and Ang II along with increased adipose tissue gp91 phox expression (Po0.05) when compared with sham-operated animals. Treatment with GW 501516 increased adipose tissue HO-1 and adiponectin levels (Po0.01) along with enhancement of Wnt10b and b-catenin expression. HO-1 induction was accompanied by the decreased expression of Wnt5b, mesoderm specific transcript (mest) and C/EBPa levels and an increased number of small adipocytes (Po0.05). These effects of GW501516 were reversed in 2K1C animals exposed to SnMP (Po0.05). CONCLUSION: Taken together, our study demonstrates, for the first time, that increased levels of Ang II contribute towards adipose tissue dysregulation, which is abated by PPARδ-mediated upregulation of the heme-HO system. These findings highlight the pivotal role and symbiotic relationship of HO-1, adiponectin and PPARδ in the regulation of metabolic homeostasis in adipose tissues