Methylmercury localization in Danio rerio retina after trophic and subchronic exposure: A basis for neurotoxicology

Methylmercury is a known neurotoxic organometal which affects visual functions and few studies concerns to wild fish are available. The autometallography mercury distribution in the retina of Danio rerio was mapped using light and electron microscopy. Abundant mercury deposits were found in the photoreceptor layer (outer and inner segments of the photoreceptors) and in the inner and outer nuclear layers. Occasionally, the presence of mercury deposits in plexiform layers was observed and very rarely in the ganglion cell layer. Also the occurrence of mercury deposits in cells from the disc region was observed, but not in the nerve fiber layer. An interesting difference was found between mercury accumulation in the central and peripheral regions of the retina. These results demonstrate that mercury after trophic exposure to Danio rerio is able to cross the blood-retina barrier and accumulate in the cells of the retina even under subchronic exposure. (C) 2010 Elsevier Inc. All rights reserved.

Expression Profile of Rat Hippocampal Neurons Treated with the Neuroprotective Compound 2,4-Dinitrophenol: Up-Regulation of cAMP Signaling Genes

2,4-Dinitrophenol (DNP) is classically known as a mitochondrial uncoupler and, at high concentrations, is toxic to a variety of cells. However, it has recently been shown that, at subtoxic concentrations, DNP protects neurons against a variety of insults and promotes neuronal differentiation and neuritogenesis. The molecular and cellular mechanisms underlying the beneficial neuroactive properties of DNP are still largely unknown. We have now used DNA microarray analysis to investigate changes in gene expression in rat hippocampal neurons in culture treated with low micromolar concentrations of DNP. Under conditions that did not affect neuronal viability, high-energy phosphate levels or mitochondrial oxygen consumption, DNP induced up-regulation of 275 genes and down-regulation of 231 genes. Significantly, several up-regulated genes were linked to intracellular cAMP signaling, known to be involved in neurite outgrowth, synaptic plasticity, and neuronal survival. Differential expression of specific genes was validated by quantitative RT-PCR using independent samples. Results shed light on molecular mechanisms underlying neuroprotection by DNP and point to possible targets for development of novel therapeutics for neurodegenerative disorders.

Oncostatin M is a novel glucocorticoid-dependent neuroinflammatory factor that enhances oligodendrocyte precursor cell activity in demyelinated sites

The innate immune reaction to tissue injury is a natural process, which can have detrimental effects in the absence of negative feedbacks by glucocorticoids (GCs). Although acute lipopolysaccharide (LPS) challenge is relatively harmless to the brain parenchyma of adult animals, the endotoxin is highly neurotoxic in animals that are treated with the GC receptor antagonist RU486. This study investigated the role of cytokines of the gp130-related family in these effects, because they are essential components of the inflammatory process that provide survival signals to neurons. Intracerebral LPS injection stimulated expression of several members of this family of cytokines, but oncostatin M (Osm) was the unique ligand to be completely inhibited by the RU486 treatment. OSM receptor (Osmr) is expressed mainly in astrocytes and endothelial cells following LPS administration and GCs are directly responsible for its transcriptional activation in the presence of the endotoxin. In a mouse model of demyelination, exogenous OSM significantly modulated the expression of genes involved in the mobilization of oligodendrocyte precursor cells (OPCs), differentiation of oligodendrocyte, and production of myelin. In conclusion, the activation of OSM signaling is a mechanism activated by TLR4 in the presence of negative feedback by GCs on the innate immune system of the brain. OSM absence is associated with detrimental effects of LPS, whereas exogenous OSM favors repair response to demyelinated regions. (C) 2010 Elsevier Inc. All rights reserved.

Prion Protein and Its Ligand Stress Inducible Protein 1 Regulate Astrocyte Development

Prion protein (PrP(C)) interaction with stress inducible protein 1 (STI1) mediates neuronal survival and differentiation. However, the function of PrP(C) in astrocytes has not been approached. In this study, we show that STI1 prevents cell death in wild-type astrocytes in a protein kinase A-dependent manner, whereas PrP(C)-null astrocytes were not affected by STI1 treatment. At embryonic day 17, cultured astrocytes and brain extracts derived from PrP(C)-null mice showed a reduced expression of glial fibrillary acidic protein (GFAP) and increased vimentin and nestin expression when compared with wild-type, suggesting a slower rate of astrocyte maturation in PrP(C)-null animals. Furthermore, PrP(C)-null astrocytes treated with STI1 did not differentiate from a flat to a process-bearing morphology, as did wild-type astrocytes. Remarkably, STI1 inhibited proliferation of both wild-type and PrP(C)-null astrocytes in a protein kinase C-dependent manner. Taken together, our data show that PrP(C) and STI1 are essential to astrocyte development and act through distinct signaling pathways.(C) 2009 Wiley-Liss, Inc.

Directed Differentiation of Neural Progenitors into Neurons Is Accompanied by Altered Expression of P2X Purinergic Receptors

Neural differentiation has been extensively studied in vitro in a model termed neurospheres, which consists of aggregates of neural progenitor cells. Previous studies suggest that they have a great potential for the treatment of neurological disorders. One of the major challenges for scientists is to control cell fate and develop ideal culture conditions for neurosphere expansion in vitro, without altering their features. Similar to human neural progenitors, rat neurospheres cultured in the absence of epidermal and fibroblast growth factors for a short period increased the levels of beta-3 tubulin and decreased the expression of glial fibrillary acidic protein and nestin, compared to neurospheres cultured in the presence of these factors. In this work, we show that rat neurospheres cultured in suspension under mitogen-free condition presented significant higher expression of P2X2 and P2X6 receptor subunits, when compared to cells cultured in the presence of growth factors, suggesting a direct relationship between P2X2/6 receptor expression and induction of neuronal differentiation in mitogen-free cultured rat neurospheres.

Processos cognitivos que operam na configuração de narrativas: uma pesquisa exploratória dos fenômenos que subjazem à compreensão de textos

This paper investigates the cognitive processes that operate in understanding narratives in this case, the novel Macunaíma, by Mário de Andrade. Our work belongs to the field of Embodied-based Cognitive Linguistics and, due to its interdisciplinary nature, it dialogues with theoretical and methodological frameworks of Psycholinguistics, Cognitive Psychology and Neurosciences. Therefore, we adopt an exploratory research design, recall and cloze tests, adapted, with postgraduation students, all native speakers of Brazilian Portuguese. The choice of Macunaíma as the novel and initial motivation for this proposal is due to the fact it is a fantastic narrative, which consists of events, circumstances and characters that are clearly distant types from what is experienced in everyday life. Thus, the novel provides adequate data to investigate the configuration of meaning, within an understanding-based model. We, therefore, seek, to answer questions that are still, generally, scarcely explored in the field of Cognitive Linguistics, such as to what extent is the activation of mental models (schemas and frames) related to the process of understanding narratives? How are we able to build sense even when words or phrases are not part of our linguistic repertoire? Why do we get emotionally involved when reading a text, even though it is fiction? To answer them, we assume the theoretical stance that meaning is not in the text, it is constructed through language, conceived as a result of the integration between the biological (which results in creating abstract imagery schemes) and the sociocultural (resulting in creating frames) apparatus. In this sense, perception, cognitive processing, reception and transmission of the information described are directly related to how language comprehension occurs. We believe that the results found in our study may contribute to the cognitive studies of language and to the development of language learning and teaching methodologies

Dimensional analysis of burden in family caregivers of patients with obsessive-compulsive disorder

Aims: Obsessivecompulsive disorder (OCD) also generates emotional burden in the patient's family members, but no study has evaluated the specific dimensions of burden. The objectives were to evaluate the dimensions of the Zarit Burden Interview (ZBI) and possible correlates. Methods: This was a cross-sectional study involving 47 patients and 47 caregivers, using a sociodemographic questionnaire; the ZBI; the Self Reporting Questionnaire; the Family Accommodation Scale; and the YaleBrown ObsessiveCompulsive Scale. The ZBI factor analysis was conducted using Varimax Rotation. Results: Six factors were identified, explaining 74.2% of the total variance: factor 1, interference in the caregiver's personal life (36.6% of the variance); factor 2, perception of patient's dependence (10.8%); factor 3, feelings of irritation or intolerance (9.2%); factor 4, guilt (7.2%); factor 5, insecurity (5.6%); and factor 6, embarrassment (4.8%). The six ZBI factors were associated with greater OCD severity and with greater accommodation to the patient's symptoms, and factors 1, 2, 5 and 6 with caregiver's psychological morbidity. Caregiver's sex (female) was associated with factors 5 and 6, relationship with the patient (being a parent or son/daughter) with factor 5, higher educational level with factor 6, living with the patient with factor 3, worse self-evaluation of health with factors 1, 5 and 6, and occupational status (not working) with factors 1, 2, 5 and 6. Conclusion: The dimensions of burden identified indicate the most affected aspects of a caregiver's life and could guide the planning of more specific interventions. Thus, the caregiver could participate more effectively in the OCD patient's treatment, with a lower impact on his/her life.

Locomoção, distúrbios neuropsiquiátricos e alterações do sono de pacientes com demência e seus cuidadores

INTRODUÇÃO: Os distúrbios neurodegenerativos representam condições clínicas graves, por provocar declínio neuropsíquico. OBJETIVO: Analisar a prevalência dos distúrbios neuropsiquiátricos em pacientes com demência, em relação à sua locomoção (independentes vs. dependentes), e no que se refere ao desgaste emocional e à qualidade do sono dos cuidadores. MATERIAIS E MÉTODOS: Participaram do estudo 34 sujeitos, assim divididos: dez pacientes independentes para locomoção e sete dependentes (cadeirantes); dez cuidadores dos pacientes independentes e sete cuidadores de pacientes dependentes. Os sujeitos foram avaliados no Ambulatório de Neuropsiquiatria da Universidade Estadual de Campinas. Para avaliar as funções cognitivas, utilizou-se o CAMCOOG; para quantificar frequência, intensidade e desgaste do cuidador, aplicou-se o Inventário Neuropsiquiátrico; e para mensurar as alterações do sono dos cuidadores, foi utilizado o Miniquestionário do Sono. A análise estatística foi realizada por meio dos testes U - Mann Whitney e índice de correlação de Spearman, ambos com 5% de significância. RESULTADOS: Com relação à prevalência dos distúrbios neuropsiquiátricos entre os pacientes, observou-se diferença estatisticamente significativa entre os grupos, especificamente no que se refere à irritabilidade (p < 0,05) e ao escore total dos distúrbios neuropsiquiátricos (p < 0,01). Também foram encontradas diferenças entre os grupos de cuidadores, com relação às alterações do sono (p < 0,05). CONCLUSÃO: Idosos independentes para locomoção apresentam menor prevalência dos distúrbios neuropsiquiátricos, quando comparados a idosos dependentes de cadeira de rodas. A locomoção parece não influenciar no desgaste físico e emocional do cuidador, mas constitui uma variável relevante na qualidade do sono dos cuidadores de idosos com diagnóstico de demência vascular e mista.

What affective neuroscience means for science of consciousness

The field of affective neuroscience has emerged from the efforts of Jaak Panksepp in the 1990s and reinforced by the work of, among others, Joseph LeDoux in the 2000s. It is based on the ideas that affective processes are supported by brain structures that appeared earlier in the phylogenetic scale (as the periaqueductal gray area), they run in parallel with cognitive processes, and can influence behaviour independently of cognitive judgements. This kind of approach contrasts with the hegemonic concept of conscious processing in cognitive neurosciences, which is based on the identification of brain circuits responsible for the processing of (cognitive) representations. Within cognitive neurosciences, the frontal lobes are assigned the role of coordinators in maintaining affective states and their emotional expressions under cognitive control. An intermediary view is the Damasio-Bechara Somatic Marker model, which puts cognition under partial somatic-affective control. We present here our efforts to make a synthesis of these views, by proposing the existence of two interacting brain circuits; the first one in charge of cognitive processes and the second mediating feelings about cognitive contents. The coupling of the two circuits promotes an endogenous feedback that supports conscious processes. Within this framework, we present the defence that detailed study of both affective and cognitive processes, their interactions, as well of their respective brain networks, is necessary for a science of consciousness.© MSM 2013.

Naturalidade: o nível profundo da comunicaçao

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Psicossomática na saúde coletiva: um enfoque biopsicossocial

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Single-pass measurement of the optical quality of the opossum eye

This paper reports the results that are part of a series of experiments designed to evaluate aspects of the spatial resolution of the visual system of the opossum, Didelphis marsupialis aurita. This nocturnal marsupial presents a well-developed eye, displaying features that reflect specialization for operation at low levels of luminosity. The species was shown to be slightly myopic, a feature that may prove to be valuable because of the increased depth of field. Opossum visual acuity has been previously evaluated by means of determining the Contrast Sensitivity Function (CSF). The results indicate rather poor visual acuity compared with other nocturnal animals. In this paper, we describe the results obtained for the optical quality of the opossum's eye using a single-pass method. The results suggest that the opossum's optical system is capable of forming images that can be resolved when separated by an angular distance on the order of 6 minutes of arc.

Memória organizacional, memória corporativa e memória institucional: discussões conceituais e terminológicas

The proposal of present paper is to present a conceptual and terminological discussion relative to the terms: organizational memory, corporate memory and institutional memory that is a subject still little studied and explored in the academic area. The study is theoretical focus and the research kind is bibliographical. As research sources were utilized: books, digital libraries of theses and dissertations in the scope of the country and CAPES Journals Portal. This study is in course and is part of doctorate research "Organizational memory and the knowledge bases constitution". As the partial results, observes that the question about "memory" is studied by different areas of knowledge: Psychology, Neurosciences, History and others; the concepts about organizational memory and corporate memory are studied by Administration and Information Systems areas; the concept of institutional memory is more studied by Business Communication area focusing the company history. Beyond that, observes the use of another term, social memory, utilized by Information Science and History areas.

Body and Didactics. Possible directions of international research

The paper investigates the role of the body in didactics. It looks up for points of contact between the functional sceneries of the classroom and some recent approaches, such like simplexity, neurosciences and enactivism. The two experiments presented they aim to demonstrate the importance of body awareness to improve the didactic quality. The first experience used a SenseWear Armband that provided data about the energetic expenditure of a teacher during diff erent activities in a lesson. Th e second experiment relied on a neurofeedback device integrated to a sensor, it detected body temperature with the aim of understanding the role of the body in the process of self-regulation-learning and management of attention and arousal.

Emoção e afetividade na aprendizagem: breve revisão bibliográfica

This work has as its theme the role of emotions and affectivity in learning, particularly in science learning, being developed from a literature review. We start from the idea that learning occurs through changes in the neural networks of each individual and that these changes are caused by a combination of genetic and biological factors also influenced by emotions and affectivity. We seek information on the functioning of the human brain, highlighting the neuroanatomy and neurocognition, to understand how the brain processes information, including the feelings and emotions experienced by the individual. Once we try to understand which roles are assigned to the feelings and emotions in different learning theories, emphasizing the cognitive and humanistic theories. Finally, we found some more recent contributions to the understanding of the learning process, to the field of neuroscience. We were led to conclude that there is great scope for research in applied neuroscience to education, since the work, especially in the national literature are still scarce