RESUMEN

Thiamine deficiency is associated with cerebellar dysfunction; however, the consequences of thiamine deficiency on the electrophysiological properties of cerebellar Purkinje cells are poorly understood. Here, we evaluated these parameters in brain slices containing cerebellar vermis. Adult mice were maintained for 12-13 days on a thiamine-free diet coupled with daily injections of pyrithiamine, an inhibitor of thiamine phosphorylation. Morphological analysis revealed a 20% reduction in Purkinje cell and nuclear volume in thiamine-deficient animals compared to feeding-matched controls, with no reduction in cell count. Under whole-cell current clamp, thiamine-deficient Purkinje cells required significantly less current injection to fire an action potential. This reduction in rheobase was not due to a change in voltage threshold. Rather, thiamine-deficient neurons presented significantly higher input resistance specifically in the voltage range just below threshold, which increases their sensitivity to current at these critical membrane potentials. In addition, thiamine deficiency caused a significant decrease in the amplitude of the action potential afterhyperpolarization, broadened the action potential, and decreased the current threshold for depolarization block. When thiamine-deficient animals were allowed to recover for 1 week on a normal diet, rheobase, threshold, action potential half-width, and depolarization block threshold were no longer different from controls. We conclude that thiamine deficiency causes significant but reversible changes to the electrophysiology properties of Purkinje cells prior to pathological morphological alterations or cell loss. Thus, the data obtained in the present study indicate that increased excitability of Purkinje cells may represent a leading indicator of cerebellar dysfunction caused by lack of thiamine.

Asunto(s)

Células de Purkinje/patología , Deficiencia de Tiamina/patología , Deficiencia de Tiamina/fisiopatología , Potenciales de Acción/fisiología , Animales , Masculino , Ratones , Ratones Endogámicos C57BL , Técnicas de Cultivo de Órganos , Técnicas de Placa-Clamp

RESUMEN

Abstract Introduction: Obesity, characterized by the accumulation of excess body fat, can alter respiratory mechanics and compromise functional capacity. Given its increasing prevalence and the significant morbidity associated with the condition, it is important to investigate techniques that enable rapid, easy measurement of lung function and the possible correlation between obesity and functional capacity. Objective: To assess lung function and functional capacity in obese adults and determine whether there is a correlation between reduced peak expiratory flow and impaired functional capacity. Methods: 30 participants, distributed into two groups: obese (36 ± 13 years) and normal weight (31 ± 9 years) were evaluated based on anthropometric measurements, the six-minute walk test (6MWT) and peak expiratory flow (PEF). Results: The obese individuals showed reduced PEF (382 ± 99 vs. 497 ± 104 L/min, p < 0.01), walked shorter distances in the 6MWT (453 ± 37 vs. 617 ± 50 m, p < 0.01), had higher blood pressure and perceived exertion (p < 0.05) when compared to normal weight participants. Additionally, there was a positive significant association between expiratory flow and distance walked in the 6MWT (r = 0.635 and p < 0.001). Conclusion: Obese individuals exhibited lower PEF and walked shorter distances in the 6MWT, indicating a positive correlation between these two variables. In light of this outcome, the assessment methods used could contribute to improving analysis of respiratory and functional status in this population and aid in exercise prescription.

---

Resumo Introdução: A obesidade, caracterizada por acúmulo excessivo de tecido adiposo no organismo, pode alterar a mecânica ventilatória, trazendo prejuízos funcionais. Considerando a prevalência crescente da obesidade, bem como a grande morbidade associada a esta condição, torna-se relevante investigar técnicas de mensuração rápidas e fáceis da função ventilatória e a possível correlação com a capacidade funcional. Objetivo: Avaliar a função ventilatória e a capacidade funcional em adultos obesos e determinar se pico de fluxo expiratório reduzido está correlacionado com prejuízo da capacidade funcional. Métodos: 30 participantes, distribuídos em dois grupos: obeso (36 ± 13 anos) e eutrófico (31 ± 9 anos) foram avaliados por meio de medidas antropométricas, do teste de caminhada de seis minutos (TC6´) e da avaliação do pico de fluxo expiratório (PFE). Resultados: Os indivíduos obesos apresentaram reduzido PFE (382 ± 99 vs. 497 ± 104 L/min, p < 0,01) e percorreram menor distância no TC6´ (453 ± 37 vs. 617 ± 50 m, p < 0,01) com maior pressão arterial e percepção de esforço (p < 0,05) quando comparados aos eutróficos. Além disso, foi encontrada correlação positiva e significativa entre fluxo expiratório e distância percorrida (r = 0,635 e p < 0,001). Conclusão: Os indivíduos obesos tiveram menor PFE e menor distância percorrida no TC6´, constatada correlação positiva entre essas duas variáveis. Diante de tal desfecho, a inclusão dos métodos avaliativos utilizados podem contribuir para melhor análise da condição respiratória e funcional dessa população e auxiliar na prescrição de exercícios.

Asunto(s)

Humanos , Ápice del Flujo Espiratorio , Prueba de Paso , Obesidad , Capacidad Residual Funcional , Morbilidad

RESUMEN

The evaluation of thiamine and its derivative phosphate esters levels in pregnant women in rural communities can contribute not only for understanding the specific characteristics of this population regarding nutritional aspects, but also for clarifying the relations of psychiatric manifestations and a vitamin deficit. In the present work we assessed sociodemographic variables, psychiatric parameters and thiamine and its derivative in the whole blood of women in a rural, low-income community in Brazil. A case-control study was done. 94 women were divided in groups using the trimesters of pregnancy as a criterion: each trimester, 1st, 2nd and 3rd had 17, 37 and 38 women, respectively. A control group of non-pregnant women (n-39) was also included. Symptoms of anxiety and depression were assessed using the HAMA Scale and Beck Inventory, respectively. The thiamine and its phosphorylated derivatives concentrations were determined in whole blood samples using the HPLC method. The results suggest that physiological mechanisms linked to the metabolic pathways of thiamine may play a role in some neurobiological substrate involved in the regulation of emotional state. Thus, social vulnerability is identified as an important factor to be considered in the evaluation of the mental health of pregnant women living in rural communities.

Asunto(s)

Trastornos Mentales/epidemiología , Complicaciones del Embarazo/epidemiología , Mujeres Embarazadas , Deficiencia de Tiamina/epidemiología , Poblaciones Vulnerables , Adolescente , Adulto , Brasil/epidemiología , Estudios de Casos y Controles , Femenino , Humanos , Trastornos Mentales/sangre , Trastornos Mentales/psicología , Pobreza/psicología , Pobreza/tendencias , Embarazo , Complicaciones del Embarazo/sangre , Complicaciones del Embarazo/psicología , Mujeres Embarazadas/psicología , Población Rural/tendencias , Deficiencia de Tiamina/sangre , Deficiencia de Tiamina/psicología , Poblaciones Vulnerables/psicología , Adulto Joven

RESUMEN

Thiamine deficiency (TD) has been used as an experimental model in rodents to study the molecular mechanisms of neurodegeneration and its association with behavioral changes. The aims of the present study were to investigate the spatial cognitive performance of pyrithiamine-induced thiamine deficiency (PTD) in adult male rats and disclose the thalamic proteome alterations caused by a severe TD episode. After the onset of the neurological signs, such as seizure and/or loss of righting reflex, the TD treatment was interrupted. Following 15 days of recovery, all rats were submitted to the spatial cognitive tasks in the Morris Water Maze (MWM). The results show that the PTD rats exhibited deficits during the learning process, which was reverted by repeated training. However, despite the spatial cognitive recovery, some protein changes were not reversible. The proteomic analysis, using label-free quantification, revealed deregulation of 183 thalamic proteins. Using bioinformatic tools, these proteins were categorized according to Gene Ontology functional annotation and metabolic pathways. We show that a severe TD affects proteins involved in different biological processes, such as, oxidative stress, neurotransmitter synthesis and synaptic vesicle cycle. These could explain the outcome in neurotransmitter release changes caused by TD, previously observed by our group and by other authors. These findings disclose the role of key proteins and metabolic pathways probably involved in the neurodegeneration process induced by TD. These proteins represent relevant molecular targets for future studies focusing also on the molecular basis of selective vulnerability of some brain areas to TD insult.

Asunto(s)

Conducta Animal/fisiología , Aprendizaje Espacial/fisiología , Tálamo/metabolismo , Deficiencia de Tiamina/metabolismo , Tiamina/metabolismo , Animales , Peso Corporal/fisiología , Cognición/fisiología , Ingestión de Alimentos/fisiología , Masculino , Proteoma , Proteómica , Ratas , Ratas Wistar

RESUMEN

BACKGROUND: Vaccination is a widespread strategy to protect women and their children during fetal development. However, there is a lack of knowledge about potential effects of H1N1 vaccination on concentration of cytokines that are important to mother's central nervous system functions and fetal neurodevelopment. OBJECTIVE: The main purpose of the present study was to evaluate such interaction. The specific goals were to study the effects of vaccination against the H1N1 virus on plasma levels of the Brain Derived Neurotrophic Factor(BDNF), Tumor Necrosis Factor-α (TNF-α) and TNF-α Receptors 1 and 2 (sTNFR1; sTNFR2), in different periods of gestation. METHODS: Data were obtained during the period of 6 months in 2010, from a sample of 94 pregnant women who were using the health care service of Conceição do Mato Dentro, a rural area in the state of Minas Gerais, Brazil. Seventeen women were in the first trimester of pregnancy, forty were in the second trimester and 37 were in the third trimester. Each of these groups was divided into two subgroups as follows: immunized against the H1N1 virus (I) and non-immunized (NI). Plasma concentrations of BDNF, TNF-α, sTNFR1 and sTNFR2 were measured using the sandwich ELISA. RESULTS: There was no difference in cytokine or neurotrophic factor levels evaluated between groups I and NI in any trimesters. CONCLUSION: These results show that the recommendation of vaccination against the H1N1 virus for all pregnant women as a public health measure could be considered safe, regarding aspects related to the role played by neurotrophin and cytokine, such as those of CNS development and immunological functions.

Asunto(s)

Factor Neurotrófico Derivado del Encéfalo/sangre , Subtipo H1N1 del Virus de la Influenza A/inmunología , Vacunas contra la Influenza/administración & dosificación , Vacunas contra la Influenza/sangre , Factor de Necrosis Tumoral alfa/sangre , Vacunación/tendencias , Adolescente , Adulto , Biomarcadores/sangre , Brasil/epidemiología , Femenino , Humanos , Gripe Humana/epidemiología , Gripe Humana/prevención & control , Embarazo , Adulto Joven

RESUMEN

Alcoholism is a psychiatric disorder that composes one of the principal causes of health disabilities in the world population. Furthermore, the available pharmacotherapy is limited. Therefore, this research was carried out to better understand the basis of the underlying neurobiological processes of this disorder and to discover potential therapeutic targets. Real-time PCR analysis was performed in the amygdala nuclei region of the brain of mice exposed to a chronic three-bottle free-choice model (water, 5 and 10% v/v ethanol). Based on individual ethanol intake, the mice were classified into three groups: "compulsive-like" (i.e., ethanol intake not affected by quinine adulteration), "ethanol-preferring" and "ethanol non-preferring". A fourth group had access only to tap water (control group). The candidate gene ACSS2 was genotyped in human alcoholics by real-time polymerase chain reaction using the markers rs6088638 and rs7266550. Seven genes were picked out (Acss2, Acss3, Acat1, Acsl1, Acaa2, Hadh, and Hadhb) and the mRNA level of the Acss2 gene was increased only in the "compulsive-like" group (p = 0.004). The allele frequency of rs6088638 for the gene ACSS2 was higher in the Alcoholic human group (p = 0.03), although sample size was very small. The gene ACSS2 is associated with alcoholism, suggesting that biochemical pathways where it participates may have a role in the biological mechanisms susceptible to the ethanol effects.

Asunto(s)

Acetato CoA Ligasa/genética , Acetato CoA Ligasa/metabolismo , Alcoholismo/enzimología , Alcoholismo/genética , Adulto , Animales , Depresores del Sistema Nervioso Central/administración & dosificación , Conducta de Elección/fisiología , Conducta Compulsiva/enzimología , Conducta Compulsiva/genética , Modelos Animales de Enfermedad , Etanol/administración & dosificación , Femenino , Frecuencia de los Genes , Humanos , Masculino , Ratones , Polimorfismo de Nucleótido Simple , ARN Mensajero/metabolismo

RESUMEN

The purposes of the present study were to investigate the effects of perinatal thiamine deficiency, from the 11th day of gestation until the 5th day of lactation, on motor behavior and neurochemical parameters in adult rat offspring, using 3-month-old, adult, male Wistar rats. All rats were submitted to motor tests, using the rotarod and paw print tasks. After behavioral tests, their thalamus, cerebellum and spinal cord were dissected for glutamate and GABA quantifications by high performance liquid chromatography. The thiamine-restricted mothers (RM) group showed a significant reduction of time spent on the rotarod at 25 rpm and an increase in hind-base width. A significant decrease of glutamate concentration in the cerebellum and an increase of GABA concentrations in the thalamus were also observed. For the offspring from control mothers (CM) group there were significant correlations between thalamic GABA concentrations and both rotarod performance and average hind-base width. In addition, for rats from the RM group a significant correlation between stride length and cerebellar GABA concentration was found. These results show that the deficiency of thiamine during an early developmental period affects certain motor behavior parameters and GABA and glutamate levels in specific brain areas. Hence, a thiamine deficiency episode during an early developmental period can induce motor impairments and excitatory and inhibitory neurotransmitter changes that are persistent and detectable in later periods of life.

Asunto(s)

Encéfalo/metabolismo , Ácido Glutámico/metabolismo , Actividad Motora , Deficiencia de Tiamina/metabolismo , Ácido gamma-Aminobutírico/metabolismo , Animales , Corteza Cerebelosa/metabolismo , Femenino , Intercambio Materno-Fetal , Bulbo Raquídeo/metabolismo , Equilibrio Postural , Embarazo , Ratas Wistar , Prueba de Desempeño de Rotación con Aceleración Constante , Tálamo/metabolismo

RESUMEN

Chronic thiamine deficiency may be responsible for pathologic changes in the brains of alcoholics, and subclinical episodes of this vitamin deficiency may cause cumulative brain damage. In the present work, the chronic effects of ethanol and its association to a mild thiamine deficiency episode (subclinical model) on neocortical and hippocampal acetylcholinesterase activity were assessed along with their possible association to spatial cognitive dysfunction. The results indicate that in the beginning of the neurodegenerative process, before the appearance of brain lesions, chronic ethanol consumption reverses the effects of mild thiamine deficiency on both spatial cognitive performance and acetylcholinesterase activity without having significant effects on any morphometric parameter.

Asunto(s)

Acetilcolinesterasa/metabolismo , Alcoholismo/metabolismo , Aprendizaje por Laberinto , Memoria Espacial , Deficiencia de Tiamina/metabolismo , Alcoholismo/complicaciones , Alcoholismo/fisiopatología , Animales , Hipocampo/metabolismo , Hipocampo/fisiopatología , Masculino , Neocórtex/metabolismo , Neocórtex/fisiopatología , Ratas , Ratas Wistar , Deficiencia de Tiamina/complicaciones , Deficiencia de Tiamina/fisiopatología

RESUMEN

The acquisition of cognitive, sensory-motor and social emotional functions depend on a proper development of the Central Nervous System (CNS). This set of functions, known as intelligence, allows a better adaptation to the environment. In the last decades, an increase in the average of intelligence has been reported. However, such an increase cannot be observed in an equivalent way in economically and social underprivileged regions. Children from those regions are in great risk of being affected by mental retardation or impaired cognitive development. In later life they will, probably, be unable to transform and improve themselves and their communities, perpetuating the poverty of the region. Therefore, knowledge of factors involved in CNS development is a matter of health closely related to social improvement. Malnutrition throughout pregnancy and breastfeeding is clearly identifiable as a cause of damage in CNS development. Vitamin B1 (Thiamine) is a micronutrient important to the growth and maturity of the CNS. Thiamine shortcoming may affect 50% of pregnant women. Thiamine function in cerebral development is still not well known. There is a gap in the literature regarding systematical research about the blood thiamine concentration throughout the periods of gestation and breastfeeding. These studies are relevant in populations with a high level of nutritional vulnerability, because in a follow up offspring cognitive exam they could reveal if the maternal thiamine deficiency is related to child CNS impairment. This paper introduce the hypothesis that thiamine shortcoming during pregnancy and breastfeeding is directly related to cognitive impairment of child. Data about the neurophysiological role of thiamine, consequences of its shortcoming in experimental models, populations under the risk of thiamine shortcoming are presented. The hypothesis that maternal thiamine shortcoming causes damage related to child cognitive development needs to be considered. Thus, thiamine shortcoming during gestation and breastfeeding and its effects on children must be studied in many populations in order to know the magnitude of the problem and to indicate actions to overcome it.

Asunto(s)

Trastornos del Conocimiento/etiología , Pobreza , Efectos Tardíos de la Exposición Prenatal/fisiopatología , Deficiencia de Tiamina/complicaciones , Sistema Nervioso Central/metabolismo , Femenino , Humanos , Embarazo , Tiamina/metabolismo

RESUMEN

Este trabalho representa uma contribuição à lacuna existente acerca da temática da Educação em Ciência na Educação Infantil, e trata da formação de professores em um ambiente específico – a Creche Fiocruz. A coleta de dados foi realizada no período de 2007 a 2010, procurando responder às questões- foco: quais as concepções de Ciências Naturais que embasam os saberes e orientam os fazeres docentes no que tange à construção de conhecimentos no cotidiano da Creche? Nosso intuito foi problematizar a forma aprendida/apreendida da educação científica e como ela se reflete no exercício das práticas pedagógicas dos professores da Educação Infantil. Desta forma, objetivamos investigar e analisar as estratégias educacionais desenvolvidas no cotidiano da Creche bem como as concepções que as embasam. Para atingirmos os objetivos propostos, desenvolvemos uma pesquisa qualitativa de cunho etnográfico com cinco professoras das turmas do Jardim, que incluiu o acompanhamento dos projetos didáticos com a observação sistemática no campo e a aplicação de questionários e entrevistas semiestruturadas, assim como os enunciados das crianças sobre os temas abordados, expressos nos desenhos infantis. Adicionalmente, foram analisados o projeto político-pedagógico da creche, além de outros documentos ligados às diretrizes oficiais para esta primeira etapa da Educação Básica. Sobre as transformações das concepções das docentes envolvidas no processo estudado, ficou evidenciada a substituição de técnicas artesanais pela adoção de uma prática metodológica que valorizava a relação das crianças com os seres vivos e com o ambiente do entorno da creche. Por outro lado, as estratégias metodológicas passaram a ser, cada vez mais, de caráter investigativo, procurando enfatizar o papel do questionamento e das dúvidas das crianças. Os encontros pontuais, como feiras de ciências, passaram a constituir um processo contínuo de construção de conhecimentos interdisciplinares em ciências ambientais e saúde. As professoras passaram a valorizar mais as hipóteses na medida em que iam percebendo a educação científica como parte fundamental da leitura de mundo, apontando a necessidade de mudanças nos cursos de graduação e na própria grade curricular da Educação Infantil. As entrevistas revelaram que as professoras foram percebendo, através das fotografias que retratavam as atividades realizadas durante o processo, o quanto poderiam melhorar seus procedimentos didáticos no sentido de favorecer uma maior interação das crianças com a natureza. Desta forma, ficou patente como o trabalho pode também colaborar, em certa medida, para uma postura mais crítica e reflexiva das docentes. As respostas também indicaram que as professoras também perceberam a importância da parceria com acadêmicos da instituição. Este contato instigou nelas o desejo de aprenderem a aprender, possibilitando transformações em suas práticas para também estimular a curiosidade infantil. A análise da produção gráfica das crianças apontou a influência das observações e vivências para o enriquecimento de sua compreensão acerca dos diferentes assuntos, como se pode notar pelo desenvolvimento da argumentação oral calcada nos desenhos. Acreditamos que este estudo possa contribuir para ampliar a discussão sobre políticas públicas, no sentido da valorização profissional da Educação Infantil e da relevância da educação científica na formação dos cidadãos.

Asunto(s)

Crianza del Niño , Docentes , Ciencia

RESUMEN

Emotion and spatial cognitive aspects were assessed in adult and middle-aged rats using the elevated T-maze (ETM) and the Morris water maze (MWM) tasks. Both adult and middle-aged rats were able to acquire inhibitory avoidance behaviour, though the middle-aged subjects showed larger latencies along the trials, including the baseline, which was significantly longer than that showed by adult rats. Further, compared to adult rats, middle-aged rats had longer escape latency. In spite of the worse performance in the second session of the spatial cognitive task, the middle-aged rats were able to learn the task and remember the information along the whole probe trial test. Both thalamic serotonin (5-HT) concentration and amygdala serotonergic activity (5-HIAA/5-HT) are significantly correlated, respectively, to escape latency and behavioural extinction in the MWM only for middle-aged rats. A significant correlation between the 5-HIAA/5-HT ratio in the amygdala and behavioural extinction for middle-aged, but not for adult, rats was observed. This result suggests that serotonergic activity in the amygdala may regulate behavioural flexibility in aged animals. In addition, a significant negative correlation was found between hippocampal 5-HIAA/5-HT ratio and the path length at the second training session of the MWM task, although only for adult subjects. This was the only session where a significant difference between the performance of middle-aged and adult rats has occurred. Although the involvement of the hippocampus in learning and memory is well established, the present work shows, for the first time, a correlation between a serotonergic hippocampal parameter and performance of a spatial task, which is lost with ageing.

Asunto(s)

Afecto , Trastornos del Conocimiento/diagnóstico , Aprendizaje por Laberinto/fisiología , Serotonina/fisiología , Factores de Edad , Animales , Conducta Animal , Trastornos del Conocimiento/epidemiología , Modelos Animales de Enfermedad , Masculino , Ratas

RESUMEN

Maternal thiamine deficiency causes changes in cellular energy metabolism that can interfere with offspring brain development. The purpose of the present study was to investigate the effects of thiamine restriction, during lactation, on offspring neurochemistry and cognitive parameters. Male young (31 days old) and adult (75 days old) rats, from control and restricted mothers, were submitted to spatial learning and memory assessment. GABAergic and glutamatergic parameters were measured in thalamus, prefrontal cortex and hippocampus by high performance liquid chromatography (HPLC). The young animals were assessed immediately after thiamine restricted period; the adults, however, underwent a recovery period of 45 days. In young rats, thiamine restriction significantly hindered body weight gain and learning speed; however, it did not affect the brain weight, GABA and glutamate parameters in any of the brain assessed areas. In adult rats the body weight gain was significantly hampered by thiamine restriction, while brain weight and spatial task were not affected. Also, in adult offspring, maternal thiamine restriction significantly decreased the glutamate and GABA contents in the three assessed brain areas and thalamus, respectively. One possible explanation for these findings is that an adjustment of the inhibitory (GABAergic) and stimulatory (glutamatergic) neuromodulation systems occurs, in order to reverse the behavioral deficits detected in young rats but not in adult ones. The present data show, for the first time, that maternal thiamine restriction during lactation induces cognitive impairments and neurochemical changes in offspring, corroborating the important role of thiamine in brain development.

Asunto(s)

Animales Lactantes/crecimiento & desarrollo , Encéfalo/crecimiento & desarrollo , Trastornos del Conocimiento/etiología , Lactancia/metabolismo , Deficiencia de Tiamina/complicaciones , Tiamina/metabolismo , Análisis de Varianza , Animales , Animales Lactantes/metabolismo , Encéfalo/metabolismo , Trastornos del Conocimiento/metabolismo , Metabolismo Energético , Femenino , Ácido Glutámico/metabolismo , Hipocampo/crecimiento & desarrollo , Hipocampo/metabolismo , Masculino , Aprendizaje por Laberinto/fisiología , Leche/química , Leche/metabolismo , Valor Nutritivo , Corteza Prefrontal/crecimiento & desarrollo , Corteza Prefrontal/metabolismo , Ratas , Tiempo de Reacción/fisiología , Tálamo/crecimiento & desarrollo , Tálamo/metabolismo , Tiamina/análisis , Deficiencia de Tiamina/etiología , Factores de Tiempo , Ácido gamma-Aminobutírico/metabolismo

RESUMEN

The purposes of the present study were to verify the effects of a severe thiamine deficiency episode on spatial cognitive aspects and thalamic serotonergic parameters. The animals were submitted to a severe thiamine deficiency treatment that was interrupted after the onset of the last neurological signs. The results obtained confirm previous findings about TD deficiency effects on cognitive function and, further show that this vitamin increases the thalamic serotonine metabolite, 5-hidroxyindolacetic acid (5-HIAA), level. In addition, the present data shed light on the importance of this metabolite in spatial cognitive function.

Asunto(s)

Ácido Hidroxiindolacético/metabolismo , Trastornos de la Memoria/metabolismo , Serotonina/metabolismo , Percepción Espacial/fisiología , Tálamo/metabolismo , Deficiencia de Tiamina/metabolismo , Análisis de Varianza , Animales , Masculino , Aprendizaje por Laberinto/fisiología , Trastornos de la Memoria/etiología , Pruebas Neuropsicológicas , Piritiamina , Ratas , Ratas Wistar , Deficiencia de Tiamina/inducido químicamente , Deficiencia de Tiamina/complicaciones , Factores de Tiempo

RESUMEN

A C18 reversed-phase column and isocratic fluorescence HPLC method for the simultaneous detection of glutamate and gamma-aminobutyric acid (GABA) is described. In this article a fast and more efficient method for the extraction of these neurotransmitters in rat brain tissue is also presented. The supernatant was derivatized with o-phthalaldehyde (OPA) and analyzed by HPLC with fluorescence detection. Intraday reproducibility was 97.0% and 96.7% and interday reproducibility was 97.1% and 93.7% for GABA and glutamate, respectively. Recovery assays indicate that the accuracy of the method for GABA is 99.6+/-2.3% and for glutamate is 101.9+/-1.8%. In addition, the time consumed to run a sample is lower than that described by other authors. Mean elution time was 3.10 min and 8.22 min for glutamate and GABA, respectively. Thus, in a total runtime of less than 9 min both neurotransmitters were detected. Moreover, when compared to the current methods, the extraction solution used here allowed a high drawing out of the neurotransmitters, glutamate and GABA, from the hippocampus, thalamus and prefrontal cortex of the rat brain.

Asunto(s)

Química Encefálica/fisiología , Encéfalo/metabolismo , Cromatografía Líquida de Alta Presión/métodos , Ácido Glutámico/análisis , Neuroquímica/métodos , Ácido gamma-Aminobutírico/análisis , Animales , Encéfalo/anatomía & histología , Ácido Glutámico/metabolismo , Masculino , Terminales Presinápticos/metabolismo , Ratas , Ratas Wistar , Reproducibilidad de los Resultados , Transmisión Sináptica/fisiología , Factores de Tiempo , Ácido gamma-Aminobutírico/metabolismo , o-Ftalaldehído/química

RESUMEN

Oxidative stress, selective neuronal loss, and diminished activity of thiamine-dependent enzymes play a role in many neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease and Huntington's disease. To further understand the major implications of thiamine deficiency (TD) in neuronal death, we induced TD during pregnancy and evaluated the effects on the offspring. The body and brain weights of pups from thiamine-deficient dams were significantly smaller than normal. Loss of neuronal viability was examined by trypan blue exclusion assay, and demonstrated increased cytotoxicity in primary cultures of TD neurons. Additionally, cerebellar cultures were exposed to thiamine-free cell culture medium to better explore the effects of thiamine withdrawal. Alterations in potassium current has previously been associated with the development of cell death. In this study, we examined the TD effects on delayed rectifier and A-type K+ channels, two well-known voltage-activated K+ channels involved in the regulation of action potential firing in cerebellar granule neurons. Current recordings were performed in cultured rat cerebellar granule neurons at day 7, using the whole-cell voltage-clamp technique. Our data demonstrate that thiamine deficiency provoked a significant decrease in the voltage-dependent K+ membrane conductance. Finally, TD markedly depressed the transient A-type K+ currents.

Asunto(s)

Cerebelo/anomalías , Trastornos Nutricionales en el Feto/metabolismo , Degeneración Nerviosa/metabolismo , Canales de Potasio con Entrada de Voltaje/metabolismo , Degeneraciones Espinocerebelosas/metabolismo , Deficiencia de Tiamina/complicaciones , Animales , Supervivencia Celular/fisiología , Células Cultivadas , Cerebelo/metabolismo , Cerebelo/fisiopatología , Femenino , Trastornos Nutricionales en el Feto/fisiopatología , Potenciales de la Membrana/efectos de los fármacos , Potenciales de la Membrana/fisiología , Degeneración Nerviosa/etiología , Degeneración Nerviosa/fisiopatología , Neuronas/metabolismo , Neuronas/patología , Estrés Oxidativo/fisiología , Técnicas de Placa-Clamp , Embarazo , Complicaciones del Embarazo/metabolismo , Complicaciones del Embarazo/fisiopatología , Ratas , Ratas Wistar , Degeneraciones Espinocerebelosas/etiología , Degeneraciones Espinocerebelosas/fisiopatología , Tiamina/metabolismo , Deficiencia de Tiamina/fisiopatología

RESUMEN

A study was conducted to compare health status of male adult Wistar rats from two Experimental Animal Houses of UFMG with literature data of SPF (free from specific pathogens) and conventional rats. The animals were divided into two groups: Group I (n=10), rats from the experimental animal houses of FAFICH and Group II (n=10) from ICB and following aspects were studied: a) evident clinical signs (behavior modification, hair loss (alopecia), b) leukocyte counts, c) feces exam and d) histological study of the lungs. The rats did not show clinical signs. However, when compared with SPF and conventional rats, both the groups showed a significant increase (p<0,05) of leukocyte count. On feces exam we detected some parasites and on lung histological exam we observed fungus (Group I) and bacteria (Group II). These results showed that the health status of the rats was not satisfactory and required improvements in the conditions of the animal houses

Asunto(s)

Animales , Técnicos de Animales , Animales de Laboratorio , Estudios de Casos y Controles , Infecciones , Recuento de Leucocitos , Organismos Libres de Patógenos Específicos , Enfermedad , Ratas Wistar , Signos y Síntomas

RESUMEN

Considerando a necessidade de investigar a prática educativa do educador de creche para a promoção da integração das crianças com necessidades educativas especiais, o presente estudo teve como objetivo: descrever as situações de interações ocorridas durante a prática educativa do educador de creche; e avaliar os efeitos do treinamento em serviço. Quatro educadores de creche participaram em um delineamento quase experimental de sujeitos com seu próprio controle, conduzindo em três fases: linha de base, treinamento e follow-up. Os resultados mostraram diferenças significativas, apontando um aumento no número de episódios interativos efetivos, favorecendo a integração sócio-educativa da criança especial. Comprovam, assim o efeito positivo do treinamento na modificação da prática educativa, visando uma melhor qualidade educacional e garantia da integração(AU)

Asunto(s)

Preescolar , Guarderías Infantiles/educación , Educación Especial

RESUMEN

In this article we outline the use of experimental animal models to study aspects of memory processes. We describe some results obtained by our group and other laboratories in studies on memory aspects, using rats chronically treated with alcohol. At behavioral and biochemical levels, we focused respectively, on retrograde amnesia and central nervous cholinergic system. We also compare, at both levels, the direct and indirect (those related to thiamine deficiency) effects induced by chronic alcohol treatment.

Asunto(s)

Animales , Ratas , Colinérgicos , Alcoholismo , Conducta Animal , Memoria , Sistema Nervioso/fisiopatología , Amnesia Retrógrada , Enfermedad Crónica

Asunto(s)

Sulfanilamidas/metabolismo , Química