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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

Dor pélvica crônica de origem não visceral: caracterização da amostra, avaliação da excitabilidade cortical e resultado do tratamento com sessão única de estimulação magnética transcraniana do córtex motor / Non-visceral origin chronic pelvic pain: sample characterization, assessment of cortical excitability and result of treatment with single session of transcranial magnetic stimulation of the motor cortex

Telma Regina Mariotto Zakka 14 April 2015 (has links)
INTRODUÇÃO: A dor pélvica crônica não visceral constitui desafio clínico, justificável pela diversidade de estruturas presentes na pelve e pelo amplo arcabouço musculoesquelético que a envolve, sustenta e protege, o que dificulta seu diagnóstico e tratamento. Várias são as causas de sua ocorrência e vários sistemas orgânicos podem estar nela envolvidos, isolada ou associadamente, incluindo-se especialmente o geniturinário, o gastrointestinal, o neuropsicológico e o musculoesquelético. OBJETIVOS: Caracterizar-se clínica e demograficamente uma amostra composta de mulheres com dor pélvica crônica de origem não visceral refratária ao tratamento convencional e avaliar-se do efeito analgésico da estimulação magnética transcraniana repetitiva (EMTr) na magnitude da dor, psiquismo, função sexual e qualidade de vida. CASUÍSTICA E MÉTODOS: Dezoito doentes foram aleatorizadamente incluídas em dois grupos (A e B) de estudo para receber tratamento inicial com EMTr ativa (EMTr-a) ou EMTr sham (EMTr-s) respectivamente, aplicadas na área de representação da pelve e períneo do córtex motor primário. EMTr-a foi realizada com a frequência de 10Hz; 80% do limiar motor de repouso totalizando 3000 pulsos por sessão. A EMTr-s foi realizada com uma bobina desconectada e uma segunda bobina ativa aplicada perpendicularmente à primeira e ligada de modo a emitir sons e reverberações sobre o escalpo semelhantes ao da EMTr. Três semanas após a sessão de EMTr-a, as doentes do grupo A foram tratadas com EMTr-s e as do grupo B com EMTr-a. As avaliações foram realizadas no momento basal (D-7), e nos dias, -1, +7, + 21, +28 e +36 do início do estudo. Foram utilizados os seguintes inventários validados para a língua portuguesa: Inventário Breve de Dor; DN-4, Questionário de descritores breve de dor McGill, Inventário de Sintomas de Dor Neuropática, Escala Hospitalar de Ansiedade e Depressão, Índice da Função Sexual Feminina, WHOQOL-breve, Escala Visual Analógica e Questionário para Avaliação da Dor Pélvica e um algiometro para avaliar a sensibilidade dolorosa muscular na pelve e quadril. RESULTADOS E CONCLUSÕES: A DPC era intensa, havia escores elevados de ansiedade e depressão, a dor causou impacto negativo nas atividades físicas e diárias, na autopercepção do estado de saúde, na função sexual feminina e na qualidade de vida e houve elevada ocorrência da síndrome dolorosa miofascial nos músculos pélvicos e do quadril. A EMTr-a proporcionou melhora significativa da dor nas doentes tratadas inicialmente com EMTr-a e a EMTr-s causou melhora significativa e menos marcante da dor quando foi precedida do tratamento com a EMTr-a. Não houve modificação significativa dos valores dos escores de depressão e ansiedade e dos valores dos escores do Índice da Função Sexual Feminina nas doentes inicialmente tratadas com EMTr-a e ocorreu aumento do valor do escore ansiedade nas doentes inicialmente tratadas com EMTr-s. Houve aumento dos valores dos domínios \"psicológico\" e \"meio ambiente\" do WHOQOL-breve nas doentes tratadas inicialmente com EMTra. O resultado do tratamento inicial com EMTr-a ou EMTr-s influenciou o resultado do segundo procedimento. O limiar motor em repouso estava elevado, a inibição intracortical reduzida e a facilitação intracortical normal. Houve correlação entre o limiar motor de repouso e o maior número de descritores afetivos do Questionário de Dor McGill e entre a redução da inibição intracortical e o número aumentado de descritores afetivos do mesmo questionário. A estimulação magnética transcraniana repetitiva é procedimento seguro e alternativa terapêutica para doentes com DPC / INTRODUCTION: Non-visceral chronic pelvic pain is clinical challenge due to the diversity of structures present in the pelvis and the widespread musculoskeletal framework that surrounds, supports and protects, which makes its diagnosis and treatment very difficult and usually unsatisfactory. Many are its causes and various organs may be involved in its occurrence, either alone or in association, especially the genitourinary, gastrointestinal, musculoskeletal and neuropsychological structures. OBJECTIVES: Clinical and demographic characterization of a sample of women with non-visceral chronic pelvic pain refractory to conventional treatments and evaluation of the analgesic efficacy of repetitive transcranial magnetic stimulation (rTMS) in the magnitude of pain, psychic, sexual function and quality of life. PATIENTS AND METHODS: Eighteen patients were randomly included into two groups (A and B) accordingly the use of active rTMS (rTMS-a) or sham rTMS (rTMS-s), respectively, applied in the representation area of the pelvis and motor cortex perineum primary as the first approach. rTMS-a was performed with 10Hz, 80% of the muscle resting threshold and 3000 pulses per session. s-rTMS was performed with a disconnected coil and a second coil applied perpendicularly to the first one to generate sounds and reverberations on the scalp similar to rTMS-a. Three weeks after the session of rTMS-a the group A patients were treated with rTMS-s and the group B patients with rTMS-a. The evaluations were performed at baseline (D-7), and on days -1, +7, +21, +28 and +36 from the start of the study. The following inventories validated for the Brazilian-Portuguese language were used, Brief Pain Inventory were used; DN-4, Questionnaire brief descriptors of McGill Symptoms Inventory Neuropathic Pain, Hospital Anxiety and Depression Scale, Female Sexual Function Index, WHOQOL-brief, Visual Analogue Scale and the Questionnaire for Assessment of Pelvic Pain. A muscle algometer to assess muscle soreness in the pelvis and hip was also used. RESULTS AND CONCLUSIONS: The DPC was severe, the patients presented high scores of anxiety and depression, pain caused negative impact on physical and daily activities, self-perceived health status, female sexual function and quality of life and there was high incidence of myofascial pain syndrome the pelvic muscles and hip. rTMS-a provided significant improvement of pain in patients initially treated with rTMS-a and rTMS-s resulted in significant but less expressive improvement in pain when it was preceded by treatment with rTMS-a. There was no significant change in the values of the scores of depression and anxiety and of the Female Sexual Function Index in patients initially treated with rTMS-a it and there was an increase in the value of the score anxiety in patients initially treated with rTMS-s. There was improvement of the \"psychological\" and \"environment\" dominions of the WHOQOL-brief in patients initially treated with rTMS-a. The results of initial treatment with rTMS-a or rTMS-s influenced the outcome of the second procedure. The resting motor threshold was high, the intracortical inhibition was reduced, and the intracortical facilitation normal. There was correlation between the resting motor threshold and the affective descriptors of the McGill Pain Questionnaire and between reduced intracortical inhibition and the increased number of affective descriptors of the same questionnaire. rTMS is a safe procedure and therapeutic alternative for patients with DPC
212

Estudo do desenvolvimento morfológico fetal e pós-natal dos sulcos cerebrais / Study of the fetal and post-natal morphological development of the sulci of the brain

Koshiro Nishikuni 12 September 2006 (has links)
O estudo foi realizado através de avaliação de 214 hemisférios cerebrais, de 107 espécimes humanos, com a idade variando desde 12 semanas de gestação até 8 meses pós-natal. A idade gestacional dos fetos foi calculada através do seu peso corpóreo. Os fetos com malformações congênitas ou com encéfalos danificados foram excluídos. Após a fixação do encéfalo em solução de formol a 10%, foi removida a aracnóide para a análise dos sulcos do cérebro, os quais foram então estudados, desde o seu aparecimento, até sua formação completa. A principal finalidade desse estudo foi estabelecer os padrões de desenvolvimento morfológico dos sulcos cerebrais característicos de cada idade gestacional. Tendo como base a análise dos resultados, foram estabelecidas tabelas de referências cronológicas pertinentes à formação de cada sulco em toda superfície do cérebro. / The study was done through the analysis of 214 brain hemispheres of 107 human brains, with their ages ranging from 12 weeks of gestation to 8 months of postnatal life. The gestational age was calculated from their body weight. The fetuses with congenital abnormalities and or damaged brains were excluded from the study. After the brain fixation with 10% formalin, the arachnoid was removed for the study of the sulci and fissures of the brain, since their appearance until their complete development. The aim of this anatomical study was to establish a reliable sulci morphological pattern characteristic of each gestational age. Based in our findings, reference tables pertinent to the appearance of each sulci of all brain surface were built and are here presented.
213

Investigação do dano cortical cerebral e cerebelar em pacientes com doença de Machado-Joseph / Investigation of cortical and cerebellar brain damage in patients with Machado-Joseph disease

Rezende, Thiago Junqueira Ribeiro de, 1988- 24 August 2018 (has links)
Orientadores: Marcondes Cavalcante França Junior, Gabriela Castellano / Texto em português e inglês / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-24T20:36:08Z (GMT). No. of bitstreams: 1 Rezende_ThiagoJunqueiraRibeirode_M.pdf: 1634329 bytes, checksum: 78c3b3cb6bd66174acfe01359a6cb758 (MD5) Previous issue date: 2014 / Resumo: A doença de Machado-Joseph (SCA3/MJD) é a ataxia espinocerebelar mais frequente no mundo, resultante de uma expansão de tripletos CAG no gene MJD1 localizado no cromossomo 14q. Clinicamente ela é caracterizada por danos nos gânglios da base, tronco e cerebelo. Atualmente existem poucos estudos baseados em imagens de ressonância magnética (MRI) que investigam danos no córtex cerebral em pacientes com SCA3/MJD. O objetivo deste estudo foi investigar danos no córtex cerebral na SCA3/MJD usando MRI e correlacionar as possíveis áreas afetadas com dados clínicos, genéticos e neuropsicológicos. Foram recrutados para este estudo 49 pacientes com teste molecular de SCA3/MJD e 49 controles sadios. Os pacientes foram avaliados com a escala de ataxia SARA. Imagens de MR ponderadas em T1 foram adquiridas para todos os voluntários e usadas para a extração das medidas de espessura cortical, realizadas com o software FreeSurfer. O tamanho da expansão CAG médio, SARA e idade de início foram 72,1±4,2, 14,7±7,2 e 37,5±12,5, respectivamente. Os pacientes apresentaram redução de espessura nos córtex precentral e paracentral bem como nos hipocampos e lobos temporal e occipital. Também encontramos redução volumétrica no cerebelo, tálamo, caudado, putamen, globo pálido, tronco e diencéfalo ventral. A gravidade da doença apresentou correlação negativa com a espessura do giro precentral esquerdo (r=-0,302, p=0,035) e com o volume do tronco (r=-0,414, p=0,003). A espessura do giro angular direito apresentou correlação com a duração da doença (r=0,587, p=0,001), mas não com a expansão do tripleto de CAG. O subteste de semelhança de WAIS III apresentou uma correlação com a espessura do sulco central esquerdo (r=0,752, p=0,004) e como o giro occipital superior direito (r=0,704, p=0,016). Estes resultados sugerem que pacientes com SCA3/MJD apresentam dano cortical e subcortical difuso. Os achados estruturais se correlacionaram com as manifestações clínicas da doença, o que apoia a hipótese que a piora nas funções motora e cognitiva e o dano cerebral estão relacionados na SCA3/MJD / Abstract: Machado-Joseph disease (SCA3/MJD) is the most frequent spinocerebellar ataxia worldwide caused by an abnormal expansion of a CAG triplet at the MDJ1 gene located on chromosome 14q. Clinically, it is characterized by brainstem, basal ganglia and cerebellar damage. There are few MRI-based studies that investigated cerebral cortex damage in SCA3/MJD. The objectives of this study are to investigate cerebral cortex damage in SCA3/MJD and to correlate affected areas with clinical, genetics and neuropsychological data. We included 49 patients with molecular confirmation of SCA3/MJD and 49 healthy controls. The scale for assessment and rating of ataxia (SARA) was employed to quantify disease severity. We also performed a comprehensive neuropsychological battery to assess cognitive deficits. Volumetric T1 magnetic resonance images of the brain were acquired for all volunteers and used to calculate cortical thickness measures, performed using the FreeSurfer package. Mean CAG expansion, SARA score and age-at-onset were 72.1±4.2, 14.7±7.2 and 37.5±12.5, respectively. Patients had atrophy at precentral and paracentral cortices as well as the hippocampi, temporal and occipital lobes. We also found volumetric reduction of the cerebellum, thalamus, caudate, putamen, pallidum, brainstem and ventral diencephalon. SARA scores inversely correlated with left precentral gyrus thickness (r=-0.302, p=0.035) and brainstem volume (r=-0.414, p=0.003). Right angular gyrus thickness correlated with disease duration (r=0.587, p=0.001), but not (CAG) expansion. Similarity subscore of WAIS III presented a correlation with thickness of Left central sulcus (r=0.752, p=0.004) and Right superior occipital gyrus (r=0.704, p=0.016). Therefore, patients with MJD/SCA3 have widespread cortical and subcortical atrophy. These structural findings correlate with clinical manifestations of the disease, which support the concept that cognitive/motor impairment and cerebral damage are related in MJD/SCA3 / Mestrado / Fisiopatologia Médica / Mestre em Ciências
214

Aspectos histoquímicos e quantitativos da renutrição precoce e tardia no córtex cerebral de ratos Wistar / Histochemical and quantitative aspects of early and late re-nourishment in the cerebral cortex of Wistar rats

Regina de Sousa Bolina Matos 19 December 2012 (has links)
O objetivo desta pesquisa foi avaliar qualitativa e quantitativamente, através de técnicas histológicas e histoquímicas, o córtex cerebral de ratos submetidos a uma subnutrição protéica e posterior recuperação precoce e tardia. Foram utilizados ratos Wistar submetidos às seguintes dietas nutricionais: dieta padrão - normoprotéica - \"AIN-93G\", contendo 20% de proteína (caseína) e dieta hipoprotéica - \"AIN-93G\", contendo 5% desta mesma proteína, durante os períodos experimentais de 42 e 60 dias. Os grupos experimentais foram formados por animais que desde o acasalamento até a eutanásia foram submetidos à dieta normoprotéica (grupos nutridos N42 e N60) e à dieta hipoprotéica (grupos subnutridos S42 e S60). O grupo renutrido precoce (Rp42) foi constituído por animais subnutridos que, a partir do 22º dia passaram a receber a dieta normoprotéica até 42 dias de idade; animais subnutridos que a partir do 43º dia receberam a dieta normoprotéica até 60 dias de idade, constituíram o grupo renutrido tardio (Rt60). Uma vez formado os grupos experimentais no momento do desmame (21 dias) todos os animais foram alojados e assistidos em gaiolas metabólicas. Características comportamentais e físicas foram avaliadas, bem como os seguintes aspectos morfométricos: pesos corporais e encefálicos; comprimento naso-anal, circunferência abdominal, índice de Lee (que avalia o grau de adiposidade) e as dimensões encefálicas. Para as avaliações quantitativas estruturais foram empregadas técnicas histológicas (H.E. e violeta Cresil) e histoquímica (β-Nicotinamide Adenine dinucleotide phosphate - NADPH) para neurônios nitrérgicos. Foram avaliados parâmetros como: número de neurônios, densidade neuronal, área neuronal e o perfil da área dos neurônios corticais e nas camadas corticais. Em linhas gerais, para os parâmetros aqui avaliados, desde o nascimento até o sacrifício inerente a cada grupo experimental (42 e 60 dias), os animais dos grupos subnutridos (S42 e S60) apresentaram valores menores do que os respectivos grupos controle (N42 e N60), exceto no índice de Lee, significativamente maior do que nos animais nutridos. Os grupos renutridos, independentemente se precoce (Rp42) ou tardio (Rt60) conseguem alguma recuperação em alguns parâmetros avaliados como peso encefálico, dimensões encefálicas e espessura cortical; porém outros como o peso corporal, e a área neuronal foram gravemente afetados. Todavia quando se observa a razão peso encefálico/peso corporal, os animais dos grupos subnutridos relativamente aos animais controles nutridos, apesar do peso corporal menor apresentam uma razão maior do que os respectivos controles, sugerindo ser o encéfalo menos afetado pela subnutrição do que o peso corporal. A subnutrição promoveu acentuada diminuição na área dos neurônios corticais e nitrérgicos, não recuperada com a renutrição, independentemente se precoce ou tardia. Portanto, conforme o proposto e com a metodologia utilizada no presente estudo pesquisa, os resultados permitem concluir que frente às condições de subnutrição, o organismo pode sofrer alterações irreparáveis dependendo do momento da vida em que ocorre, e que a renutrição pode promover recuperação ou mesmo adaptações em alguns parâmetros, preferencialmente se ocorrer em fases mais precoces. / The objective of this study was to evaluate qualitative and quantitatively, through histological and histochemical techniques, the cerebral cortex of rats subjected to protein undernutrition subsequent to early and late recovery. Were used Wistar rats fed with standard (normal) diet-\"AIN-93G\" containing 20% of protein (casein), and hypoproteic diet- \"AIN-93G\" containing 5% of casein during experimental periods of 42 and 60 days. The experimental groups were performed by animals fed with normal diet from mating to euthanasia (nourished groups N42 and N60), and to hypoproteic diet (undernourished groups S42 and S60). The early re-nourished group (Rp42) was composed by undernourished animals fed with normal diet from 22nd day, whereas late re-nourished group (Rt60) was composed by undernourished animals fed with normal diet from 43rd to 60 days of age. Once established the experimental groups at weaning (21 days), all animals were housed and assisted in metabolic cages. Physical and behavioral characteristics were examined, as well as, morphometric aspects: body and brain weight; naso-anal length, abdominal circumference, Lee index (evaluation of fat deposit), and brain measures. For quantitative evaluation, histologic techniques (H.E. and Violet Cresyl), and Histochemistry (β-Nicotinamide Adenine dinucleotide phosphate - NADPH) for nitrergic neurons were performed. The number of neurons, neuronal density, neuronal area and profile of cortical neurons in cortical layers area were analyzed. Animals from S42 and S60 groups shown lower average compared to respective controls (N42 and N60), except in the Lee index, that was significantly higher than in nourished animals. Were observed that re-nourished groups either early (Rp42) or late (Rt60) have recovered in some parameters evaluated such as brain weight, brain measures and cortical thickness; however other parameters like body mass, and neuronal area was highly affected. Relatively to the proportion brain weight/body mass, animals from undernourished group although exhibit low body mass, shown higher proportion than respective control nourished, thus suggesting that brain is less affected by undernutrition than body mass. The undernutrition promoted great decreasing of cortical and nitrergic neurons area; the area was not recovered by early and/or late re-nourishment. In the view of the objectives and methodology used in the present study, we can be conclude that in under-nutrition conditions the body can go through irreversible changes depending on period of occurrence; additionally, re-nourishment can promote recovery or adaptations in some parameters preferentially if occur in early phases.
215

Etude de l'expression du gène EphA7 et de son ligand ephrine-A5 dans le cortex en développement / Transcriptional regulation of EphA7 and ephrin-A5 gene in the developing forebrain

Pietri, Sandra 26 October 2010 (has links)
Le cortex cérébral constitue l’une des structures les plus évoluées et complexes de notre cerveau. Sa surface est divisée en de nombreuses aires fonctionnelles. La mise en place des aires corticales dépend à la fois de facteurs intrinsèques comme la sécrétion de morphogènes ou l’expression en gradient de différents facteurs de transcription, mais elle dépend aussi de facteurs extrinsèques au cortex, en particulier l'innervation par le thalamus. <p>Les ephrines et leurs récepteurs Eph constituent une famille multigénique de facteurs de signalisation impliqués dans divers événements clé du développement cortical où ils sont exprimés selon des profils spatio-temporels complexes. Aux stades tardifs du développement, EphA7 et l’ephrine-A5 sont exprimés en gradients complémentaires au sein de chaque territoire des aires présomptives, constituant ainsi les marqueurs les plus précoces de ces aires corticales. <p>Par la combinaison d’approches in-vitro utilisant la technique d’électroporation focale de tranches corticales embryonnaires, puis in-vivo en utilisant la technique de transgénèse d’addition, nous avons identifié une séquence régulatrice de EphA7 appelée pA7, capable de mimer l’expression endogène de EphA7 au sein du télencéphale dorsal en développement. La lignée de souris pA7-GFP ainsi générée exprime la GFP spécifiquement au sein du télencéphale dorsal durant les stades précoces. Aux stades périnataux cette expression se régionalise au sein de la plaque corticale de chacune des aires présomptives selon des gradients récapitulant ceux observés pour EphA7. Nous avons ensuite purifié des neurones exprimant différents niveaux d’EphA7 par la technique de FACS «Fluorescence-Activated Cell Sorting » et l’analyse de leur transcriptome nous a permis de trouver un grand nombre de gènes différentiellement exprimés. Tous ceux testés par la technique d’hybridation in situ sont exprimés selon un gradient latéral fort et médial faible dans le cortex pariétal, similaire à celui d’EphA7. L’examination de leur profil au sein de cortex de souris dépourvus d’afférences thalamiques, nous a permis de conclure que l’expression de ces gènes incluant EphA7 s’établit indépendamment de celles-ci. Ainsi, notre étude a permis d'identifier un répertoire de gènes neuronaux, pouvant agir en amont ou en combinaison avec EphA7 pour contrôler les facteurs intrinsèques essentiels à l’établissement des aires corticales./<p>The cerebral cortex is subdivided into distinct cortical areas characterized by specific patterns of gene expression and neuronal connectivity. The patterning of cortical areas is thought to be controlled by a combination of intrinsic factors that are expressed in the cortex, and external signals such as inputs from the thalamus. EphA7 is a member of the ephrin/Eph family of guidance factors that is involved in key aspects of the development of the cortex, and is expressed in several gradients within developing cortical areas. <p>By combining in vitro transcriptional assays and mouse transgenics, we identified a regulatory element of the EphA7 promoter, named pA7, that can recapitulate salient features of the pattern of expression of EphA7 in the developing forebrain, including gradients in the cortex. Using a mouse reporter line where GFP expression recapitulates EphA7 expression, we developed a GFP-based cell sorting procedure to isolate cortical neuron populations displaying different levels of EphA7 expression. Transcriptome analysis of these populations enabled to identify a specific array of differentially expressed genes. All genes validated further in vivo were confirmed to be expressed along distinct gradients in the developing cortical plate, similarly to EphA7. The expression of these genes was unchanged in mutant mice defective for thalamocortical projections, indicating that their graded pattern is largely intrinsic to the cortex. Our study identifies a novel repertoire of cortical neuron genes that may act upstream of, or together with EphA7, to control the intrinsic patterning of cortical areas. <p> <p> / Doctorat en Sciences biomédicales et pharmaceutiques / info:eu-repo/semantics/nonPublished
216

Rôle de l'acide rétinoïque dans la neurogenèse corticale chez la souris / Role of retinoic acid during mouse cortical neurogenesis

Haushalter, Carole 28 September 2016 (has links)
L’acide rétinoïque (AR), dérivé actif de la vitamine A (rétinol) circulante, est une petite molécule lipophile contrôlant divers aspects de la mise en place du système nerveux central des vertébrés. L'AR influence notamment le développement précoce du cerveau antérieur, où il contrôle la prolifération et la survie des cellules progénitrices dans l'épithélium neural prosencéphalique. Le développement neural est un processus qui s'articule en trois grandes étapes : la phase d'expansion latérale (E9,5-E10,5 chez la souris), la phase de neurogenèse (E11,5-stades périnataux) et la phase de gliogenèse (stades périnataux-adulte). Nous avons montré que l'AR produit par les méninges à partir de E13 influence la spécification et la migration neuronale au cours de la phase de neurogenèse. De plus, nos travaux suggèrent un rôle plus précoce de l'AR pour la formation et la prolifération des populations progénitrices et neuronales avant et au début de la phase de neurogenèse. Une combinaison de signaux intrinsèques et extrinsèques contrôle divers aspects du développement neural cortical. Nos travaux placent l'AR parmi ces facteurs modulateurs de la neurogenèse corticale. / Retinoic acid (RA), an active vitamin A (retinol) metabolite, is a small lipophilic molecule controlling numerous events during central nervous system development in vertebrates. RA is involved in early forebrain development by controlling cell proliferation and survival in the prosencephalic neuroepithelium. Neural development is a process progressing through three key steps: a phase of lateral expansion (E9.5-E10.5 in the mouse), a phase of neurogenesis (E11.5-perinatal stages) and a gliogenic phase (perinatal stages-adult). My work has shown that RA produced by the developing meninges from E13 influences neuronal specification and migration during the phase of neurogenesis. Moreover, our data suggest an earlier role of RA during the production and proliferation of progenitor and neuronal populations, before and at the onset of the neurogenic phase. A combination of extrinsic and intrinsic signals is required to orchestrate the various aspects of cortical development. RA is likely to be one of such extrinsic factors modulating cortical neurogenesis.
217

Avaliação do sistema purinérgico e colinérgico em córtex de ratos após hipóxia-isquemia neonatal / Evaluation of purinergic and cholinergic system in the cerebral cortex of rats after neonatal hypoxia-ischemia

Pimentel, Victor Camera 15 March 2013 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Hypoxia-ischemia (HI) neonatal is a major cause of morbidity and mortality during the perinatal period and it is an important risk factor for the development of a number of human neurological disorders, such as cerebral palsy, epilepsy, and motor and learning deficits. Cerebral HI results in hemodynamic, biochemical and neurophysiological alterations as a direct consequence of the lack of oxygen and glucose. The central nervous system presents a relatively high consumption of oxygen and glucose which relies almost exclusively on the oxidative phosphorylation process for the production of energy thus it is highly susceptible to hypoxic-ischemic insult. During the HI event, the rapid suppression in the process of oxidative phosphorylation initiates a series of poisonings that occur simultaneously and are directly related to the evolution of brain injury. Thus, knowing that the pathogenesis of neonatal HI is a highly complex and multifactorial event, this study aimed to investigate possible changes in the purinergic and cholinergic systems in the cerebral cortex of newborn rats subjected to HI, at different post-insult (immediately, 72 h and 8 days after neonatal HI),. Furthermore, analyzes were performed to assess the levels of lipid peroxidation and some peripheral markers of inflammation such as tumor necrosis factor alpha TNF-α; Interferon-gamma - IFN-γ; interleukins IL-1β and IL-6. Results demonstrated that immediately after HI, the activity of nucleotide triphosphate diphosphohydrolase (NTPDase) and 5 '-nucleotidase (5`-NT) cytosolic increased in the cerebral cortex. In synaptosomes, an increase in the activity of ecto-adenosine deaminase (ecto-ADA) was observed, while the activity of Na+/K+ ATPase was inhibited. There was no change in the expression of adenosine kinase (ADK). Interestingly, the Na+/K+ ATPase activity was correlated negatively with the cytosolic NTPDase activity and TBARS content. Our results showed an increase in lipid peroxidation levels immediately, 72 h and 8 days after HI. The activity of acetylcholinesterase (AChE) showed time-dependent changes in the cerebral cortex of these animals. The same was observed for AChE activity in erythrocytes and ADA. Regarding the levels of proinflammatory cytokines (TNF-α, IFN-γ, IL-1β and IL-6) investigated, all showed increased serum levels. Immediately after HI, the ADA activity showed a strong positive correlation with all cytokines analyzed. Eight days after HI there was an inflammatory process with increased activity of ADA, myeloperoxidase (MPO) and N-acetyl-glucosaminidase (NAG). In this same period, we observed that ADA1 isoenzyme was responsible for the increase in the ADA activity after HI insult. Interestingly, adenosine receptors A1 (A1Rs) and ADK protein expression showed a decrease 8 days after insult. Thus, the results described here suggest that neonatal HI alters the cholinergic and purinergic signaling in the cortex of newborn rats. However, the understanding of these events may help in the development of new therapies for hypoxic-ischemic brain injury. / A hipóxia-isquemia (HI) neonatal é uma das principais causas de morbidade e mortalidade durante o período perinatal, constituindo um fator de risco importante para o desenvolvimento de uma série de desordens neurológicas em humanos tais como, a paralisia cerebral, a epilepsia e déficits motores e de aprendizagem. A HI cerebral resulta em alterações hemodinâmicas, bioquímicas e neurofisiológicas como uma consequência direta da falta de oxigênio e glicose. O sistema nervoso central por possuir um consumo relativamente alto de oxigênio e glicose, dependendo quase que exclusivamente do processo de fosforilação oxidativa para a produção de energia, torna-se altamente suscetível ao insulto hipóxico-isquêmico. Durante o evento HI, a rápida supressão no processo de fosforilação oxidativa inicia uma série de eventos tóxicos que ocorrem simultaneamente e estão diretamente relacionados com a evolução da lesão cerebral. Assim, sabendo que a patogênese da HI neonatal é um evento multifatorial e altamente complexo, este trabalho teve como objetivo principal investigar, em diferentes tempos pós-insulto (imediatamente, 72 horas e 8 dias após a HI neonatal), as possíveis alterações nos sistemas purinérgico e colinérgico em córtex cerebral de ratos neonatos submetidos à HI. Além disso, foram realizadas análises para avaliar os níveis de peroxidação lipídica e marcadores periféricos de inflamação tais como o fator de necrose tumoral alfa (TNF-α), o interferon gama (IFN-γ) e as interleucinas 1β e 6 (IL-1β e IL-6, respectivamente). Os resultados demonstram que imediatamente após a HI a atividade da nucleotídeo trifosfato difosfoidrolase (NTPDase) e da 5`-nucleotidase (5`-NT) citosólicas aumentaram no córtex cerebral. Em sinaptossomas houve um aumento na atividade da ecto-adenosina desaminase (ecto-ADA), enquanto a atividade da Na+/K+ ATPase mostrou-se reduzida. Não foi observada nenhuma alteração na expressão da adenosina quinase (ADK). Interessantemente, a atividade da Na+/K+ ATPase correlacionou-se negativamente com a atividade da NTPDase citosólica e com os níveis de peroxidação lipídica. Nossos resultados demonstraram um aumento nos níveis de peroxidação lipídica imediatamente após o insulto, os quais foram mantidos 72 horas e 8 dias após a HI. A atividade da acetilcolinesterase (AChE) mostrou alterações tempo-dependente no córtex cerebral destes animais. O mesmo foi observado para a atividade da AChE e da ADA em eritrócitos. Quando os níveis das citocinas pró-inflamatórias (TNF-α; IFN-γ; IL-1β e IL-6) que foram investigadas, todas apresentaram seus níveis séricos aumentados. Imediatamente após a HI, a atividade da ADA apresentou uma forte correlação positivas com todas as citocinas analisadas. 8 dias após a HI observou-se um processo inflamatório com aumento da atividade da ADA, mieloperoxidase e N-acetil-β-D-glucosaminidase. Neste mesmo período, podemos evidenciar que a ADA1 é a isoenzima responsável pelo aumento da ativada da ADA neste momento pós-insulto. Interessantemente, observamos uma redução na expressão dos receptores de adenosina A1 (A1Rs) sem alteração na expressão da adenosina quinase (ADK). Assim, os resultados descritos aqui sugerem a HI neonatal altera a sinalização purinérgica e a atividade da acetilcolinesterase em córtex cerebral de ratos neonatos. Além disso, possibilitará uma melhor compreensão dos eventos que se inciam com o evento HI, e consequentemente auxiliaram na busca e desenvolvimento de novas terapias para a lesão cerebral hipóxico-isquêmica.
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Connectivity and Processing in the Macaque Cerebral Cortex / Connectivité et traitement de l'information dans le cortex cérébral du macaque

Gariel, Marie-Alice 11 January 2017 (has links)
Pour comprendre comment le cortex cérébral extrait du sens et produit des actions à partir des informations sensorielles, il est nécessaire de comprendre à la fois son architecture et ses états dynamiques. Dans la présente thèse nous avons abordé cette relation structure-fonction au niveau des aires cérébrales, leurs connections et leurs interactions au sein du réseau cortical. Les aires sont connectées entre elles par deux grands types de projections axonales. D'une part, les connections « feedforward » (littéralement « antéroactives ») transmettent l'information des aires sensorielles aux aires de plus haut niveau dans la hiérarchie corticale et dont l'activité sous-tend des représentations plus abstraites. À l'inverse, les connections feedback (rétroactives) relient des aires dans la direction descendante de la hiérarchie corticale, vers les aires sensorielles primaires. Pour explorer les rôles respectifs des connections feedforward et feedback nous avons utilisé une triple approche. Premièrement, nous avons mis en évidence une asymétrie fonctionnelle très nette entre propagation feedforward et feedback grâce à des enregistrements et de la microstimulation électrique dans les aires V1 et V4 de macaques en comportement. D'autre part, nous avons étudié les propriétés globales du réseau cortical grâce à une riche base de données de connectivité basée sur des injections de traceurs fluorescents, et décrit une propriété générale et fondamentale de l'organisation corticale. Enfin, nous avons combiné des propriétés anatomiques des aires corticales et les données de connectivité dans un modèle dynamique à grande échelle du cortex / To understand how the cerebral cortex does what it does, it is necessary to elucidate both how its dynamic states are correlated with the functions it performs, and how it is organised. Many functional and anatomical gradients have been described that reflect the hierarchical abstraction at the heart of cortical computation. It was showed that two flavours of cortical connections exist, and that in the visual cortex they happen to transport information in opposite directions along this gradient. It was also hypothesised that other modalities exhibit the same type of gradient in their respective domains. However, studying requires knowledge of the architecture at different levels (such as the cortical column) and a causal understanding of the functional properties of these types of connections. First, we have studied the dynamics of both feedforward and feedback propagation in the visual system of awake, behaving macaque monkeys. Using the causal method of electrical microstimulation and recording, we have found a dynamic signature of each type of projections and an asymmetry in the way each type of input interacts with ongoing activity in a given visual area. Secondly, thanks to a rich and systematic data set in the macaque, we have found a fundamental organisational principle of the embedded and weighted cortical network that holds also in the more detailed level of neuronal connections inside an area. Finally, we have combined known anatomical gradients with actual inter-areal connectivity into a dynamic model, and here we show how it relates to both the ordering of areas along a hierarchical gradient and the wiring diagram of the cortical network
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Etude expérimentale et théorique de la genèse des potentiels de champs locaux par les neurones corticaux / Experimental and theoretical study of the genesis of local field potentials by cortical neurons

Gomes, Jean-Marie 17 September 2015 (has links)
Les potentiels de champs locaux (LFP) sont des événements de fréquence inférieure à 200-500 Hz, résultant de l'activité cérébrale. Leur signification et les mécanismes contribuant à leur formation sont encore très débattus. Ainsi, l'existence et l'importance d'un filtrage des courants ioniques par le tissu cérébral est controversée. Certains auteurs concluent que le milieu est résistif, alors que d'autres suggèrent que le tissu cérébral pourrait exercer un filtrage passe-bas significatif sur les courants électriques. Une méthode de mesure nouvelle est présentée ici, s'appuyant sur le concept d'impédance naturelle, mesurée en utilisant un neurone comme " électrode " . Ceci permet d'obtenir l'impédance la plus pertinente d'un point de vue physiologique, en termes d'interface électrode-milieu, d'intensité des courants et d'échelle spatiale. L'impédance mesurée est stable, reproductible, plus forte que celle mesurée traditionnellement, et possède une dépendance en fréquence en 1/vf. Un modèle physique prenant en compte la diffusion ionique dans le milieu est capable de reproduire cette impédance. Une méthode similaire permet de calculer la fonction de transfert entre les potentiels intra- et extracellulaire d'un neurone. Des modèles sont proposés pour expliquer sa forme, prédire les LFP d'après l'activité cellulaire et vice-versa. Ces résultats pourraient aider à l'interprétation des signaux de LFP et d'électroencéphalographie, permettant une compréhension plus profonde du fonctionnement cérébral physiologique et pathologique. / Local field potentials (LFPs) are low-frequency (< 200-500 Hz) events resulting from brain activity. Their meaning and the mechanisms shaping them have been highly debated for decades. The existence and importance of a frequency-dependant filtering of ionic currents by brain tissue is controversial. Some authors conclude that the medium is resistive, while others suggest that brain tissue may exert significative low-pass filtering on electrical currents. A new measurement method is presented here, relying on the concept of natural impedance, which is measured using a neuron as an ''electrode''. This allows to obtain the most relevant impedance from a physiological point of view, in terms of electrode-medium interface, current intensity and spatial scale. The measured impedance is stable, reproducible, stronger than what is traditionally measured, and has a 1/\√f frequency dependance. A physical model, taking into account ionic diffusion in the medium, is able to reproduce this impedance. A similar method allows to compute the transfer function between the intra- and extracellular potentials of a neuron. Models are proposed to explain its structure, predict LFPs from cell activity and vice-versa. These results may help interpreting LFP and electroencephalography signals, yielding a deeper understanding of the physiological and pathological brain function.
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Efeitos da estimulação transcraniana por corrente contínua associada ao treino de mobilidade com realidade virtual sobre o equilibrio estático e funcional de crianças com paralisia cerebral: ensaio clínico controlado aleatorizado, duplo cego / Effects of transcranial direct current stimulation associated with virtual reality training on balance in children with cerebral palsy: a randomized controlled, double-blind trial

Lazzari, Roberta Delasta 26 February 2015 (has links)
Submitted by Nadir Basilio (nadirsb@uninove.br) on 2016-05-25T18:06:07Z No. of bitstreams: 1 Roberta Delasta Lazzari.pdf: 2200811 bytes, checksum: 37290c6b343d6e2ca53090aceb0d4682 (MD5) / Made available in DSpace on 2016-05-25T18:06:07Z (GMT). No. of bitstreams: 1 Roberta Delasta Lazzari.pdf: 2200811 bytes, checksum: 37290c6b343d6e2ca53090aceb0d4682 (MD5) Previous issue date: 2015-02-26 / Purpose: To investigate the effects of transcranial direct current stimulation in the primary motor cortex, associated with mobility training with virtual reality on the static and functional balance of children with cerebral palsy (CP). Materials and Methods: The population sample that was part of this project consisted of 24 children with CP between 4 and 12 years old. The children were divided randomly into two groups (control group: mobility training with virtual reality and use transcranial stimulation placebo; Experimental Group: mobility training using virtual reality and transcranial stimulation active) and evaluated at four different times (pre -intervention, immediately after the first session, after the intervention and one month after intervention). The static balance was evaluated by force platform in four conditions: feet flat on the platform with open eyes, feet on the platform with eyes closed, feet in the open foam eyes, feet foam eyes closed for 30 seconds each. The Functional Balance was measured by Pediatric Balance Scale(PBS) and Timed Up and Go(TUG). Results: The analysis of the immediate effect of treatment with transcranial Direct Current Stimulation (tDCS) only sway velocity showed a significant interaction. In the analysis of the effects of the training area, Center of Pressure (COP) speed and frequency presented significatia interaction as well as the EEP and TUG Conclusion: It is suggested that tDCS interferes with the static and functional balance of children with CP. / Objetivo: Verificar os efeitos da estimulação transcraniana por corrente contínua no córtex motor primário, associada ao treino mobilidade com realidade virtual sobre o equilíbrio estático e funcional de crianças com paralisia cerebral (PC). Materiais e Métodos: A amostra populacional que fez parte deste projeto foi composta de 24 crianças com PC entre 4 e 12 anos de idade. As crianças foram alocadas aleatoriamente em dois grupos (Grupo Controle: treino de mobilidade com uso de realidade virtual e estimulação transcraniana placebo; Grupo Experimental: treino de mobilidade com o uso de realidade virtual e estimulação transcraniana ativa) e avaliadas em quatro momentos distintos (pré-intervenção,imediatamente após a primeira sessão, pós-intervenção e um mês após as intervenções). O equilíbrio estático foi avaliado através da plataforma de força em quatro condições: pés apoiados na plataforma com olhos abertos, pés na plataforma com olhos fechados, pés na espuma olhos abertos, pés espuma olhos fechados, por 30 segundos cada. O Equilíbrio Funcional foi medido por meio da Escala de Equilíbrio Pediátrica (EEP) e Timed Up and Go (TUG). Resultados: Na Análise do Efeito imediato do tratamento com Estimulação Transcraniana por Corrente Contínua(ETCC) somente a velocidade de oscilação apresentou interação significativa. Já na análise dos efeitos do Treinamento a área, velocidade e frequência do Centro de Pressão (CoP) apresentaram interação significatia, bem como o EEP e TUG Conclusão: Sugere-se que a ETCC interfere sobre o equilíbrio estático e funcional de crianças com PC.

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