Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.

Diss. (sammanfattning) Umeå : Univ., 2004. / Härtill 5 uppsatser.

Thesis (Ph.D.)--Medical University of Ohio, 2005. / "In partial fulfillment of the requirements for the degree of Doctor of Philosophy in Medical Sciences." Major advisor: L. John Greenfield, Jr. Includes abstract. Document formatted into pages: iv, 208 p. Title from title page of PDF document. Bibliography: pages 55-62,94-99,137-143,166-206.

Thesis (Ph.D.)--Medical University of Ohio, 2006. / "In partial fulfillment of the requirements for the degree of Doctor of Philosophy in Medical Sciences." Major advisor: Elizabeth I. Tietz. Includes abstract. Document formatted into pages: iv, 234 p. Title from title page of PDF document. Bibliography: pages 86-95,126-135,167-174,190-232.

Thesis (Ph.D.)--University of Florida, 2005. / Typescript. Title from title page of source document. Document formatted into pages; contains 165 pages. Includes Vita. Includes bibliographical references.

Orientador: Iscia Teresinha Lopes Cendes / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-23T06:36:18Z (GMT). No. of bitstreams: 1 Gonsales_MarinaCoelho_D.pdf: 5961380 bytes, checksum: 501b9df1659eb15a6a8545ae0943d967 (MD5) Previous issue date: 2013 / Resumo: As epilepsias são distúrbios cerebrais caracterizados por uma predisposição persistente para a geração de crises epilépticas, que são interrupções transitórias no funcionamento normal do sistema nervoso. Acredita-se que a maioria das epilepsias relacionadas com idade de inicio precoce possui etiologia presumivelmente genética. Sendo assim, elas representam um grupo para o qual o uso de testes genéticos seria potencialmente benéfico. Os objetivos principais deste trabalho foram: a caracterização das bases moleculares de diferentes formas de epilepsia da infância e da adolescência e a avaliação do potencial dos genes candidatos estudados para a utilização em testes genéticos para fins clínicos. A estratégia empregada foi à triagem de mutações nos seguintes genes: SCN1A, em pacientes com síndromes de Dravet e de Doose; SCL2A1 em pacientes com síndrome de Doose e epilepsias idiopáticas generalizadas (EIGs), especialmente a epilepsia mioclonica juvenil (EMJ); e EFHC1 e GABRA1, em pacientes com EMJ e outras formas comuns de EIGs. A triagem de mutações foi realizada por sequenciamento automático pela técnica de Sanger. As alterações potencialmente deletérias foram investigadas em um grupo controle composto por 100 indivíduos sem epilepsia. O potencial deletério das substituições que resultam em troca do resíduo de aminoácido na proteína codificada foi estimado utilizando-se diferentes algoritmos de predição. As mutações previamente descritas na literatura foram compiladas e analisadas quanto a sua provável localização na proteína e predição de efeito deletério. Analises por Multiplex Ligation-dependent Probe Amplification (MLPA) foram realizadas para a detecção de variações no numero de copias de SCN1A. A analise de mutações no gene SCN1A revelou alterações potencialmente deletérias em 81% dos pacientes com síndrome de Dravet, e em apenas um paciente com síndrome de Doose. Esses dados, juntamente com os resultados das analises de compilação das mutações descritas na literatura, sugerem que o teste genético em SCN1A para fins clínicos seria altamente recomendável em indivíduos com síndrome de Dravet, mas não para os com síndrome de Doose típica. O gene SLC21A não parece estar envolvido na etiologia da síndrome de Doose e das EIGs em nossa casuística. A frequencia de alterações potencialmente deletérias no gene EFHC1 em indivíduos com EMJ foi relativamente baixa, sugerindo que esse gene não seja o principal causador dessa epilepsia, embora possa ser um fator de predisposição. Por fim, o gene GABRA1 não parece conferir predisposição para as EIGs comuns em nossa casuística / Abstract: Epilepsy is a brain disorder characterized by a long lasting predisposition to generate epileptic seizures, which are transient interruptions of normal brain function. Most epilepsies with early onset presumably have a genetic etiology. Thus, they represent a group for which the use of genetic testing would be potentially beneficial. The main goals of this study were to characterize the molecular basis of different forms of epilepsy in childhood and adolescence and to evaluate the potential clinical use of genetic testing in the context of these disorders. To achieve these goals we searched for mutations in the following genes: SCN1A in patients with Dravet and Doose syndromes; SLC2A1 in patients with Doose syndrome and idiopathic generalized epilepsies (IGEs), particularly juvenile myoclonic epilepsy (JME); and EFHC1 and GABRA1 in patients with JME and other common forms of IGEs. Mutation screening was performed by automated Sanger sequencing using capillary electrophoresis. Potentially deleterious nucleotide changes found were subsequently investigated in a control group of 100 individuals without epilepsy. In addition, the deleterious potential of amino acid changes identified was estimated using different prediction algorithms. Mutations previously described in the literature were compiled and analyzed regarding their putative location on the protein and predicted deleterious effect. Furthermore, Multiplex Ligation-dependent Probe Amplification (MLPA) analyzes were performed to detect the presence of copy number variations in SCN1A. Our results showed potentially deleterious variants in SCN1A in 81% of patients with Dravet syndrome, but only in one patient with Doose syndrome. These data, along with the results of the compilation of mutations reported in the literature suggest that genetic testing for SCN1A is clinically relevant in Dravet syndrome, but not in typical Doose syndrome. SLC21A does not seem to be involved in the etiology of Doose syndrome and EIGs in our cohort. The frequency of potentially deleterious changes in EFHC1 in individuals with JME was relatively low, suggesting that this gene is not the main cause of this form of epilepsy, although it may be a predisposing factor. Lastly, GABRA1 does not seem to confer predisposition to common EIGs in our cohort / Doutorado / Fisiopatologia Médica / Doutora em Ciências

No description available.

Resveratrol and catechin have behavioral and neuroprotective effects that may be due to their interaction with neuronal ion channels. It was hypothesized that the grape compounds, resveratrol and catechin modulate GABAAA receptors. To address this hypothesis, the effects of resveratrol and catechin were investigated on human recombinant GABAA receptors expressed in HEK-293 cells using electrophysiological techniques.<.p> HEK-293 cells were cultured and transfected using eDNA encoding human GABAA receptors. GABA-evoked currents were recorded from HEK cells 24-48 hours following transfection. Cells were voltage clamped in the whole cell configuration at -60mV using the patch-clamp technique. Ligand-activated currents were recorded and stored, using Win WCP software, on a desktop computer. Resveratrol (1- 100μM) dose-dependently potentiated GABA-evoked currents recorded from α1β2< /sup>γ2 and α1β2 GABAA receptors. Resveratrol did not modulate a α1β2< /sup>γ2 and α1β2 GABAA receptors. Furthermore, resveratrol did not act through the benzodiazepine binding site. The low efficacy and subunit selectivity of resveratrol is a promising discovery for the development of a highly specific GABAergic modulator. Conversely, catechin (1-100αM) dose-dependently inhibited GABA-evoked currents recorded from α1β2 and α1β1 GABAA receptors. The degree of inhibition was the same for both receptor subtypes. Catechin did not modulate α1β2γ2 or α1β1γ2 GABAA receptors. The selectivity of catechin for receptors lacking the γ subunit is similar to the effects of zinc and did not involve the benzodiazephine site on GABAA receptors. This study has shown that catechin and resveratrol are subunit-selective modulators of human GABAA receptors. These compounds could lead to the development of novel agents to be used in treating neurological disorders. These data support the use and study of natural products for the development of agents that act selectively on the nervous system.

No description available.

GABA is the main inhibitory neurotransmitter of the central nervous system. GABA[subscript A]Rs are multimeric transmembrane receptors, which are composed of 5 subunits. It is known that there are 19 subunits that can make up the GABA[subscript A]Rs, allowing for a vast array of receptor subtypes. In addition to the GABA binding site GABA[subscript A]Rs have distinct allosteric binding sites for benzodiazepines, barbiturates, ethanol, certain general anaesthetics and neuroactive steroids. The molecular heterogeneity of the GABA[subscript A]R is accompanied by distinct pharmacological profiles of the different receptor subtypes. The advance of transgenic mouse models has allowed the functional significance of this heterogeneity to be studied in vivo. Therefore, this thesis utilises a variety of transgenic mouse models carrying either mutations or deletions of certain subunits to study the functional significance of the receptor heterogeneity. Mice lacking the α1 subunit (α1[superscript(-/-)]), carrying a point mutation of the α1 subunit (α1H101R), and mice lacking the δ subunit (δ[superscript(-/-)]) have been utilised to investigate the role of these subunits in the sedative actions of benzodiazepines and the GABA[subscript A]R agonist THIP. Although there are limitations to the interpretation of these results due genetic background of the α1[superscript(-/-)] and α1H101R, experiments suggest that the α1H101R mutation is not behaviourally silent as previously suggested and provide further evidence that the α1 subunit mediates the sedative properties of benzodiazepines. These experiments also reveal that the extrasynaptic δ containing receptors are responsible for mediating the sedative effects of THIP, and these findings combined with evidence from collaborators, implicates the thalamus as an anatomical mediator of these effects. An investigation of the putative cognitive enhancing effects of THIP using an attentional set-shifting task for mice suggested that pre-treatment with THIP reduces the number of errors to reach criterion. δ[superscript(-/-)] mice could not be trained to perform the task, therefore further behavioural investigation of these mice was performed, which suggested a heightened level of anxiety and reduced motivation for a food reward. This thesis has furthered our understanding of the functional role of GABA[subscript A]R subtypes. With the advance in genetic manipulations that allow for regionally selective mutations of the receptor the anatomical structures involved in these functions can be identified.