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Disertaciones |
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1
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DAFNE MENDES SOARES
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CATION-CHLORIDE COTRANSPORTERS AND THE GENERATION, SUPRESSION AND SUSTENTATION OF NON-SYNAPTIC EPILEPTIFORM ACTIVITY: COMPUTATIONAL SIMULATIONS
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Líder : ANTONIO MARCIO RODRIGUES
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MIEMBROS DE LA BANCA :
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ANTONIO CARLOS GUIMARAES DE ALMEIDA
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ANTONIO MARCIO RODRIGUES
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DAMIEN THOMAS DEPANNEMAECKER
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GISELE SILVA NOGUEIRA
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Data: 05-mar-2020
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Resumen Espectáculo
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The mechanisms involved in the regulation of chloride homeostasis are intimately related to epileptiform activity. Therefore, studies have been investigating the effect of cation-chloride cotransporters on abnormal neural activity. However, the contribution of these cotransporters to the process of generation and sustentation of epileptiform discharges is not yet clear. This study aimed to investigate the effect of the blockade of cation-chloride cotransporters (KCC and NKCC) on the generation and sustentation of non-synaptic epileptiform activity (NSEA) through mathematical modeling and computational simulations. The mathematical model describes cellular and subcellular electrochemical mechanisms which are typical of the granular layer of the dentate gyrus in the rat hipoccampus, such as ion channels, the Na/K pump, the cotransporters KCC and NKCC, etc. The cotransporters KCC and NKCC, in particular, were represented according to the formalism of Michaelis-Menten, considering the reactions of their physiological ligands in an equilibrium state in each instant. Reproducing experimental procedures, the simulations show that even though the blockage of both cotransporters is not enough to suppress non-synaptic epileptiform discharges after they have been triggered, it is possible to prevent these discharges if the blockade happens before the first one. This makes it possible to hypothesize that drugs that target KCC and NKCC may be used to prevent epileptic seizures.
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2
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ANDREIA RODRIGUES CAMPOS
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EVALUATION OF GLUCOSE METABOLISM DURING NON-SYNAPTIC EPILETIFORM ACTIVITIES - ELECTROPHYSIOLOGY.
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Líder : ANTONIO CARLOS GUIMARAES DE ALMEIDA
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MIEMBROS DE LA BANCA :
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ANTONIO CARLOS GUIMARAES DE ALMEIDA
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CARLA ALESSANDRA SCORZA BAHI
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FULVIO ALEXANDRE SCORZA
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LUIZ EDUARDO CANTON SANTOS
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Data: 05-mar-2020
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Resumen Espectáculo
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Severe epileptic seizures are associated with a significant decrease in ATP concentration. These changes are identified as the cause of clinical sequelae. However, the whole process involved in the course of crises is not yet elucidated. Studies have been focused on the assessment of metabolic conditions necessary for the occurrence of epileptiform activities. Given the importance of glucose in maintaining ideal levels of ATP, therefore acting directly on neuronal metabolic levels, and considering that intense epileptic seizures are sustained in the absence of synaptic connections, the present study aims to investigate the effects of hypoglycemia on seizures. Experiments to induce non-synaptic epileptiform activities were performed with hippocampal slices of wistar rat. Results show suppression of non-synaptic epileptiform activities during hypoglycemic maneuvers. During these maneuvers, a series of tests sought to identify the possible mechanisms responsible for suppression. The data interpretation suggests the suppression of activities induced by hypoglycemia is due to a depolarization block.
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3
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JÚLIA FLÓRIO PIRES DE ANDRADE
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The role of basil (Ocimum basilicum) inflorescences on beneficial arthropods and aphids in associated collard (Brassica oleracea var. acephala) plantations.
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Líder : WELLINGTON GARCIA DE CAMPOS
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MIEMBROS DE LA BANCA :
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LIVIA MENDES DE CARVALHO SILVA
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LUÍS CLÁUDIO PATERNO SILVEIRA
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WELLINGTON GARCIA DE CAMPOS
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Data: 17-mar-2020
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Resumen Espectáculo
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In habitat management for conservative biological control, the vegetation diversification may benefit natural enemies and reduce insect pest populations. This study aimed to assess whether flowering basil (Ocimum basilicum L.) (Lamiaceae), used as an associated plant, increases the abundance of arthropods, especially predators and parasitoids, and reduces aphid (Hemiptera: Aphididae) abundance and infestations in collard (Brassica oleracea L. var. acephala) plantations. Three experimental treatments were carried out, each with two cultivation beds with ten collard plants and ten basil plants: (1) association between collard and flowering basil; (2) association of collard with basil, in which the inflorescences were removed, and (3) collard grown separately. The arthropods were sampled for 10 consecutive weeks, using yellow pan traps, while aphids were sampled by direct counting on collard leaves. The basil inflorescences increased the abundance and number of arthropod families in the system, while the basil without inflorescences did not improve arthropod abundance compared to collards grown alone. Compared to isolated collards, aphid abundance was lower in both combinations of collard and basil, regardless of the presence of inflorescences; however, inflorescences reduced the temporal frequency of aphid population peaks. Although flowering basil increased the abundance of aphid predators in the system, chemical repellents from basil may have been the main factor that reduced population aphids in collards.
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4
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EVELINE ANIELLY CRISTELLI SOARES
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PROSPECTION OF DIAZOTHROPHIC BACTERIA AND PRODUCERS OF PHYTOHORMONES ISOLATED FROM FORAGE GRASSES GENOTYPES.
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Líder : IVANILDO EVODIO MARRIEL
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MIEMBROS DE LA BANCA :
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FREDERICK MENDES AGUIAR
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IVANILDO EVODIO MARRIEL
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ROSANGELA MARIA SIMEÃO
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Data: 28-ago-2020
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Resumen Espectáculo
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Brazil has approximately 180 million hectares of pasture, 85% of the forages being of the genus Urochloa Urochloa (syn. Urochloa), due to its high adaptability to different edaphoclimatic conditions. These plants are also an essential part of integrated agricultural production systems. However, about 70% of these areas are degraded, mainly due to inadequate management, particularly related to nitrogen fertilization. One of the alternatives for the supply of this nutrient in replacement / supplementation of nitrogen fertilizers is the use of diazotrophic bacteria, which perform the biological fixation of N2 (FBN). In view of this context, it was aimed; (i) isolate, characterize and pre-select diazotrophic and non-diazotrophic bacteria, aiming at inoculation of forages, and, (ii) evaluate the growth promotion in plants of Urochloa brizantha cv. Marandu submitted to inoculation with pre-selected bacterial strains. For isolation using samples obtained from rhizospheric soil, root and stem (endophytic) from five genotypes of forage grasses and semi-solid culture medium defined for Azospirillum spp. 156 bacterial isolates were obtained (53% from the root, 30% from rhizospheric soil and 17% stalk) which were incorporated into the Collection of Multifunctional Microorganisms of Embrapa Corn and Sorghum. Based on phenotypic characteristics and growth promotion through the production of indolacetic acid (AIA) and phosphate solubilization, 37 isolates were pre-selected, these were tested for ammonium production and activity of the enzyme ACC deaminase (ACCd). Among these, 30 isolates were tested for molecular characterization, phylogenetic affiliation and for promoting growth and nitrogen incorporation in plants of U. brizantha cv. Marandu. As a result, it was observed that 75% were classified as diazotrophic, 25% as non-diazotrophic, 99.36% as AIA producers, 12.82% phosphorus solubilizers, 100% ammonium producers and 84% with ACCd activity . Analysis of the sequences of the 16S rDNA subunit of bacterial isolates showed high genetic diversity among isolates, with 50% identified as Azospirillum spp., 23% Bacillus spp., 7% Enterobacter, 3% Microbacterium, 7% Serratia, 3% of the genus Stenotrophomonas and 7% of the isolates were not identified. Regarding the growth promotion of cultivar Marandu, it was observed after 90 days of cultivation in a greenhouse, significant variation according to the strains for all tested variables: dry weight of the aerial part (PSPA); dry root weight(PSR); total green weight (PVT); total dry weight (PST); root / shoot ratio; N content in the aerial part. The results allowed the selection of promising strains as candidates for the formulation of specific inoculants for forage grasses.
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Tesis |
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1
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NATANAEL TAVARES DE OLIVEIRA
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MECHANISM OF ACTION OF A BIOSTIMULANT BASED ON HUMIC SUBSTANCE ON THE DEVELOPMENT OF CORN.
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Líder : SYLVIA MORAIS DE SOUSA TINOCO
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MIEMBROS DE LA BANCA :
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SYLVIA MORAIS DE SOUSA TINOCO
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LEONARDO LUCAS CARNEVALLI DIAS
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LUIS WILLIAN PACHECO ARGE
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DANIEL BASILIO ZANDONADI
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CYNTHIA MARIA BORGES DAMASCENO
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Data: 28-feb-2020
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Resumen Espectáculo
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The use of biostimulants has grown in recent years and increased the productivity of important crops such as maizen. Humic substance (SH) biostimulants alter plant metabolism in different ways, but the mechanisms of action are still poorly understood. Therefore, the objective of this work was to identify the mechanisms of action of a commercial leonardite-derived humic acid biostimulant in the growth and development of maize seedlings. Maize plants were grown in nutrient solution with a commercial humic acid biostimulant extracted from leonardite and without the biostimulant (negative control). Initially root and shoot were collected separately, RNA extracted and libraries sequenced on the Illumina HISeq 2500 Paired-End 2x150pb platform generating a total of 264.3 million readings, which 92.8% were mapped in a unique position in the B73 maize reference reference (AGPv4 version). Transcriptomic analysis identified a total of 370 differentially expressed genes (DEGs) in root and 809 in shoots from treated and control plants (FDR <0.05). Overexpressed genes in the root were linked to amino acid and ketone metabolic processes, chitin catabolism, ionic copper and iron transport mechanisms, while overexpressed genes in the shoot were associated with photosynthetic processes, signaling and biosynthesis of different phytohormones. Gene clusters were identified that regulate the same biological functions in both tissues, which are related to protection against different biotic and abiotic stresses, lipid metabolism, synthesis and degradation of cell wall components, biosynthesis of secondary metabolites, nitrate response and transport. On the other hand, the biostimulant suppressed genes related to high light intensity response (photoinhibition), saline stress response and heat response. The ZmLAX3, ZmPIN9 and ZmNRT1.1 genes were also activated when plants were treated with biostimulant. The biostimulant led to an increase in the root surface and consequently to a higher plant dry weight, but there was no change in the macro and micronutrient content. ATPase activity was 2.6-fold higher in biostimulant-treated plants, which also presented higher rhizospheric acidification than the control. In addition, the biostimulant presented high indole-3-acetic acid (AIA) content. Commercial humic
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acid-based biostimulant extracted from leonardite promoted an higher plant growth by increasing the root surface, activating mechanisms related to hormone synthesis, especially AIA, H+-ATPase activity and acidification by proton extrusion ( H+) in the apoplast, which favor cell expansion, increased the expression of nitrate transporters, genes related to secondary metabolism, cell wall and in the shoot increase the expression of photosynthetic genes. Therefore, analysis of gene expression, biochemistry and physiology increased the understanding of the mode of action of humic acid-based biostimulant, and this information may be used in the future to establish regulatory guidelines.
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2
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JOAO PAULO RODRIGUES VIANA
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DIRECT AND INDIRECT MECHANISMS OF THE BASIL (Ocimum basilicum) IN REDUCING THE ATTACK OF HERBIVORES TO ADJACENT PLANTS OF Brassica oleracea.
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Líder : WELLINGTON GARCIA DE CAMPOS
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MIEMBROS DE LA BANCA :
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ANA PAULA MADUREIRA
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LIVIA MENDES DE CARVALHO SILVA
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LUÍS CLÁUDIO PATERNO SILVEIRA
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ROGERIO MARTINS MAURICIO
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WELLINGTON GARCIA DE CAMPOS
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Data: 10-mar-2020
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Resumen Espectáculo
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The use of companion plants in the crop can increase the presence of enemies and indirectly mediate population control of insect pests. These plants can also have a direct repellent effect on undesirable insects. This study discriminated against these mechanisms of basil (Ocimum basilicum) in reducing the attack of Brevycorine brassicae to neighboring plants of Brassica oleraceae. In the field, basil increased the abundance of aphid predators and decreased B. brassicae in adjacent plants. Controlled experiments have shown that basil repels or confuses oviposition of Plutella xylsotella and the choice of the plant by B. brassicae. Its effect repellent, in the absence of natural enemies, generated a population pattern of B. brassicae similar to that observed in the field. A possible role of enemies natural, mediated by basil, was not exclusive in promoting the reduction in abundance of B. brassicae. The repellency or confusion of the herbivore by companion plant had an evident and primordial function. Basil demonstrated potential for use as a companion plant in brassica crops, once that was able to mitigate the attack of B. brassicae, either by indirect effect, via increase in predators, or directly and mainly, by repellency. The use of companion plants in the crop can increase the presence of enemies and indirectly mediate population control of insect pests. These plants also can exercise one It is made repellent direct about insects undesirable. This study discriminated against these mechanisms of basil (Ocimum basilicum) in reducing the attack of Brevycorine brassicae to neighboring plants of Brassica oleraceae. In field, O basil increased The abundance in aphid predators and decreased B. brassicae in adjacent plants. Controlled experiments have shown that basil repels or confuses oviposition of Plutella xylsotella and the choice of the plant by B. brassicae. Its effect repellent, in the absence of natural enemies, generated a population pattern of B. brassicae similar to that observed in the field. A possible role of enemies natural, mediated by basil, was not exclusive in promoting the reduction in abundance of B. brassicae. The repellency or confusion of the herbivore by companion plant had an evident and primordial function. Basil demonstrated potential for use as a companion plant in brassica crops, once that was able to mitigate the attack of B. brassicae, either by indirect effect, via increase in predators, or directly and mainly, by repellency.
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3
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GUILHERME FREDERICO PEDRA PONCIANO
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Useofmodelinput-state-outputforto assessThesustainability of a silvopastoral system
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Líder : FENI DALANO ROOSEVELT AGOSTINHO
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MIEMBROS DE LA BANCA :
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ANTONIO MARCIO RODRIGUES
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FENI DALANO ROOSEVELT AGOSTINHO
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GISELE SILVA NOGUEIRA
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JOAO DOMINGOS SCALON
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MARIO ANTONIO DUARTE
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Data: 20-mar-2020
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Resumen Espectáculo
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The livestock activity has a global economic importance, however it is constantly associated with degradations and environmental impacts. Combining this with the future need to increase productivity to meet consumer demand, assessing the sustainability of these systems is of great importance. In addition to the sustainability assessment, it is interesting to discuss and indicate better ways of handling the system, which in the case of livestock use free inputs provided by nature. This study aims to bring together environmental accounting and emissions inventory methodologies, using the input-state-output model. Environmental accounting was defined as the input parameters of the system, the advantage of this methodology is that it converts all energy flows in the system into a common unit, in addition to quantifying and valuing the natural resources intrinsic to the system. The methodology also provides indexes that summarize the relationships, dependencies, and impacts of the use of inputs. The state of the system was defined as the profitability and the output was estimated as the CO2eq emission from the system, considering the direct emissions from the system and the previous emissions for the generation of the used inputs. The indices of emergy yield rate (EYR), environmental load rate (ELR) and sustainability index (ESI) were used to compose a radar diagram, in order to express the sustainability of the system, regarding the inputs. The proposed sustainability assessment model was applied to a farm (Fazenda Monalisa - FML), located in the legal Amazon region (Brazil) and its management is via agroecological practices, which in livestock can be summarized in silvopastoral management (SPS), which uses vegetation to compose the system, such as hedges, trees scattered in the pasture that serve as a source of shade, in addition to being able to serve as food for the animal reducing the dependence on external inputs. The advantages that the SPS provides for livestock were evidenced mainly by analyzing the radar diagram and comparing it with data from similar systems in the literature. The FML presented an EYR of 2.99, an ELR of 0.53 and an ESI of 5.61, the indices were one of the best found for the livestock system, in the comparisons between the systems and these indices it was possible to verify the positive influences that the portion cause in the system. FML's profitability was 3.17, which is quite satisfactory for this financial activity. The CO2eq emission in the system was 1.72 tons per hectare in the year. In view of all the benefits and influences caused by the plant plot in the system, the net carbon potential was calculated, considering the CO2 absorption potential by the vegetation, the calculations showed the potential that the system has to be a gas mitigator, all thanks to the plant plot that is a fundamental part of the system. The SPS influences on the livestock system are so many that with everything that was discussed in the study it also provided the basis for the discussion on the item biodiversity within environmental accounting.
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4
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RAFAEL SANDIN RIBEIRO
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Enteric methane in tropical conditions: particle size and prediction equations
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Líder : ROGERIO MARTINS MAURICIO
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MIEMBROS DE LA BANCA :
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Adibe Luiz Abdalla
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JOÃO PAULO PACHECO RODRIGUES
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LUIZ GUSTAVO RIBEIRO PEREIRA
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ROGERIO MARTINS MAURICIO
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THIERRY RIBEIRO TOMICH
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Data: 22-abr-2020
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Resumen Espectáculo
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xxxxx
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5
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RAFAEL SANDIN RIBEIRO
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Enteric methane in tropical conditions: particle size and prediction equations
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Líder : ROGERIO MARTINS MAURICIO
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MIEMBROS DE LA BANCA :
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Adibe Luiz Abdalla
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JOÃO PAULO PACHECO RODRIGUES
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LUIZ GUSTAVO RIBEIRO PEREIRA
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ROGERIO MARTINS MAURICIO
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THIERRY RIBEIRO TOMICH
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Data: 22-abr-2020
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Resumen Espectáculo
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xxxxx
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6
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RAFAEL SANDIN RIBEIRO
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EMISSÃO DE METANO ENTÉRICO POR BOVINOS EM CONDIÇÕES TROPICAIS: EFEITO DO TAMANHO DE PARTÍCULAS E EQUAÇÕES DE PREDIÇÃO
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Líder : ROGERIO MARTINS MAURICIO
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MIEMBROS DE LA BANCA :
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Adibe Luiz Abdalla
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JOÃO PAULO PACHECO RODRIGUES
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LUIZ GUSTAVO RIBEIRO PEREIRA
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ROGERIO MARTINS MAURICIO
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THIERRY RIBEIRO TOMICH
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Data: 22-abr-2020
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Resumen Espectáculo
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7
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8
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SAMYRA GIAROLA CECILIO
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INFLUENCE OF CHLORIDE REGULATORY MECHANISMS ONNON-SYNAPTIC EPILEPTIFORM ACTIVITIES
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Líder : ANTONIO CARLOS GUIMARAES DE ALMEIDA
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MIEMBROS DE LA BANCA :
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ANTONIO CARLOS GUIMARAES DE ALMEIDA
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ANTONIO MARCIO RODRIGUES
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CARLA ALESSANDRA SCORZA BAHI
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FULVIO ALEXANDRE SCORZA
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LUIZ EDUARDO CANTON SANTOS
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RICARDO MARIO ARIDA
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Data: 24-ago-2020
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Resumen Espectáculo
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Chloride is the most abundant physiological anion and it determines elementary biological functions. Its intracellular levels result from a balance established by channels, exchangers and transporters present in the plasma membrane. Changes in the balance of this ion occur in pathological conditions such as epilepsy, in which the accumulation of intracellular chloride in neurons of the central nervous system (CNS) is related to the induction and sustentation of epileptiform activities. Dysfunctions in cation-chloride cotransporters (CCC’s) have been identified as the main responsible for this accumulation. Previous experiments have shown that perfusion with low extracellular chloride ([Cl-]o) (7 mM) reversibly blocks spontaneous hyper-synchronous discharges induced by high potassium [K+]o without reducing synaptic hyperexcitability. Furthermore, this anticonvulsant effect is similar to that of furosemide and, therefore, mediated by the effect on CCC`s, especially NKCC1 and KCC2. Thus, the aim of the present study was to investigate the extracellular depletion of the chloride ion as well as the influence of its regulatory mechanisms on non-synaptic epileptiform activities (AENS) induced in hippocampal slices of Wistar rats using the zero calcium and high [K+]o model (8 mM). Extracellular electrophysiological recordings in the dentate gyrus allowed us to evaluate the effect of these mechanisms on the AENS. In addition to sodium gluconate for equimolar replacement of the chloride ion, the use of furosemide (5 mM), bumetanide (12.5 μM), VU 0463271 (10 μM), acetazolamide (100 μM) and amiloride (0.5 mM), alone or combined, composed eighteen experimental groups. Programs developed on the MATLAB platform made it possible to record the extracellular electrical potential, and the parameters event duration (ED), interval between events (IE), amplitude of population spikes, (PS's), maximum amplitude (max. Amp) and DC component were quantified. The low extracellular [Cl-] maneuver did not cause suppression of the AENS, an effect obtained during the maneuver with furosemide. Conversely, the reduction in CCC activity caused by the low [Cl-] maneuver promoted greater neuronal excitability. Likewise, the selective blocking of NKCC1 with bumetanide, KCC2 with VU 0463271 or the simultaneous addition of both inhibitors (bumetanide + VU) did not suppress AENS, demonstrating an additional effect of furosemide on AENS, apart from the effect on cation-chloride cotransporters. Based on data from the literature, according to which the diuretic also acts on carbonic anhydrase and the sodium-independent chloride-bicarbonate exchanger (AE3), the next experimental step was to investigate the effect of the diuretic on pH, mechanisms that are also influenced by intracellular chloride concentrations. For this, the change in the pH of the extracellular medium was analyzed, maintaining the blocking of the cotransport mechanisms, with the use of furosemide and low [Cl-]o. By making the pH of the zero-calcium high-potassium solution more basic, around 7.55, the return of epileptiform activities was observed, showing that the blockage exerted by furosemide causes acidification of the extracellular medium. After elucidating the activity of furosemide on pH, the investigation of the effect of blocking mechanisms that act on neuronal pH in AENS was initiated, in order to identify the possible target(s) of this diuretic and, consequently, the mechanisms that make it possible to sustain epileptiform activities. However, the use of acetazolamide (ACZM), a carbonic anhydrase inhibitor, or other combined CCC inhibition maneuvers and neuronal pH regulatory mechanisms, such as bumetanide + VU + ACZM and zero [Cl-]o + ACZM did not promote the suppression of epileptiform activities. The
condition of zero [Cl-]o and zero [NaHCO3]o, however, which mimics AE3 block, unlike the other groups, showed a progressive reduction in epileptiform events, with a tendency towards suppression. Thus, the additional effect of a pH-regulating mechanism that has not yet been investigated, the Na+/H+ exchanger (NHE), was also evaluated, since during the ictal period, with the accumulation of intracellular sodium, an inversion of its performance is suggested, with the intrusion of a H+ ion and extrusion of a Na+ ion. The combination of the maneuvers resulted in the appearance of regular oscillations at the baseline with subsequent suppression of the AENS. In short, it was possible to observe that the suppression of AENS was only possible due to a combined action on different non-synaptic mechanisms, in this case, cation-chloride cotransporters and NHE exchanger, which would also influence the Na+/K+ ATPase activity. Still, the sodium/bicarbonate cotransporter (NBC) is a possible target of the diuretic, since it maintains the alkalinity of the extracellular medium, and, consequently, neuronal hyperexcitability. However, there is no specific blocker for this transport mechanism yet.
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9
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DELMO BENEDITO SILVA
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EFFECTS OF THE [Mg2+] REDUCTION DURINGINDUCTION OF NON-SYNAPTIC EPILLETIFORM ACTIVITIES
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Líder : ANTONIO MARCIO RODRIGUES
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MIEMBROS DE LA BANCA :
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ANTONIO CARLOS GUIMARAES DE ALMEIDA
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ANTONIO MARCIO RODRIGUES
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ANTONIO MAURICIO FERREIRA LEITE MIRANDA DE SA
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DIEGO BASILE COLUGNATI
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GISELE SILVA NOGUEIRA
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Data: 29-dic-2020
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Resumen Espectáculo
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Magnesium (Mg2+) is an essential mineral withcrucial role in several cellular functions and corresponds to the second most abundant intracellular cation. During the induction of epileptiform activities,reductionsin extracellular concentrations of Mg2+([Mg2+]) and calcium wereobserved. Most studies have focused on the effect of Mg2+on synaptic epileptiform activities;however,data on the effect of [Mg2+] reduction on non-synaptic epileptiform activities (NSEA) are scarce. Thegoal of the present work was, using experimental maneuvers and computational simulations, to understand the possible effects of [Mg2+] variation on NSEA. As an experimental protocol, NSEA were induced in rat hippocampal dentate gyrus (DG) hippocampus, using a bath solution containing high-K+and zero-added-Ca2+. Computer simulations were performed using a mathematical model that represents electrochemical characteristics of the tissue of the DG granular layer. The experimental results show that the reduction of [Mg2+] causes an increase in the duration of the ictal period anda reduction in the inter-ictal period, intensifying epileptiform discharges. The computer simulations suggest that the reduction of the Mg2+level intensifies the epileptiform discharges by a joint effect of reducing the surface charge screening and reducing the activity of the Na+/K+-ATPase.
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