Navegando por Palavras-chave "Status epilepticus"
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- ItemAcesso aberto (Open Access)Absence-like seizures in adult rats following pilocarpine-induced status epilepticus early in life(Associação Brasileira de Divulgação Científica, 2003-12-01) Ferreira, B.l.c. [UNIFESP]; Valle, A.c.; Cavalheiro, Esper Abrão [UNIFESP]; Timo-iaria, C.; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)Administration of pilocarpine causes epilepsy in rats if status epilepticus (SE) is induced at an early age. To determine in detail the electrophysiological patterns of the epileptogenic activity in these animals, 46 Wistar rats, 7-17 days old, were subjected to SE induced by pilocarpine and electro-oscillograms from the cortex, hippocampus, amygdala, thalamus and hypothalamus, as well as head, rostrum and vibrissa, eye, ear and forelimb movements, were recorded 120 days later. Six control animals of the same age range did not show any signs of epilepsy. In all the rats subjected to SE, iterative spike-wave complexes (8.1 ± 0.5 Hz in frequency, 18.9 ± 9.1 s in duration) were recorded from the frontal cortex during absence fits. However, similar spike-wave discharges were always found also in the hippocampus and, less frequently, in the amygdala and in thalamic nuclei. Repetitive or single spikes were also detected in these same central structures. Clonic movements and single jerks were recorded from all the rats, either concomitantly with or independently of the spike-wave complexes and spikes. We conclude that rats made epileptic with pilocarpine develop absence seizures also occurring during paradoxical sleep, showing the characteristic spike-wave bursts in neocortical areas and also in the hippocampus. This is in contrast to the well-accepted statement that one of the main characteristics of absence-like fits in the rat is that spike-wave discharges are never recorded from the hippocampal fields.
- ItemAcesso aberto (Open Access)Assessment of the progressive nature of cell damage in the pilocarpine model of epilepsy(Associação Brasileira de Divulgação Científica, 2006-07-01) Covolan, Luciene [UNIFESP]; Mello, Luiz Eugenio Araujo de Moraes [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Pilocarpine-induced (320 mg/kg, ip) status epilepticus (SE) in adult (2-3 months) male Wistar rats results in extensive neuronal damage in limbic structures. Here we investigated whether the induction of a second SE (N = 6) would generate damage and cell loss similar to that seen after a first SE (N = 9). Counts of silver-stained (indicative of cell damage) cells, using the Gallyas argyrophil III method, revealed a markedly lower neuronal injury in animals submitted to re-induction of SE compared to rats exposed to a single episode of pilocarpine-induced SE. This effect could be explained as follows: 1) the first SE removes the vulnerable cells, leaving behind resistant cells that are not affected by the second SE; 2) the first SE confers increased resistance to the remaining cells, analogous to the process of ischemic tolerance. Counting of Nissl-stained cells was performed to differentiate between these alternative mechanisms. Our data indicate that different neuronal populations react differently to SE induction. For some brain areas most, if not all, of the vulnerable cells are lost after an initial insult leaving only relatively resistant cells and little space for further damage or cell loss. For some other brain areas, in contrast, our data support the hypothesis that surviving cells might be modified by the initial insult which would confer a sort of excitotoxic tolerance. As a consequence of both mechanisms, subsequent insults after an initial insult result in very little damage regardless of their intensity.
- ItemSomente MetadadadosConsequences of pilocarpine-induced status epilepticus in immunodeficient mice(Elsevier B.V., 2012-04-23) Vignoli, Thiago [UNIFESP]; Nehlig, Astrid; Massironi, Silvia Gomes; Sinigaglia Coimbra, Rita de Cassia [UNIFESP]; Naffah Mazzacoratti, Maria da Graca [UNIFESP]; Silva, Iara Ribeiro [UNIFESP]; Castro Neto, Eduardo Ferreira de [UNIFESP]; Persike, Daniele Suzete [UNIFESP]; Silva Fernandes, Maria Jose da [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Univ Strasbourg; Universidade de São Paulo (USP)Systemic injection of pilocarpine in rodents induces status epilepticus (SE) and reproduces the main characteristics of temporal lobe epilepsy (TLE). Different mechanisms are activated by SE contributing to cell death and immune system activation. We used BALB/c nude mice, a mutant that is severely immunocompromised, to characterize seizure pattern, neurochemical changes, cell death and c-Fos activation secondarily to pilocarpine-induced SE. the behavioral seizures were less severe in BALB/c nude than in BALB/c wild type mice. However, nude mice presented more tonic clonic episodes and higher mortality rate during SE. the c-Fos expression was most prominent in the caudate-putamen, CA3 (p < 0.05), dentate gyrus, entorhinal cortex (p < 0.001), basolateral nucleus of amygdala (p < 0.01) and piriform cortex (p < 0.05) of BALB/c nude mice than of BALB/c. Besides, nude mice subjected to SE presented high number of Fluorojade-B (FJB) stained cells in the piriform cortex, amygdala (p < 0.05) and hilus (p < 0.05) in comparison with BALB/c mice. A significant increase in the level of glutamate and GABA was found in the hippocampus and cortex of BALB/c mice presenting SE in comparison to controls. However, the level of glutamate was higher in the brains of BALB nude mice than in the brains of BALB/c wild type mice, while the levels of GABA were unchanged. These results indicate that the brains of immunodeficient nude mice are more vulnerable to the deleterious effects of pilocarpine-induced SE as they present intense activation, increased glutamate levels and more cell death. Published by Elsevier B.V.
- ItemAcesso aberto (Open Access)Differential neuroprotection by A(1) receptor activation and A(2A) receptor inhibition following pilocarpine-induced status epilepticus(Elsevier B.V., 2011-10-01) Rosim, Fernanda Elisa [UNIFESP]; Persike, Daniele Suzete [UNIFESP]; Nehlig, Astrid; Amorim, Rebeca Padrão [UNIFESP]; Oliveira, Daniela Mara de; Fernandes, Maria Jose da Silva [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); INSERM; Universidade de Brasília (UnB)Aiming at a better understanding of the role of A(2A) in temporal lobe epilepsy (TLE), we characterized the effects of the A(2A) antagonist SCH58261 (7-(2-phenylethyl)-5-amino-2(2-furyl)-pyrazolo-[4,3-e]-1,2,4-triazolo[1,5-c] pyrimidine) on seizures and neuroprotection in the pilocarpine model. the effects of SCH58261 were further analyzed in combination with the A(1) agonist R-Pia (R(-)-N-6-(2)-phenylisopropyl adenosine). Eight groups were studied: pilocarpine (Pilo), SCH + Pilo, R-Pia + Pilo, R-Pia + SCH + Pilo, Saline, SCH + Saline, R-Pia + Saline, and R-Pia + SCH + Saline. the administration of SCH58261, R-Pia, and R-Pia + SCH58261 prior to pilocarpine increased the latency to SE, and decreased either the incidence of or rate of mortality from SE compared with controls. Administration of R-Pia and R-Pia + SCH58261 prior to pilocarpine reduced the number of Fluoro-Jade B-stained cells in the hippocampus and piriform cortex when compared with control. This study showed that pretreatment with R-Pia and SCH58261 reduces seizure occurrence, although only R-Pia has neuroprotective properties. Further studies are needed to clarify the neuroprotective role of A(2A) in TLE. (C) 2011 Elsevier Inc. All rights reserved.
- ItemSomente MetadadadosDistribution and proliferation of bone marrow cells in the brain after pilocarpine-induced status epilepticus in mice(Wiley-Blackwell, 2010-08-01) Longo, Beatriz [UNIFESP]; Romariz, Simone [UNIFESP]; Blanco, Miriam Marcela [UNIFESP]; Vasconcelos, Juliana Fraga; Bahia, Luciana; Pereira Soares, Milena Botelho; Mello, Luiz E. [UNIFESP]; Ribeiro-dos-Santos, Ricardo; Universidade Federal de São Paulo (UNIFESP); Hosp Sao RafaelP>The distribution of bone marrow cells in brain areas during the acute period after pilocarpine-induced status epilepticus (SE) was investigated here. To achieve this, we generated chimeric mice by engrafting bone marrow cells from enhanced green fluorescent protein (eGFP) transgenic mice. GFP+ bone marrow-derived cells were found throughout the brain, predominantly in the hippocampus. As expected, these cells exhibited the characteristics of microglia. the pattern of distribution, proliferation, and differentiation of GFP+ cells changes as a function of intensity and time following SE. This pattern is also a consequence of the inflammatory response, which is followed by the progressive neuronal damage that is characteristic of the pilocarpine model.
- ItemSomente MetadadadosMelatonin administration after pilocarpine-induced status epilepticus: A new way to prevent or attenuate postlesion epilepsy?(Elsevier B.V., 2011-04-01) Lima, Eliangela; Cabral, Francisco R.; Cavalheiro, Esper A.; Naffah-Mazzacoratti, Maria da Graca [UNIFESP]; Amado, Debora [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Hosp Israelita Albert EinsteinObjective: the goal of this study was to verify the effects of treatment with melatonin and N-acetylserotonin on the pilocarpine-induced epilepsy model.Methods: the animals were divided into four groups: (1) animals treated with saline (Saline); (2) animals that received pilocarpine and exhibited SE (SE); (3) animals that exhibited SE and were treated with N-acetylserotonin (30 minutes and 1, 2, 4, 6, 12, 24, 36, and 48 hours) alter SE onset (SE + NAS); (4) animals that exhibited SE and were treated with melatonin at the same time the SE + NAS group (SE + MEL). Behavioral (latency to first seizure, frequency of seizures, and mortality) and histological (Nissl and neo-Timm) parameters were analyzed.Results: the animals treated with melatonin (SE + MEL) had a decreased number of spontaneous seizures during the chronic period (P<0.05), a reduction in mossy fiber sprouting, and less cell damage than the SE group. Animals treated with N-acetylserotonin did not exhibit any kind of significant change.Conclusion: Melatonin exerts an important neuroprotective effect by attenuating SE-induced postlesion and promoting a decrease in the number of seizures in epileptic rats. This suggests, for the first time, that melatonin could be used co-therapeutically in treatment of patients exhibiting SE to minimize associated injuries in these situations. (C) 2011 Published by Elsevier Inc.
- ItemSomente MetadadadosModeling epileptogenesis and temporal lobe epilepsy in a non-human primate(Elsevier B.V., 2011-09-01) Perez-Mendes, P. [UNIFESP]; Blanco, M. M. [UNIFESP]; Calcagnotto, M. E. [UNIFESP]; Cinini, S. M. [UNIFESP]; Bachiega, J. [UNIFESP]; Papoti, D. [UNIFESP]; Covolan, Luciene [UNIFESP]; Tannus, A. [UNIFESP]; Mello, L. E. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Here we describe a new non-human primate model of temporal lobe epilepsy (TLE) to better investigate the cause/effect relationships of human TLE. Status epilepticus (SE) was induced in adult marmosets by pilocarpine injection (250 mg/kg; i.p.). the animals were divided in 2 groups: acute (8 h post-SE) and chronic (3 and 5 months post-SE). To manage the severity of SE, animals received diazepam 5 min after the SE onset (acute group: 2.5 or 1.25 mg/kg; i.p.; chronic group/; 1.25 mg/kg; i.p). All animals were monitored by video and electrocorticography to assess SE and subsequent spontaneous recurrent seizures (SRS). To evaluate brain injury produced by SE or SRS we used argyrophil III, Nissl and neo-Timm staining techniques. Magnetic resonance image was also performed in the chronic group. We observed that pilocarpine was able to induce SE followed by SRS after a variable period of time. Prolonged SE episodes were associated with brain damage, mostly confined to the hippocampus and limbic structures. Similar to human TLE, anatomical disruption of dentate gyrus was observed after SRS. Our data suggest that pilocarpine marmoset model of epilepsy has great resemblance to human TLE, and could provide new tools to further evaluate the subtle changes associated with human epilepsy. (C) 2011 Elsevier B.V. All rights reserved.
- ItemSomente MetadadadosThe sleep-wake cycle in adult rats following pilocarpine-induced temporal lobe epilepsy(Elsevier B.V., 2010-03-01) Matos, Gabriela; Tsai, Rodrigo; Baldo, Marcus Vinicius; Castro, Isac de [UNIFESP]; Sameshima, Koichi; Valle, Angela Cristina; Universidade de São Paulo (USP); Universidade Estadual de Campinas (UNICAMP); Universidade Federal de São Paulo (UNIFESP)The relationship between sleep and epilepsy is both complex and clinically significant. Temporal lobe epilepsy (TLE) influences sleep architecture, while sleep plays an important role in facilitating and/or inhibiting possible epileptic seizures. the pilocarpine experimental model reproduces several features of human temporal lobe epilepsy and is one of the most widely used models in basic research. the aim of the present study was to characterize, behaviorally and electrophysiologically, the phases of sleep-wake cycles (SWC) in male rats with pilocarpine-induced epilepsy. Epileptic rats presented spikes in all phases of the SWC as well as atypical cortical synchronization during attentive wakefulness and paradoxical sleep. the architecture of the sleep-wake phases was altered in epileptic rats, as was the integrity of the SWC. Because our findings reproduce many relevant features observed in patients with epilepsy, this model is suitable to study sleep dysfunction in epilepsy. (C) 2009 Elsevier Inc. All rights reserved.
- ItemSomente MetadadadosSocial play impairment following status epilepticus during early development(Springer, 2010-10-01) Santos Castelhano, Adelisandra Silva; Scorza, Fulvio Alexandre [UNIFESP]; Triguero Veloz Teixeira, Maria Cristina; Arida, Ricardo Mario [UNIFESP]; Cavalheiro, Esper Abrao [UNIFESP]; Cysneiros, Roberta Monterazzo; Univ Presbiteriana Mackenzie; Universidade Federal de São Paulo (UNIFESP)Neonatal status epilepticus (SE) disrupts prefrontal cortex and thalamus, brain regions related to social play. Juvenile play was evaluated using the intruder-resident paradigm following SE in 9-day-old Wistar pups of both genders. Quite interestingly, we demonstrated for the first time that neonatal SE produces social impairment in male rats, reduces locomotor activity in both genders and enhances self-grooming in female. Additional studies are necessary to clarify if these effects can impair social behavior across the life span.
- ItemSomente MetadadadosStatus epilepticus does not induce acute brain inflammatory response in the Amazon rodent Proechimys, an animal model resistant to epileptogenesis(Elsevier Ireland Ltd, 2018) Scorza, Carla Alessandra [UNIFESP]; Marques, Marcia Jonathas Guimaraes [UNIFESP]; Silva, Sergio Gomes da [UNIFESP]; Naffah-Mazzacoratti, Maria da Graca [UNIFESP]; Scorza, Fulvio Alexandre [UNIFESP]; Cavalheiro, Esper Abrão [UNIFESP]Mesial temporal lobe epilepsy is a serious brain disorder in adults that is often preceded by an initial brain insult, such as status epilepticus (SE), that after a latent period leads to recurrent seizures. Post SE models are widely used for studies on epileptogenic processes. Previous findings of our laboratory suggested that the Neotropical rodents Proechimys exhibit endogenous antiepileptogenic mechanisms in post-SE models. Strong body of research supports that SE triggers a rapid and dramatic upregulation of inflammatory mediators and vascular endothelial growth factor (VEGF). In this work we found that, in the epilepsy-resistant Proechimys, hippocampal and cortical levels of inflammatory cytokines (1L-1 beta, 1L-6, IL-10, TNF-alpha) and VEGF remained unchanged 24 h after SE, strongly contrasting to the high levels of post-SE changes observed in Wistar rats. Furthermore, substantial differences in the brain baseline levels of these proteins were encountered between animal species studied. Since inflammatory cytokines and VEGF have been recognized as major orchestrators of the epileptogenic process, our results suggest their role in the antiepileptogenic mechanisms previously described in Proechimys. (C) 2017 Elsevier B.V. All rights reserved.
- ItemSomente MetadadadosThe synthesis and distribution of the kinin B1 and B2 receptors are modified in the hippocampus of rats submitted to pilocarpine model of epilepsy(Elsevier B.V., 2004-04-23) Arganaraz, G. A.; Silva, J. A.; Perosa, SR; Pessoa, L. G.; Carvalho, F. F.; Bascands, J. L.; Bader, M.; Trindade, E. D.; Amado, D.; Cavalheiro, E. A.; Pesquero, J. B.; Naffah-Mazzacoratti, M. D.; Universidade Federal de São Paulo (UNIFESP); Universidade Federal do Rio de Janeiro (UFRJ); Fac Med Toulouse; Max Delbruck CtrKinins, a special class of polypeptides, are represented by bradykinin (BK), kallidin (Lys-BK), as well as their metabolites. the biological actions of these polypeptides binding on their receptors (B1 and B2) have been related to inflammation process, cytokines action, glutamate release and prostaglandins production. Usually, kinin B1 receptor is not expressed at a significant level under physiologic conditions in most tissues, but its expression is induced by injury, or upon exposure in vivo or in vitro to pro-inflammatory mediators. the kinin B2 receptor subtype is constitutively and widely expressed throughout the central and peripheral nervous system. These data raise the possibility for de novo expression of those receptors during the temporal lobe epilepsy (TLE), which has been related to cell death, gliosis and hippocampal reorganization. To correlate kinin system and TLE, adult male Wistar rats were submitted to pilocarpine model of epilepsy. the hippocampi were removed 6 h, 5 and 60 days after status epilepticus (SE) onset. the collected tissues were used to study the expression of kinin B1 and B2 mRNA receptors, using Real-Time PCR. Immunohistochemistry assay was also employed to visualize kinin B1 and B2 distribution in the hippocampus. the results show increased kinin B1 and B2 mRNA levels during acute, silent and chronic periods and changes in the kinin B1 and B2 receptors distribution. in addition, the immunoreactivity against kinin B1 receptor was increased mainly during the silent period, where neuron clusters of could be visualized. the kinin B2 receptor immunoreactivity also showed augmentation but mainly during the acute and silent periods. Our results suggest that kinin B1 and B2 receptors play an important role in the epileptic phenomena. (C) 2004 Elsevier B.V. All rights reserved.
- ItemAcesso aberto (Open Access)Videomonitoração de longa duração (1 ano) de fêmeas que não desenvolveram status epilepticus pós pilocarpina e a possível ocorrência de crises espontâneas tardias(Universidade Federal de São Paulo (UNIFESP), 2017-12-14) Dal Pai, Janise [UNIFESP]; Scerni, Debora Amado [UNIFESP]; http://lattes.cnpq.br/3964840204818021; http://lattes.cnpq.br/4876667602899673; Universidade Federal de São Paulo (UNIFESP)Introduction: Epilepsy is one of the main neurologic diseases and Temporal Lobe Epilepsy (TLE) is the most frequent form. TLE affects the minimum of 20% of all patient with epilepsy and equally around 50 million of man and woman in the whole world. The use of the experimental model of epilepsy by administering the cholinergic agonist Pilocarpine (Pilo) mimics most of the behavioral and electrographic alterations found in TLE. Female rats submitted to this model allow the study of the hypothalamic-pituitary-gonadal axis alterations due to epileptic seizures. Studies in our laboratory has shown that 47% of the whole female rats who has received Pilo did not develop status epilepticus (SE). Navarro et al. (2009) found that male rats that did not develop SE (NSE) after receiving Pilo showed up spontaneous and recurrent seizures (SRS) starting 6-8 months after treatment with the drug. The study of TLE in ovariectomized (OVX) and non ovariectomized female rats (NOVX) induced to Pilo model that did not develop SE may show up important informations about the mechanisms involved in the generation and in the absence of SE in female rats, also the physiopathology of Pilo experimental model and the hormonal neuroprotection in the physiopathology of epilepsy. Aims: To investigate whether NOVX and OVX female rats, before or after receiving Pilo, and did not have SE, will develop SRS in the following one-year videomonitoring period. Methods: OVX and NOVX female rats (with regular cycle) received 360 mg/kg of Pilo ip. and were distributed in 6 experimental groups NSE, NSEOVX, OVXNSE, SE, SEOVX and OVXSE. Female rats were videomonitored for 12 months for the observation of SRS. The video acquired along this period were analyzed in fast speed and after that in real speed (speed in which the movements occur) in search of motor alterations. Results: Female rats from SE, SEOVX and OVXSE groups had their recordings watched in the fast speed, which allowed the observation that all of them became epileptic. Some females have even showed seizure upper to stage 5 from Racine (1972) and were classified as class motor seizures by Pinel e Rovner (1978a e 1978b). No motor alterations could be verified in the NSE, NSEOVX and OVXNSE females when recordings were analyzed in the fast speed. However, when the real speed was used, it was possible to identify very similar behaviors described as stages 1-3 from Racine (1972) and were classified as suggested seizures. Besides these, other behaviors not yet described in the literature for animals injected with Pilo were observed, however some of them are very similar to motor alterations seen in epilepsy patients. These behaviors were also identified in SE, SEOVX and OVXSE female groups. Considering the findings of this thesis, it is suggested a complement to be added to the classifications already known for seizures in rats named FeBAP Classification, which may be used in female rats that developed or not SE after being induced to Pilo model. Conclusion: Watching the videomonitoring in the real speed was essential for identifying motor alterations in NSE, NSEOVX and OVXNSE female groups. The similarity among observed manifestations, those described as stages 1-3 and behaviors found in SE, SEOVX and OVXSE female groups suggest that those are seizures with origin in a possible epileptogenic focus. Videomonitoring was fundamental for identifying motor alterations however, there is a need of an electroencephalographic study to confirm the findings from this work.