Navegando por Palavras-chave "Maximal electroshock"

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    Maximal electroshock-induced seizures are able to induce Homer1a mRNA expression but not pentylenetetrazole-induced seizures
    (Elsevier B.V., 2015-03-01) Cavarsan, Clarissa F. [UNIFESP]; Matsuo, Alisson [UNIFESP]; Blanco, Miriam M. [UNIFESP]; Mello, Luiz E. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Objective: Homer1a is a protein that regulates metabotropic glutamate receptors involved in neural plasticity processes. Recently, we demonstrated that Homer1a mRNA is enhanced after pilocarpine-induced status epilepticus. Here, we investigated whether a single acute seizure triggered by means of pentylenetetrazole (PTZ) injection or maximal electroshock (MES) stimulation (2 different seizure models) would alter Homer1a expression in the hippocampus.Methods: Male Wistar rats subjected to the PTZ or MES model were analyzed 2 h, 8 h, 24 h, and 7 days after seizure induction. Homer1a, mGluR1, and mGluR5 mRNA expression levels in hippocampal extracts were analyzed by quantitative PCR.Results: Quantitative PCR revealed Homer1a overexpression at 2 h after MES-induced tonic-clonic seizures compared to control, but the overexpression did not remain elevated after 8 h. Pentylenetetrazole-induced seizures, in contrast, were not able to change Homer1a mRNA expression. No differences were observed at these time points after seizures for mGluR1 and mGluR5 mRNA expression in any of the models.Significance: Our data indicate that the levels of Homer1a mRNA were transiently increased only after MES induced tonic-clonic seizures (and not after PTZ-induced seizures). We suggest that Homer1a expression may be dependent on seizure intensity or on specific brain circuit activation. We suggest that Homer1a may contribute to counteract hyperexcitability processes. (C) 2015 Elsevier Inc. All rights reserved.
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    Transplantation of inhibitory precursor cells from medial ganglionic eminence produces distinct responses in two different models of acute seizure induction
    (Academic Press Inc Elsevier Science, 2017) Paiva, Daisylea de Souza [UNIFESP]; Alves Romariz, Simone Amaro [UNIFESP]; Valente, Maria Fernanda [UNIFESP]; Moraes, Luiz Bruno [UNIFESP]; Covolan, Luciene [UNIFESP]; Calcagnotto, Maria Elisa; Longo, Beatriz Monteiro [UNIFESP]
    Medial ganglionic eminence (MGE) is one of the sources of inhibitory interneurons during development. Following transplantation in postnatal developing brain, MGE cells can increase local inhibition suggesting a possible protection to GABAergic dysfunction in brain disorders, such as epilepsy. Since it has been shown that MGE-derived cells harvested as neurospheres are able to suppress seizures, it might be important to investigate whether these protective effects would change in different seizure models. Here, we used pentylenetetrazole(PTZ) and maximal electroshock (MES)-induced seizure models to test whether the transplantation of MGE cells would increase the threshold to trigger acute seizures. When transplanted into the neocortex (layers 3-4) of neonatal mice (postnatal days 3-4), MGE cells were able to survive and were mainly found in piriform cortex, fimbria, and ventricular wall regions. Additionally, the number of GFP + cells found in the brains of mice induced with PTZ and MES differed significantly and suggests proliferation and larger survival rate of MGE-transplanted cells after PTZ, but not MES-induced seizures. Following transplantation, there was a reduction in the number of animals presenting mild and severe seizures induced by PTZ. Furthermore, MGE-cell transplantation was able to increase threshold to seizures induced by PTZ, but was not able to prevent seizure spread induced by MES. (C) 2017 Elsevier Inc. All rights reserved.