Alterações plásticas da epileptogênese com ênfase na reorganização colinérgica

• Autor(a) principal: Pereira, Heloisa Aparecida Alves [UNIFESP]
• Data de Publicação: 2006
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UNIFESP
• Texto Completo: http://repositorio.unifesp.br/handle/11600/8889
• topic: Epilepsia; Pilocarpina; Escopolamina; Acetilcolina; Hidrobrometo de escopolamina; Scopolamine hydrobromide; Acetylcholine; Pilocarpine; Epilepsy

Purpose: We investigated whether the administration of scopolamine, has the ability to interfere in the epileptogenic process and whether this effect could be explained by plastic changes in the cholinergic system. Methods: Two hours after pilocarpine-induced status epilepticus (SE, 320-350 mg/kg, i.p.), male Wistar rats received scopolamine (Pilo+Scopolamine group) 1-2 mg/kg i.p. or saline (Pilo group), every 6 hours for 3 days. After that, osmotic mimipumps were implanted for continuos delivery of scopolamine or saline for an additional 14 days. Animals were videomonitored for 12h/week during the following 3-months period for the occurrence of spontaneous recurrent seizures (SRS) and, thereafter, were perfused, processed and stained for acetylcholnesterase (AChE), neo-Timm and Nissl. Results: Administration of scopolamine decreased the number of SRS and increased latency for seizure onset. There was a decrease in the density of cholinergic positive fibers for AChE in all analised strutures of the Pilo+Scopolamine group as compared with Control and Pilo groups. Treatment with scopolamine however did not interfere with mossy fiber sprouting (MFS). Regression analysis did not indicate an association between SRS frequency and MFS or density of cholinergic fibers. Conclusions: The administration of scopolamine shortly after the inicial precipitant event and for a small period of time, lead to anatomical and functional consequences. Scopolamine interfered with epileptogenesis. However, the structural changes encountered with AChE histochemistry did not explain the epileptogenic and antiepileptogenic processes.