Neocortical and hippocampal changes after multiple pilocarpine-induced status epilepticus in rats

• Autor(a) principal: Silva, A. V. da
• Data de Publicação: 2005
• Outros Autores: Regondi, M. C., Cipelletti, B., Frassoni, C., Cavalheiro, Esper Abrão [UNIFESP], Spreafico, R.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNIFESP
• Texto Completo: http://repositorio.unifesp.br/11600/43553; https://dx.doi.org/10.1111/j.1528-1167.2005.31604.x
• topic: immature brain; early insult; immunocytochemistry; immunohistoblot

Purpose: Multiple episodes of pilocarpine-induced status epilepticus (SE) in developing rats (P7-P9) lead to progressive epileptiform activity and severe cognitive impairment in adulthood. The present work studied possible underlying abnormalities in the neocortex and hippocampus of pilocarpine-treated animals.Methods: Wistar rats were submitted to pilocarpine-induced SE at P7, P8, and P9, and were killed at P35. Immunocytochemistry was performed on 50-mu m vibratome sections, by using antibodies against nonphosphorylated neurofilament (SMI-311), parvalbumin (PV), calbindin (CB), calretinin (CR), and glutamate decarboxylase (GAD-65). Ten-micron cryostat sections were processed for immunohistoblot by using antibodies against GluR1, GluR2/3, and GluR4 alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunits and NR2ab N-methyl-D-aspartate (NMDA) receptor subunit.Results: Adult rats submitted to SE at P7-9 showed: (a) altered distribution of neocortical interneurons; (b) increased cortical and reduced hippocampal GAD-65 expression; and (c) altered expression of hippocampal AMPA and NMDA receptors.Conclusions: We conclude that multiple SE episodes during P7-9 generate long-lasting disturbances that underlie behavioral and electrographic abnormalities later in life.