Reorganization of the septohippocampal cholinergic fiber system in experimental epilepsy

• Tipo: Artigo em Revista Científica Internacional
• Data: 2017

Autores

Soares, JI (Autor) Outra; Valente, MC (Autor) Outra; Andrade, PA (Autor) Outra; Maia, GH (Autor) Outra; Lukoyanov, NV (Autor) FMUP

Revista

Título: Journal of Comparative Neurology

Vol. 525

Páginas: 2690-2705

ISSN: 0021-9967

Editora: Wiley-Blackwell

Indexação

ISI Web of Knowledge - 14 Citações

Scopus - 13 Citações

Outras Informações

ID Authenticus: P-00N-5BM

DOI: 10.1002/cne.24235

Abstract (EN): The septohippocampal cholinergic neurotransmission has long been implicated in seizures, but little is known about the structural features of this projection system in epileptic brain. We evaluated the effects of experimental epilepsy on the areal density of cholinergic terminals (fiber varicosities) in the dentate gyrus. For this purpose, we used two distinct post-status epilepticus rat models, in which epilepsy was induced with injections of either kainic acid or pilocarpine. To visualize the cholinergic fibers, we used brain sections immunostained for the vesicular acetylcholine transporter. It was found that the density of cholinergic fiber varicosities was higher in epileptic rats versus control rats in the inner and outer zones of the dentate molecular layer, but it was reduced in the dentate hilus. We further evaluated the effects of kainate treatment on the total number, density, and soma volume of septal cholinergic cells, which were visualized in brain sections stained for either vesicular acetylcholine transporter or choline acetyltransferase (ChAT). Both the number of septal cells with cholinergic phenotype and their density were increased in epileptic rats when compared to control rats. The septal cells stained for vesicular acetylcholine transporter, but not for ChAT, have enlarged perikarya in epileptic rats. These results revealed previously unknown details of structural reorganization of the septohippocampal cholinergic system in experimental epilepsy, involving fiber sprouting into the dentate molecular layer and a parallel fiber retraction from the dentate hilus. We hypothesize that epilepsy-related neuroplasticity of septohippocampal cholinergic neurons is capable of increasing neuronal excitability of the dentate gyrus.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 16