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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Morphofunctional alterations in the olivocochlear efferent system of the genetic audiogenic seizure-prone hamster GASH:Sal

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Autor(es):
Sanchez-Benito, David ; Gomez-Nieto, Ricardo ; Hernandez-Noriega, Sonia ; Batista Murashima, Adriana Andrade ; Cortes de Oliveira, Jose Antonio ; Garcia-Cairasco, Norberto ; Lopez, Dolores E. ; Hyppolito, Miguel Angelo
Número total de Autores: 8
Tipo de documento: Artigo Científico
Fonte: Epilepsy & Behavior; v. 71, n. B, p. 193-206, JUN 2017.
Citações Web of Science: 3
Resumo

The genetic audiogenic seizure hamster (GASH:Sal) is a model of a form of reflex epilepsy that is manifested as generalized tonic-clonic seizures induced by external acoustic stimulation. The morphofunctional alterations in the auditory system of the GASH:Sal that may contribute to seizure susceptibility have not been thoroughly determined. In this study, we analyzed the olivocochlear efferent system of the GASH:Sal from the organ of Corti, including outer and inner hair cells, to the olivocochlear neurons, including shell, lateral, and medial olivocochlear (LOC and MOC) neurons that innervate the cochlear receptor. To achieve this, we carried out a multi-technical approach that combined auditory hearing screenings, scanning electron microscopy, morphometric analysis of labeled LOC and MOC neurons after unilateral Fluoro-Gold injections into the cochlea, and 3D reconstruction of the lateral superior olive (LSO). Our results showed that the GASH:Sal exhibited higher auditory brain response (ABR) thresholds than their controls, as well as absence of distortion-product of otoacoustic emissions (DPOAEs) in a wide range of frequencies. The ABR and DPOAE results also showed differences between the left and right ears, indicating asymmetrical hearing alterations in the GASH:Sal. These alterations in the peripheral auditory activity correlated with morphological alterations. At the cochlear level, the scanning electron microscopy analysis showed marked distortions of the stereocilia from basal to apical cochlear turns in the GASH:Sal, which were not observed in the control hamsters. At the brainstem level, MOC, LOC, and shell neurons had reduced soma areas compared with control animals. This LOC neuron shrinkage contributed to reduction in the ISO volume of the GASH:Sal as shown in the 3D reconstruction analysis. Our study demonstrated that the morphofunctional alterations of the olivocochlear efferent system are innate components of the GASH:Sal, which might contribute to their susceptibility to audiogenic seizures. (C) 2016 Elsevier Inc. All rights reserved. (AU)

Processo FAPESP: 07/50261-4 - Neurociências, epilepsia e arte: caracterização interdisciplinar da cepa WAR e modelos de epilepsia correlacionados: as oficinas Da Vinci, divulgação científica e quebras de estigmas em epilepsia
Beneficiário:Norberto Garcia Cairasco
Linha de fomento: Auxílio à Pesquisa - Temático
Processo FAPESP: 05/56447-7 - Pesquisa através de imagens por ressonância magnética de alto campo destinadas a estudos em humanos
Beneficiário:João Pereira Leite
Linha de fomento: Auxílio à Pesquisa - Programa CINAPCE - Temático