Role of the superior colliculus in the expression of acute and kindled audiogenic seizures in Wistar audiogenic rats

Autor(es)

Doretto, Maria C. ^[1] ; Cortes-de-Oliveira, Jose A. ; Rossetti, Franco ^[2] ; Garcia-Cairasco, Norberto ^{[3, 2]}

Afiliação do(s) autor(es)

^[1] Univ Fed Minas Gerais, Dept Physiol & Biophys, Belo Horizonte, MG - Brazil

^[2] Univ Sao Paulo, Neurol Psychiat & Med Psychol Dept, Ribeirao Preto Sch Med, BR-14049900 Sao Paulo - Brazil

^[3] Univ Sao Paulo, Dept Physiol, Ribeirao Preto Sch Med, Neurophysiol & Expt Neuroethol Lab, BR-14049900 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Epilepsia; v. 50, n. 12, p. 2563-2574, DEC 2009.
• Citações Web of Science: 11

Resumo

P>Purpose: The role of the superior colliculus (SC) in seizure expression is controversial and appears to be dependent upon the epilepsy model. This study shows the effect of disconnection between SC deep layers and adjacent tissues in the expression of acute and kindling seizures. Methods: Subcollicular transections, ablation of SC superficial and deep layers, and ablation of only the cerebral cortex were evaluated in the Wistar audiogenic rat (WAR) strain during acute and kindled audiogenic seizures. The audiogenic seizure kindling protocol started 4 days after surgeries, with two acoustic stimuli per day for 10 days. Acute audiogenic seizures were evaluated by a categorized seizure severity midbrain index (cSI) and kindled seizures by a severity limbic index (LI). Results: All subcollicular transections reaching the deep layers of the SC abolished audiogenic seizures or significantly decreased cSI. In the unlesioned kindled group, a reciprocal relationship between limbic and brainstem pattern of seizures was seen. The increased number of stimuli provoked an audiogenic kindling phenomenon. Ablation of the entire SC (ablation group) or of the cerebral cortex only (ctx-operated group) hampered the acquisition of limbic behaviors. There was no difference in cSI and LI between the ctx-operated and ablation groups, but there was a difference between ctx-operated and the unlesioned kindled group. There was also no difference in cSI between SC deep layer transection and ablation groups. Results of histologic analyses were similar for acute and kindled audiogenic seizure groups. Conclusions: SC deep layers are involved in the expression of acute and kindled audiogenic seizure, and the cerebral cortex is essential for audiogenic kindling development. (AU)

• Processo FAPESP: 05/56447-7 - Pesquisa através de imagens por ressonância magnética de alto campo destinadas a estudos em humanos
• Beneficiário: João Pereira Leite
• Modalidade de apoio: Auxílio à Pesquisa - Programa CINAPCE - Temático
• Processo FAPESP: 03/12420-2 - Caracterização de receptores GABAA na substância negra e sua relação com as crises audiogênicas em ratos da cepa Wistar Audiogenic Rat (WAR)
• Beneficiário: Franco Rossetti
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 03/00873-2 - Caracterização neuroetológica, video-EEgráfica e anatômica dos efeitos comportamentais e neurotóxicos da ingestão do suco de carambola (Averrhoa carambola) em ratos com insuficiência renal aguda
• Beneficiário: Norberto Garcia Cairasco
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 03/11381-3 - Caracterização de sistemas anticonvulsivantes endógenos: avaliação neuroetológica, eletroencefalográfica e celular nos modelos experimentais de epilepsia, bicuculina intrahipocampal e crises audiogênicas nos ratos da cepa WAR
• Beneficiário: Marcelo Cairrão Araujo Rodrigues
• Modalidade de apoio: Auxílio à Pesquisa - Programa Primeiros Projetos
• Processo FAPESP: 03/01134-9 - Caracterização de sistemas anticonvulsivantes endógenos: avaliação neuroetológica, eletroencefalográfica e celular nos modelos experimentais de epilepsia, bicuculina intrahipocampal e crises audiogênicas nos ratos da cepa WAR
• Beneficiário: Marcelo Cairrão Araujo Rodrigues
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado