Avaliação da expressão gênica do sistema ocitocinérgico em ratos expostos ao status epilepticus neonatal

• Autor(a) principal: Pacifico, Ana Miriã
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações do Mackenzie
• Texto Completo: http://dspace.mackenzie.br/handle/10899/22690
• topic: status epilepticus neonatal; ocitocina; memória social; modelo animal; CNPQ::OUTROS

Experimental studies show evidence that rats subjected to neonatal seizures have morphological and cognitive changes, also exhibiting autistic behavior characterized by low preference for social novelty, social discrimination deficits and behavior type anxious. However, the mechanisms that account for these changes are not yet known. Several lines of evidence show that Oxytocin (OT) is present in key regions for social recognition, such as the medial amygdala and the hippocampus. We postulate that the deficiency in signaling mediated by OT on neural network related to the social brain responds by impaired sociability and increased emotionality subsequent neonatal seizure. This study aims to assess the social recognition memory and gene expression of OT and its receptor (OTR) in animals with neonatal status epilepticus. Wistar rats were adult males submitted to status epilepticus on the ninth day of life (P9) the administration of pilocarpine (350 mg / kg, ip) and the controls received saline 0.9% (0.1 ml / 10 g). In P90 social memory was evaluated by habituation/deshabituation paradigm. At the end of behavioral testing, the animals were anesthetized and decapitated to remove the structures of study (amygdala, hippocampus, and hypothalamus). Thereafter it was performed gene expression analysis of oxytocin and its receptor in the aforementioned tissues by real-time PCR. In social memory test experimental animals had shorter social research, injury indicative of the motivation system / reward and loss of habituation / deshabituation, suggesting impairment in social recognition memory. The gene expression of oxytocin did not differ between the groups in the analyzed structures, but there was a small decrease in gene expression of oxytocin receptor in the hippocampus. Thus concludes the neonatal status epilepticus in rats produces memory deficits in social recognition and motivation /mesolímibic reward systems. This work demonstrated that animals subjected to neonatal status epilepticus have reduced exploration of social novelty, suggesting impairment in motivation system / mesolimbic reward and social recognition memory that may be related to reduced expression of oxytocin receptors in the hippocampus.