Efeitos da aplicação de neurotensina na amígdala centromedial sobre a memória de reconhecimento social de ratos

• Autor(a) principal: Pereira, Fabio Pacheco Marques [UNIFESP]
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UNIFESP
• dARK ID: ark:/48912/001300000qcfj
• Texto Completo: https://sucupira.capes.gov.br/sucupira/public/consultas/coleta/trabalhoConclusao/viewTrabalhoConclusao.jsf?popup=true&id_trabalho=4258337; http://repositorio.unifesp.br/handle/11600/47374
• topic: Neurotensin receptor; Short-term memory; Social behavior; Social discrimination; Amygdala; Rats; Receptores de neurotensina; Memória de curto prazo; Comportamento social; Discriminação social; Amígdala; Ratos

The neurotensin (NT), a neurotransmitter and neuromodulator widely distributed in the central nervous system has been a major subject of research in recent decades in areas such as schizophrenia, autism, and the mechanism and control of pain. In all mammalian species the recognition of different individuals is critical in differentiating what is familiar or unfamiliar in the elicitation of behavioral and emotional responses appropriate to each situation as for learning these situations from the first social contact. The objective of the study was to observe whether the exogenous administration of neurotensin in the centromedial amygdala of rats may interfere in the regulation of social recognition for short and long term memory. In this context, ten groups of rats were injected bilaterally with saline or one of three doses of NT (0.1, 0.23 or 1 ?g) or one of two doses of SR48692 (0.035 or 0.233 ?g) on the centromedial amygdala. The social discrimination protocol was used, using a interval of 30, 90 minutes or 24 hours between the learning and testing phase. The substances were injected after the learning phase, and it was observed if the administration of these doses can interfere with the regulatory mechanisms of social memory. After 30 minutes only animals injected with the dose of 1 ?g of NT failed to differentiate the familiar subject from the novel subject during the test. Within 90 minutes, the rats injected with the dose of 0.23 ?g of NT were able to differentiate the juvenile rat, while the control in this interval could not distinguish between animals. The administration of SR48692, a selective receptor 1 NT antagonist in a 30 minute interval could prevent the animals discriminating the familiar from the novel animal, while control animals could distinguish it. The results of this study suggest that the presence of neurotensin in the centromedial amygdala can assist in regulating the social recognition system of rats. Moreover, both agonism as the antagonism of the NTS1 receptor may indicate that this receptor is an important facilitator of the action of neurotransmitters and neuromodulators on the social recognition memory.