Investigação do papel de receptores do tipo 5-HT3 do núcleo dorsal da rafe na modulação de comportamentos relacionados à ansiedade em ratas

• Ano de defesa: 2016
• Autor(a) principal: Freire, Bárbara Thaise da Silva
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Brasil; UFRN; PROGRAMA DE PÓS-GRADUAÇÃO EM CIÊNCIAS BIOLÓGICAS
• Palavras-chave em Português: Ansiedade; Núcleo dorsal da rafe; Serotonina; Receptores 5-HT3; Fêmeas; CNPQ::CIENCIAS BIOLOGICAS
• Link de acesso: https://repositorio.ufrn.br/jspui/handle/123456789/22003

The involvement of both 5-HT3 receptors and dorsal raphe nucleus in the modulation of anxiety has been presented in the literature. Considering that most of population is affected by anxiety disorders, it is essential to search for new and more efficient forms of treatment and to increase the knowledge on the subject. The aim of this study is to test the hypothesis that the 5-HT3 receptors in the dorsal part of the dorsal raphe nucleus (dNDR) modulates the responses related to anxiety in rats. In experiment one, female Wistar rats with ± 90 days old were treated (p.o.) with ondansetron at doses of 0.1, 1 and 10 mg/kg/mL and 60 minutes later, were submitted to the elevated T maze (ETM) test. 24 hours later, they received ondansetron and were submitted to the open Field Test. In the experiments 2 and 3, the rats were submitted to the stereotactic surgery for implantation of intra-NDR cannula and received administration (via infusion) of saline or dolasetron at doses of 100, 500 and 1000nmol (experiment 2) or saline or mCPBG at doses of 2.5, 5 and 10mg (experiment 3). In both experiments, 5 minutes after the infusion of the drug, the animals were submitted to the test of ETM, and 24 hours after, they received drug infusion and were submitted to the open field test, to obtain dose-response curves. Ondansetron at a dose of 10mg/kg/mL increased latency of escape response in ETM, suggesting an panicolytic-like effect. The dolasetron caused no effect in ETM test in any of the tested doses. The agonist mCPBG instead, increased the inhibitory avoidance latency in all doses, suggesting an anxiogenic-like effect. Data obtained in the open field test showed no change in locomotor activity of rats following the treatments. The data here obtained supports the importance of 5-HT3 receptors in the NDR in the modulation of anxiety.