Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-10T22:31:40Z No. of bitstreams: 1 JarmillaBowLtaifGarcia_DISSERT.pdf: 1132092 bytes, checksum: 73425ef0ae6509211c5362da756e1308 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-05-17T19:56:28Z (GMT) No. of bitstreams: 1 JarmillaBowLtaifGarcia_DISSERT.pdf: 1132092 bytes, checksum: 73425ef0ae6509211c5362da756e1308 (MD5) / Made available in DSpace on 2016-05-17T19:56:28Z (GMT). No. of bitstreams: 1 JarmillaBowLtaifGarcia_DISSERT.pdf: 1132092 bytes, checksum: 73425ef0ae6509211c5362da756e1308 (MD5) Previous issue date: 2015-06-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A ansiedade ? um estado emocional caracterizado por altera??es fisiol?gicas e psicol?gicas que oferecem uma sensa??o desagrad?vel ao indiv?duo. No entanto esse comportamento tem grande valor adaptativo, uma vez que alerta o indiv?duo sobre os poss?veis perigos que determinada situa??o possa oferecer. J? foram identificadas v?rias regi?es encef?licas relacionadas ao substrato neural da ansiedade e dentre elas pode-se citar a subst?ncia cinzenta periaquedutal (SCP). Al?m disso, diversos estudos demonstraram o envolvimento do sistema seroton?rgico da por??o dorsal da SCP (SCPD) na modula??o de comportamentos relativos ? ansiedade. Tendo em vista isso, o objetivo desse trabalho foi avaliar o papel dos receptores 5-HT3 da SCPD na modula??o de comportamentos relacionados ? ansiedade e locomo??o em ratos testados no labirinto em cruz elevado (LCE) e no campo aberto (CA). Ratos Wistar receberam a microinje??o do antagonista do receptor 5-HT3 dolasetron (100ng, 500ng e 1000ng) (experimento 1), do agonista do receptor 5-HT3m-Chlorophenylbiguanide (mCPBG) (2,5?g, 05?g e 10?g) (experimento 2) ou de salina a 0,9% na SCPD. Ap?s 10 minutos (experimento 1) ou 5 minutos (experimento 2), os ratos foram colocados no LCE e seus comportamentos foram avaliados durante 5 minutos. Vinte e quatro horas depois, os animais receberam as mesmas doses com que foram microinjetados no dia anterior na SCPD e ap?s 10 minutos (experimento 1) ou 5 minutos (experimento 2) foram colocados no CA e seus comportamentos foram avaliados durante 15 minutos. No experimento 1 a microinje??o do dolasetron n?o alterou os par?metros de ansiedade e locomo??o no LCE e CA. J? no experimento 2, o mCPBG nas doses de 5?g e de 10?g produziu efeito ansiol?tico no LCE sem promover altera??o locomotora no animal. Esses resultados sugerem que a ativa??o dos receptores 5-HT3 da SCPD favorece um efeito ansiol?tico em ratos avaliados no LCE. / Anxiety is an emotional state characterized by physiological and psychological changes that provide an unpleasant feeling to the individual. However this behavior has great adaptive value, since it alerts the individual about possible dangers that particular situation can offer. It has been identified various brain regions related to neural substrate of anxiety and, among them, it is the periaqueductal gray matter (PAG). Several studies have demonstrated the involvement of serotonergic system of the dorsal portion of PAG (DPAG) in the modulation of behaviors related to anxiety. In view of this, the objective of this study was to evaluate the role of 5-HT3 receptors of the DPAG in the modulation of behaviors related to anxiety and locomotion in rats tested in the elevated plus maze (EPM) and open field (OF). Wistar rats received microinjection of 5-HT3 receptor antagonist dolasetron (100ng, 500ng and 1000ng) (experiment 1), 5-HT3 receptor agonist m-Chlorophenylbiguanide (mCPBG) (2,5?g, 5?g and 10mg) (Experiment 2) or saline 0.9% in the DPAG. After 10 minutes (experiment 1) or 5 minutes (Experiment 2), the rats were placed in the EPM and their performances were evaluated during 5 minutes. Twenty-four hours later the animals received the same doses that were microinjected on the previous day in the DPAG and after 10 minutes (experiment 1) or 5 minutes (experiment 2) were placed in OF and their behaviors were assessed for 15 minutes. In experiment 1 microinjection of dolasetron did not change the parameters of anxiety and locomotion in EPM and OF. In the experiment 2, the mCPBG at doses of 5?g and 10mg produced anxiolytic effect in EPM without changes in locomotor behavior. These results suggest that activation of 5-HT3 receptors in the SCPD eliciate an anxiolytic effect in rats evaluated in EPM.