Os efeitos da submissão ao Chronic Mild Stress (CMS) no estabelecimento de uma discriminação

• Ano de defesa: 2013
• Autor(a) principal: Rocha, Laura Muniz
• Orientador(a): Micheletto, Nilza
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Pontifícia Universidade Católica de São Paulo
• Programa de Pós-Graduação: Programa de Estudos Pós-Graduados em Psicologia Experimental: Análise do Comportamento
• Departamento: Psicologia
• País: BR
• Palavras-chave em Português: Chronic Mild Stress; CMS; Discriminação; Teste de generalização
• Palavras-chave em Inglês: Discrimination; Generalization testing
• Área do conhecimento CNPq: CNPQ::CIENCIAS HUMANAS::PSICOLOGIA::PSICOLOGIA EXPERIMENTAL
• Link de acesso: https://tede2.pucsp.br/handle/handle/16712

Chronic Mild Stress (CMS) is an experimental animal model of induced anhedonia by exposing rats to a protocol of mild stressors for a long period of time. This model is an attempt to reproduce in controlled environment conditions analogous to the real environment, seen as important to produce behavioral changes. To identify other effects of exposure to CMS, this study aimed to verify whether the exposure to chronic mild stress produces changes in the establishment of a simple discrimination after the expouse to the protocol. Therefore, the subjects of this study had their weight and food and water intake measured daily, tests of consumption and preference of liquid were realized weekly; subjects were exposed to the protocol stressors over six weeks and, after this period was initiated the discriminative training. The experiment consisted of four experimental conditions: (1) one subject was exposed, like all other subjects, to tests of consumption and preference of liquids, (2) four subjects were exposed to the protocol, (3) four subjects were exposed to the protocol and to a discrimination procedure(4) four subjects were exposed only to the discrimination procedure and they weren t exposoused to the chronic mild stress. The results obtained in this study indicate that: (a) subjects exposed to the protocol showed a greater loss and variation of the body weight; (b) during the protocol the average of water consumption increased and average food consumption decreased for subjects exposed to the protocol. (c) tests of consumption and preference of liquids did not show a reduction in preference for the sucrose subtance but an increase in the total fluid intake for subjects exposed to stress. And, finally, (d) observed that exposure protocol stressors interfere with the acquisition of a simple discrimination. For subjects exposed to the protocol were required, on average, twice as many sessions to reach the criterion of two consecutive sessions with discriminative indices above 80%. and (e) that the subjects exposed to the protocol showed differences in tests of generalization when compared with subjects exposed only to discrimination. And, lastly (d) observed that exposure to the protocol interfered the acquisition of a simple discrimination. The subjects exposed to the protocol required, on average, twice as many sessions to reach the criterion of two consecutive sessions with discriminative indices above 80% and (e) the subjects exposed to the protocol showed differences in the generalization tests when compared with subjects exposed only to discrimination.Thereby, the exposure to a condition of chronic mild stress and affects the acquisition of a simple discrimination established after the protocol. This result may indicate that exposure to stress condition altered the reinforcing value of the stimulus for the subjects who were exposed to it, this change may have been responsible for the differences obtained in the discrimination of subjects exposed to this condition and subjects who were not exposed to the protocol