Caracterização de comportamentos hedônicos em um modelo animal de esquizofrenia: a linhagem SHR (Spontaneously Hypertensive Rat)
Data
2015-10-31
Autores
Gouvea, Douglas Albuquerque 
Orientadores
Abilio, Vanessa Costhek
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Objetivo: Caracterizar o comportamento hedônico consumatório e antecipatório na linhagem SHR e estender a avaliação do comportamento social da linhagem. Métodos: Para a caracterização do comportamento hedônico consumatório foi utilizado o Teste de Preferência por Sacarose em duas versões diferentes, permitindo uma análise pontual (Protocolo 1) e outra prolongada (Protocolo 2) do comportamento. Foi calculada porcentagem de preferência pela sacarose em relação a água através da mensuração do consumo de sacarose em ambos os protocolos. Com relação a caracterização do comportamento antecipatório foram utilizados os Testes de Contraste Positivo e de Contraste Negativo. A capacidade do animal antecipar e adaptar seu comportamento ao novo estímulo foi avaliado pelo tempo de consumo da solução de sacarose. Para estender a avaliação do comportamento social foi utilizado o Teste de Investigação Social. Foi observado o tempo de investigação entre o estímulo social e o estímulo neutro apresentado. Em todos os testes os animais SHR tinham de 3 a 5 meses e foram comparados com a linhagem Wistar como controle. Resultados: Ambos os testes de Preferência por Sacarose revelaram um aumento da preferência por sacarose em relação a água (estímulo neutro). Sendo que observou-se um possível déficit na linhagem SHR na capacidade de atribuir um valor a recompensa no protocolo 1. Já no protocolo 2 a linhagem SHR apresentou uma preferência continua pela sacarose, enquanto que a linhagem Wistar demonstrou um desinteresse pela sacarose ao longo do tempo. Os testes de contraste a principio evidenciaram que tanto a linhagem Wistar quanto a linhagem SHR percebem a mudança no valor da recompensa, contudo a linhagem SHR parece apresentar um consumo mais elevado quando a sua expectativa é mais baixa. Além disso, parece que os SHR não captam mudanças mais sutis nos valores de recompensa esperadas. O teste de investigação social apontou um déficit na investigação social, apresentando menor interesse e motivação ao investigar um estímulo social novo, quando comparado ao grupo controle. Conclusões: A caracterização dos comportamentos hedônicos na linhagem SHR revelou alterações no comportamento consumatório, a linhagem prefere mais a sacarose, que os Wistar. E parece perceber estímulos prazerosos de grande valência de forma errônea, atribuindo uma saliência exacerbada dele. Essas características podem modelar alterações em portadores de esquizofrenia, já que o ser humano com esse transtorno parece dar saliências erradas a estímulos ambientais. O déficit na investigação social, vai de encontro com dados prévios de nosso modelo, e fortalece a capacidade de mimetizar a sintomatologia negativa presente na esquizofrenia.
Objective: To characterize the consummatory and anticipatory hedonic behavior in the SHR strain and extend the evaluation of the social behavior of the lineage. Methods: For the characterization of hedonic consummatory behavior was used the Sucrose Preference Test in two different versions, allowing a punctual analysis (Protocol 1) and another prolonged analysis (Protocol 2) behavior. Percentage was calculated by the sucrose preference against water preference by measuring the sucrose intake in both protocols. Regarding the characterization of anticipatory behavior the Contrast Tests Positive and Negative Contrast were used. The animal's ability to anticipate and adapt their behavior to the new stimulus was evaluated by the time consumption of sucrose solution. To extend the evaluation of the social behavior, social investigation was used for test. It was observed between time to investigate the social stimulus and the neutral stimulus presented. In all tests, the SHR were 3 to 5 months and were compared with Wistar as control. Results: Both Sucrose Preference Tests showed an increased preference for sucrose relative to water (neutral stimulus). There was a possible deficit in the SHR strain on the ability to assign a value to reward the Protocol 1. In the Protocol 2 the SHR strain showed a continue preference for sucrose, while the Wistar demonstrated a lack of interest in sucrose along the time. Contrast tests at first showed that both the Wistar as the SHR realize the shift in reward value, however the SHR strain appears to have a higher consumption when their expectations are lower. Moreover, it seems that the SHR do not capture more subtle changes in the expected reward values. The social research test showed a deficit in social research, with lower interest and motivation to investigate a new social stimulation, when compared to control group. Conclusions: The characterization of hedonic behavior in the SHR strain revealed changes in consummator behavior; the strain prefers more sucrose, than the Wistar. And seems to realize large pleasurable stimuli valence wrongly attributing an exacerbated salience. These characteristics can model changes in patients with schizophrenia, as humans with this disorder seem to give wrong salience to environmental stimuli. The deficit in social research, meets with previous data from our model, and strengthens the capacity to mimic negative symptoms present in schizophrenia.
Objective: To characterize the consummatory and anticipatory hedonic behavior in the SHR strain and extend the evaluation of the social behavior of the lineage. Methods: For the characterization of hedonic consummatory behavior was used the Sucrose Preference Test in two different versions, allowing a punctual analysis (Protocol 1) and another prolonged analysis (Protocol 2) behavior. Percentage was calculated by the sucrose preference against water preference by measuring the sucrose intake in both protocols. Regarding the characterization of anticipatory behavior the Contrast Tests Positive and Negative Contrast were used. The animal's ability to anticipate and adapt their behavior to the new stimulus was evaluated by the time consumption of sucrose solution. To extend the evaluation of the social behavior, social investigation was used for test. It was observed between time to investigate the social stimulus and the neutral stimulus presented. In all tests, the SHR were 3 to 5 months and were compared with Wistar as control. Results: Both Sucrose Preference Tests showed an increased preference for sucrose relative to water (neutral stimulus). There was a possible deficit in the SHR strain on the ability to assign a value to reward the Protocol 1. In the Protocol 2 the SHR strain showed a continue preference for sucrose, while the Wistar demonstrated a lack of interest in sucrose along the time. Contrast tests at first showed that both the Wistar as the SHR realize the shift in reward value, however the SHR strain appears to have a higher consumption when their expectations are lower. Moreover, it seems that the SHR do not capture more subtle changes in the expected reward values. The social research test showed a deficit in social research, with lower interest and motivation to investigate a new social stimulation, when compared to control group. Conclusions: The characterization of hedonic behavior in the SHR strain revealed changes in consummator behavior; the strain prefers more sucrose, than the Wistar. And seems to realize large pleasurable stimuli valence wrongly attributing an exacerbated salience. These characteristics can model changes in patients with schizophrenia, as humans with this disorder seem to give wrong salience to environmental stimuli. The deficit in social research, meets with previous data from our model, and strengthens the capacity to mimic negative symptoms present in schizophrenia.
Descrição
Citação
GOUVEA, Douglas Albuquerque. Caracterização de comportamentos hedônicos em um modelo animal de esquizofrenia: a linhagem SHR (Spontaneously Hypertensive Rat). 2015. 66 f. Dissertação (Mestrado em Farmacologia) - Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), São Paulo, 2015.