Navegando por Palavras-chave "Recompensa"
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- ItemAcesso aberto (Open Access)Consequências do estresse de derrota social (episódico e contínuo) sobre os efeitos psicomotores e reforçadores condicionados da nicotina em camundongos(Universidade Federal de São Paulo (UNIFESP), 2016-02-29) Domingues, Liz Paola [UNIFESP]; Quadros, Isabel Marian Hartmann de [UNIFESP]; http://lattes.cnpq.br/3982014468609862; http://lattes.cnpq.br/2626872911089070; Universidade Federal de São Paulo (UNIFESP)Objective: This study aimed to investigate the consequences of two types of repeated social defeat stress (episodic and continuous) on nicotine-induced psychomotor effects and conditioned reward in mice. Methods: Using the resident-intruder model, experimental mice (intruder) were defeated by an aggressive one (resident). After each daily defeat, intruders returned to their homecage (episodic stress) or cohabitated with the aggressor for 24h (continuous stress), until the next defeat. After the 10-day stress protocol, different batches of mice received nicotine (0.1 mg/kg, s.c.) in locomotor tests (short- and long-term), or for conditioned place preference (CPP). Results: Both defeat protocols induced short-term (within 24h) locomotor suppression, which was potentiated by nicotine only after continuous defeat stress. Ten days after the final defeat, locomotor suppression was no longer observed due to stress or nicotine. Nicotine failed to induce place preference or aversion after either defeat protocol. Only the episodic defeat group showed nicotine-induced locomotor suppression one week after the additional nicotine exposure during the CPP protocol. Conclusion: Our findings indicate that different consequences of episodic and continuous stress on nicotine psychomotor effects were observed shortly after stress. Differential long-term effects on nicotine locomotor response were only observed when stressed mice were further exposed to repeated nicotine administration (during CPP). Also, neither episodic nor continuous defeat stress facilitated the acquisition of conditioned place preference or aversion to nicotine.
- ItemAcesso aberto (Open Access)Efeito de antagonista do receptor do fator liberador de corticotrofina do tipo 1 (CRFR1) sobre as fases do condicionamento de preferência por local induzido pelo álcool em camundongos machos e fêmeas(Universidade Federal de São Paulo, 2022-03-31) Sorigotto, Beatriz Déo [UNIFESP]; Quadros, Isabel Marian Hartmann de [UNIFESP]; http://lattes.cnpq.br/3982014468609862; http://lattes.cnpq.br/3016164498750594O Fator Liberador de Corticotrofina (Corticotropin Releasing Factor - CRF) é classicamente conhecido por seu papel em modular respostas a estressores, principalmente através da ativação de seus receptores do tipo 1 (CRFR1). As drogas de abuso, inclusive o álcool (consumido na forma de etanol), estimulam a sinalização do sistema CRF tanto em áreas hipotalâmicas, como em regiões do sistema encefálico de recompensa. Assim, os efeitos reforçadores do álcool, bem como os comportamentos relacionados a transtornos por uso de álcool, envolvem uma sobreposição dos sistemas cerebrais de estresse e recompensa. Notase, ainda, importantes diferenças sexuais quanto aos processos que envolvem a dependência. No presente estudo, investigamos se o bloqueio de receptores CRFR1 poderia interferir na expressão e reinstalação da preferência condicionada induzida por álcool em camundongos machos e fêmeas, utilizando o modelo de Condicionamento de Preferência por Local (Conditioned Place Preference, CPP). Para isso, utilizamos camundongos suíços machos e fêmeas adultos, que receberam administração de álcool (2,0 g/kg, i.p.) ou salina durante 8 sessões de condicionamento. Então, o antagonista de CRFR1 (CP-154,526, i.p.) foi administrado antes da sessão de teste (expressão do CPP); ou antes da sessão de reinstalação induzida por priming de álcool, após a extinção da preferência condicionada. Nossos resultados sugerem que o CP-154,526 bloqueou a reinstalação da preferência condicionada induzida por priming de álcool em camundongos machos, mas não em fêmeas. A expressão do CPP ao álcool não foi afetada pela administração do antagonista em nenhum dos sexos, com uma redução moderada na atividade locomotora de machos e fêmeas. Também foi observado que as fêmeas reinstalaram a preferência condicionada ao álcool com uma dose menor de priming da droga (1,0 g/kg) em relação aos machos (1,5 g/kg). Assim, a sinalização do sistema CRF através de seus receptores CRFR1 parece mediar a reinstalação da preferência condicionada ao álcool no paradigma do CPP, de maneira dependente do sexo.
- ItemAcesso aberto (Open Access)Práticas alimentares maternas não nutritivas entre crianças brasileiras : associações com características da mãe e da criança(Universidade Federal de São Paulo (UNIFESP), 2017-11-24) Ivers, Julia Feltrin [UNIFESP]; Taddei, José Augusto de Aguiar Carrazedo [UNIFESP]; Moraes, Denise Ely Bellotto de [UNIFESP]; http://lattes.cnpq.br/1215366717214275; http://lattes.cnpq.br/7949679002889518; http://lattes.cnpq.br/1732567188661694; Universidade Federal de São Paulo (UNIFESP)Introduction: The marked increase in the prevalence of overweight and childhood obesity is a worldwide public health problem that affects more diverse ethnicities and socioeconomic groups around the world. In Brazil, there is a clear change in the nutritional profile of children in the last decades, from underweight to overweight, especially in the age group between 5 and 9 years This expressive increase in the rates of childhood obesity is related to environmental changes that lead to a high caloric intake and low energy expenditure. In this obesogenic environment, the strategies used by parents to feed their children represent an important part of the environmental factors that directly affects the formation of eating habits and weight status of the child. The study of feeding practices through which mothers feed their children in order to regulate negative emotions, reward or punish child's behavior is described in the literature as non-nutritive eating practices. In this situation, the foods used are commonly palatable and of high energy density. Some studies on the issue show associations of these parental feeding practices with the development in the child of eating behaviors that leads to the weight gain. Considering that mothers are essentially responsible for child feeding and have an important role in shaping eating habits and child‟s food environment, it is relevant to understand which characteristics of the mother-child dyad are associated with these practices. The aim of this study was to investigate the associations between non-nutritive maternal feeding practices and sociodemographic, anthropometric, dietary and attitudinal characteristics of Brazilian mothers and their children. Methods: This is a cross-sectional observational study conducted with mothers and their two-to-eight-year-old children enrolled in private schools of São Paulo and Campinas, SP, Brazil. Non-nutritive feeding practices used by the mothers were assessed by the “Emotion regulation/Food as reward” factor of the Brazilian version of the Comprehensive Feeding Practices Questionnaire (CFPQ). Sociodemographic, anthropometric, dietary and attitudinal characteristics were self-reported by the mothers. Results: Mothers with lower age and who perceived their child as a little thin or very thin were more prone to feed them with non-nutritive practices. Child‟s characteristics such as preschool age, greater ultra-processed food intake, and overweight or obesity were also found to be associated with increased maternal use of non-nutritive feeding practices. Contrary to our expectations, maternal weight status and child sex were not associated to these feeding practice. Conclusion: The associations in this study allowed us to identify risk groups for non-nutritive feeding practices based on maternal and child characteristics. The results showed that different factors, objective and subjective, may influence the use of non-nutritive feeding practices. Clinical interventions should be done to help mothers to find alternatives to deal with child´s emotions and behaviors other than offering foods.