Efeito do tratamento com escitalopram sobre as alterações emocionais decorrentes do estresse neonatal em ratos Wistar adolescentes machos e fêmeas e as consequências de manipulações no período neonatal sobre o comportamento materno

• Ano de defesa: 2018
• Autor(a) principal: Zanta, Natalia Cristina [UNIFESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo (UNIFESP)
• Palavras-chave em Português: Maternal deprivation; Animal model; Escitalopram; Affective behaviour; Corticosterone; Sexual differences; Privação materna; Modelo animal; Comportamento emocional; Corticosterona; Diferenças sexuais
• Link de acesso: https://sucupira.capes.gov.br/sucupira/public/consultas/coleta/trabalhoConclusao/viewTrabalhoConclusao.jsf?popup=true&id_trabalho=6315023; https://repositorio.unifesp.br/handle/11600/52895

Early life adversities may lead to long-term behavioural and hormonal changes, due to immaturity of the central nervous system, resulting in increased vulnerability to stressful events. In rodents, there is a developmental phase, between postnatal days (PNDs) 4 and 14, characterized by low corticosterne stress reactivity, the stress hyporesponsive period (SHRP). Maternal deprivation (DEP) on PND 9, leads to altered depressive- and anxiety-like behaviours, in addition to unbalanced serotoninergic activity, in adolescent and adult male and female rats. In the present study, we tested the hypothesis that chronic treatment with escitalopram (ESC), the most specific selective serotonin reuptake inhibitor, would normalize these altered behaviours. To this end, whole litters were standardized to four males and four females, and either kept with their mother throughout development (control, CTL) or DEP on PND 9 (DEP9). On PND 10, 2 h before the end of the deprivation period or at the appropriate time for CTL pups, half of the total number of litters in each group received a saline injection (SAL stress) or not (NSAL), making up for the four main groups: CTL-NSAL, CTL-SAL, DEP9-NSAL, DEP9-SAL. Following these procedures, litters were reunited with their mothers and maternal behaviour was assessed 3 times during PND 10, at 10:00 h, 14:00 h and 17:30 h. Weaning took place on PND 21, and administration of vehicle (2 males and 2 females) or ESC (2 males and 2 females) began and lasted for 24 days; treatment was the intra-litter variable. After 21 days of treatment, 1 male and 1 female in each treatment were non-tested (basal corticosterone levels) and the other animals were submitted to several tests of emotionality, without interruption of the pharmacological treatment. Immediately after the last test, blood samples were taken for determination of corticosterone stress levels. The results showed that DEP9, alone or in combination with SAL increased maternal behaviour. Neonatal manipulations did not change parameters in the open field test but were anxyogenic for females in the elevated plus maze. ESC increased social investigation only in males and SAL produced a pro-depressive effect in the forced swimming test in males. The behavioural tests elicited a corticosterone response in males, but not in females. Based on these results we conclude that neonatal manipulations increased maternal behaviour and that alterations in late adolescence were sex-dependent. The pharmacological treatment produced a positive effect only in the social investigation test and, therefore, was not effective in improving the behavioural changes induced by maternal deprivation.