Associa??o entre exposi??o ao estresse precoce e a cogni??o na vida adulta : vulnerabilidade, resili?ncia e epigen?tica

• Ano de defesa: 2016
• Autor(a) principal: Albuquerque Filho, Manoel Os?rio
• Orientador(a): Schr?der, Nadja
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Pontif?cia Universidade Cat?lica do Rio Grande do Sul
• Programa de Pós-Graduação: Programa de P?s-Gradua??o em Biologia Celular e Molecular
• Departamento: Faculdade de Bioci?ncias
• País: Brasil
• Palavras-chave em Português: ESTRESSE; COGNI??O; MEM?RIA; BIOLOGIA MOLECULAR; BIOLOGIA CELULAR
• Área do conhecimento CNPq: CIENCIAS BIOLOGICAS::BIOLOGIA GERAL
• Link de acesso: http://tede2.pucrs.br/tede2/handle/tede/6876

Exposure to stressful events early in life may have permanent deleterious consequences on nervous system function and increase the susceptibility to cognitive impairment later in life. Maternal deprivation, commonly used as a source of early life stress, impairs memory in adult rats and reduces hippocampal brain-derived neurotrophic factor (BDNF) levels in a very heterogeneous way among individuals. The aim of the present study was to investigate the possible epigenetic modulation underlying recognition memory impairment and reduced BDNF levels in the hippocampus of adult maternal deprived rats. We also evaluated the potential ameliorating properties of the histone deacetylase (HDAC) inhibitor, sodium butyrate, on memory deficits and BDNF changes associated with maternal deprivation. For this study, maternal deprived animals were categorized as ?inferior learners? and ?superior learners? according to their performance in novel object recognition memory task. Results indicated that HDAC activity was higher in individuals submitted to maternal deprivation with the worst cognitive performance (inferior learners). Acute administration of sodium butyrate increased histone H3 acetylation and BDNF levels, and restored recognition memory in maternally deprived animals with the worst cognitive performance. Moreover, we also showed that there is a positive correlation between BDNF levels and memory performance. Taken together, the results indicated that HDAC inhibitors could be considered as a possible therapeutic agent to improve cognitive performance in inferior learners individuals. Further studies need to be conducted for a better understanding of the mechanisms associated with persistent alterations observed in adult life induced by early stressful events and those leading to resilience.