Efeitos da restricao calorica sobre a formacao da memoria discriminativa aversiva em camundongos adultos ou idosos
Data
2013
Autores
Andrade, Fernanda Talhati Castro 
Orientadores
Frusa Filho, Roberto
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
A restricao calorica (RC) parece ser o unico procedimento experimental capaz de aumentar a expectativa de vida em roedores. Alem disso, evidencias experimentais tem demonstrado que a RC e capaz de atenuar os efeitos amnesticos promovidos pelo envelhecimento. Contudo, poucos estudos avaliaram sistematicamente os efeitos da RC sobre a formacao da memoria em camundongos adultos (com 3 meses de idade) ou idosos (com mais de 18 meses de idade). Dessa forma, o objetivo do presente estudo foi avaliar os efeitos da RC aguda (12 h/dia durante a fase escura) ou intermitente (12 h/dia por 2 dias) sobre o aprendizado e a memoria de camundongos avaliados na esquiva discriminativa em labirinto em cruz elevado (ED-LCE), um modelo que e capaz de avaliar simultanea, mas independentemente, o aprendizado, a memoria e os niveis de ansiedade e atividade locomotora em roedores. Alem disso, os efeitos da RC sobre a concentracao de corticosterona tambem foram avaliados. Camundongos Swiss machos adultos (3 meses de idade) ou idosos (18-24 meses) receberam alimentacao ad libitum (condicao controle) ou foram restritos de alimentacao agudamente durante a fase escura (RC 12 h/dia) ou de maneira intermitente (RC 12 h/2 dias). Os protocolos de RC foram aplicados imediatamente antes ou apos o treino ou imediatamente antes do teste. Nossos resultados demonstraram que a RC intermitente (12 h/2 dias) aumentou a persistencia da memoria quando aplicada antes do treino em camundongos adultos e antes do teste em camundongos idosos. Por outro lado, a RC promoveu prejuizo na consolidacao per se e nao modificou a evocacao. Esses efeitos cognitivos nao parecem estar associados ao aumento dos niveis plasmaticos de corticosterona induzidos pela RC. Em conjunto, nossos resultados indicam que a RC intermitente promove efeitos promnesticos nao apenas em camundongos idosos, mas tambem em adultos
ABSTRACT Caloric restriction (CR) seems to be the unique experimental manipulation that leads to a remarkable increase in lifespan in rodents. Evidences have suggested that CR can enhance memory in distinct animal models mainly during aging. However, only a few studies systematic evaluated the effects CR on memory formation in both adult (3monthold) and aged (1824monthold) mice. Thus, the aim of the present study was to investigate the effects of acute (12 h) or intermittent (12 h/day for 2 days) CR protocols on learning and memory of adult and aged mice evaluated in the plusmaze discriminative avoidance task (PMDAT), an animal model that concurrently (but independently) evaluates learning and memory, anxiety and locomotion. We also investigated the possible role of CRinduced stress by the corticosterone concentration in adult mice. Male mice were kept at home cage with food ad libitum (CTRL – control condition) or subjected to CR during the dark phase of the cycle for 12 h/day or 12 h/2 days. The CR protocols were applied before training, immediately after it or before testing. Our results demonstrated that only intermittent CR enhanced memory persistence when applied before training in adults and before testing in aged mice. Conversely, intermittent CR impaired consolidation and exerted no effects on retrieval irrespective of age. These effects do not seem to be related to corticosterone concentration. Collectively, these results indicate that intermittent CR can promote promnestic effects not only in aged mice but also in adults.
ABSTRACT Caloric restriction (CR) seems to be the unique experimental manipulation that leads to a remarkable increase in lifespan in rodents. Evidences have suggested that CR can enhance memory in distinct animal models mainly during aging. However, only a few studies systematic evaluated the effects CR on memory formation in both adult (3monthold) and aged (1824monthold) mice. Thus, the aim of the present study was to investigate the effects of acute (12 h) or intermittent (12 h/day for 2 days) CR protocols on learning and memory of adult and aged mice evaluated in the plusmaze discriminative avoidance task (PMDAT), an animal model that concurrently (but independently) evaluates learning and memory, anxiety and locomotion. We also investigated the possible role of CRinduced stress by the corticosterone concentration in adult mice. Male mice were kept at home cage with food ad libitum (CTRL – control condition) or subjected to CR during the dark phase of the cycle for 12 h/day or 12 h/2 days. The CR protocols were applied before training, immediately after it or before testing. Our results demonstrated that only intermittent CR enhanced memory persistence when applied before training in adults and before testing in aged mice. Conversely, intermittent CR impaired consolidation and exerted no effects on retrieval irrespective of age. These effects do not seem to be related to corticosterone concentration. Collectively, these results indicate that intermittent CR can promote promnestic effects not only in aged mice but also in adults.
Descrição
Citação
ANDRADE, Fernanda Talhati Castro. Efeitos da restrição calórica sobre a formação da memória discriminativa aversiva em camundongos adultos ou idosos. 2013. 99f. Dissertação (Mestrado em Farmacologia) – Escola Paulista de Medicina, Universidade Federal de São Paulo. São Paulo, 2013.