Estudo das alterações morfofisiológicas no hipocampo de ratos idosos submetidos a um programa de exercício físico aeróbico
Carregando...
Data
2024-03-14
Autores
Rocha, Paulo Ricardo [UNIFESP]
Orientadores
Arida, Ricardo Mario [UNIFESP]
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Objetivo: Este estudo visa investigar as alterações morfofisiológicas do hipocampo de ratos idosos, envelhecidos naturalmente, divididos em dois grupos: sedentários e submetidos a um programa de exercício físico aeróbico. Métodos: Foram utilizados dez ratos Wistar com 18 meses de idade, cinco controles sedentários e cinco que realizaram treinamento físico em esteira por oito semanas. Após a eutanásia e obtenção das amostras de hipocampo, foram preparadas lâminas para análise histológica. Dez lâminas selecionadas por sorteio foram submetidas a três métodos histoquímicos – azul da Prússia de Perls, impregnação argêntica de GallyasBraak e Congo Red, para quantificação, através do método estereológico, da densidade numérica de neurônios piramidais, neurônios granulares, oligodendrócitos e micróglia (pelo fracionador óptico) e do volume de placas senis compostas pelo peptídeo beta-amiloide e emaranhados neurofibrilares constituídos por proteína tau hiperfosforilada (pelo método de Cavalieri). A análise estatística foi realizada por meio do teste t de Student e da correlação de Pearson. Resultados: A avaliação da diferença entre as médias de número de células e volume de substâncias demonstrou que o grupo exercício apresentou maior número de neurônios piramidais (p = 0,006), neurônios granulares (p =0,003) e oligodendrócitos (p = 0,034) saudáveis em relação ao grupo controle. Ainda, houve diminuição do número de neurônios com a presença de emaranhados neurofibrilares (p = 0,001) e do volume de placas amiloide (p = 0,001), bem como de oligodendrócitos degenerados (p = 0,003) e micróglia fagocitária (p = 0,039). Das correlações, destacase a correlação forte e positiva entre os números de neurônios piramidais e granulares normais em ambos os grupos e a correlação forte e positiva entre o número de neurônios granulares afetados por ptau e micróglia fagocitária no grupo controle. Houve, também, correlação forte e negativa entre o número oligodendrócitos senescentes e volume de emaranhados neurofibrilares no grupo exercício e correlação forte e negativa entre o número oligodendrócitos senescentes e volume de placas senis no grupo controle. Conclusões: Esses achados demonstram o efeito neuroprotetor exercido pela atividade física de intensidade moderada no que diz respeito à degeneração morfofisiológica do hipocampo relacionada ao envelhecimento. A observação integrada dos principais marcadores de neurodegeneração, do acúmulo de ferro e da atividade microglial fornece um panorama geral do comportamento do hipocampo em resposta à intervenção realizada.
Objective: This study aims to investigate the morphophysiological changes in the hippocampus of elderly rats, aged naturally, divided into two groups: sedentary and undergoing an aerobic physical exercise program. Methods: Ten 18monthold Wistar rats were used, five sedentary controls and five that performed physical training on a treadmill for eight weeks. After euthanasia and obtaining hippocampal samples, slides were prepared for histological analysis. Ten slides selected by draw were subjected to three histochemical methods – Perls Prussian blue, GallyasBraak argent impregnation and Congo Red, for quantification, through the stereological method, of the numerical density of pyramidal neurons, granule neurons, oligodendrocytes and microglia (by the optical fractionator) and the volume of senile plaques composed of βamyloid peptide and neurofibrillary tangles composed of hyperphosphorylated tau protein (by the Cavalieri method). Statistical analysis was performed using Student's t testand Pearson's correlation. Results: The evaluation of the difference between the average number of cells and volume of substances demonstrated that the exercise group presented a greater number of healthy pyramidal neurons (p = 0.006), granule neurons (p = 0.003) and oligodendrocytes (p = 0.034) in compared to the control group. Furthermore, there was a decrease in the number of neurons with the presence of neurofibrillary tangles (p = 0.001) and the volume of amyloid plaques (p = 0.001), as well as degenerated oligodendrocytes (p =0.003) and phagocytic microglia (p = 0.039). Of the correlations, the strong and positive correlation between the numbers of normal pyramidal and granule neurons in both groups and the strong and positive correlation between the number of granule neurons affected by ptau and phagocytic microglia in the control group stand out. There was also a strong and negative correlation between the number of senescent oligodendrocytes and the volume of neurofibrillary tangles in the exercise group and a strong and negative correlation between the number of senescent oligodendrocytes and the volume of senile plaques in the control group. Conclusions: These findings demonstrate the neuroprotective effect exerted by moderateintensity physical activity regarding agingrelated morphophysiological degeneration of the hippocampus. The integrated observation of the main markers of neurodegeneration, iron accumulation and microglial activity provides a general overview of the behavior of the hippocampus in response to the intervention performed.
Objective: This study aims to investigate the morphophysiological changes in the hippocampus of elderly rats, aged naturally, divided into two groups: sedentary and undergoing an aerobic physical exercise program. Methods: Ten 18monthold Wistar rats were used, five sedentary controls and five that performed physical training on a treadmill for eight weeks. After euthanasia and obtaining hippocampal samples, slides were prepared for histological analysis. Ten slides selected by draw were subjected to three histochemical methods – Perls Prussian blue, GallyasBraak argent impregnation and Congo Red, for quantification, through the stereological method, of the numerical density of pyramidal neurons, granule neurons, oligodendrocytes and microglia (by the optical fractionator) and the volume of senile plaques composed of βamyloid peptide and neurofibrillary tangles composed of hyperphosphorylated tau protein (by the Cavalieri method). Statistical analysis was performed using Student's t testand Pearson's correlation. Results: The evaluation of the difference between the average number of cells and volume of substances demonstrated that the exercise group presented a greater number of healthy pyramidal neurons (p = 0.006), granule neurons (p = 0.003) and oligodendrocytes (p = 0.034) in compared to the control group. Furthermore, there was a decrease in the number of neurons with the presence of neurofibrillary tangles (p = 0.001) and the volume of amyloid plaques (p = 0.001), as well as degenerated oligodendrocytes (p =0.003) and phagocytic microglia (p = 0.039). Of the correlations, the strong and positive correlation between the numbers of normal pyramidal and granule neurons in both groups and the strong and positive correlation between the number of granule neurons affected by ptau and phagocytic microglia in the control group stand out. There was also a strong and negative correlation between the number of senescent oligodendrocytes and the volume of neurofibrillary tangles in the exercise group and a strong and negative correlation between the number of senescent oligodendrocytes and the volume of senile plaques in the control group. Conclusions: These findings demonstrate the neuroprotective effect exerted by moderateintensity physical activity regarding agingrelated morphophysiological degeneration of the hippocampus. The integrated observation of the main markers of neurodegeneration, iron accumulation and microglial activity provides a general overview of the behavior of the hippocampus in response to the intervention performed.
Descrição
Citação
ROCHA, Paulo Ricardo. Estudo das alterações morfofisiológicas no hipocampo de ratos idosos submetidos a um programa de exercício físico aeróbico. 2024. 90 f. Dissertaçõa (Mestado em Neurologia - Neurociências) - Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP). São Paulo. 2024.