Spatial memory in sedentary and trained diabetic rats: molecular mechanisms.
Hippocampus
; 24(6): 703-11, 2014 Jun.
Article
em En
| MEDLINE
| ID: mdl-24916112
Diabetes mellitus is a chronic disease that has been associated with memory loss, neurological disorders, and Alzheimer's disease. Some studies show the importance of physical exercise to prevent and minimize various neurological disorders. It is believed that the positive effects of exercise on brain functions are mediated by brain insulin and insulin-like growth factor-1 (IGF-1) signaling. In this study, we investigate the role of swimming exercise training on hippocampus proteins related to insulin/IGF-1 signaling pathway in Type 1 diabetic rats and its effects on spatial memory. Wistar rats were divided into four groups namely sedentary control, trained control, sedentary diabetic (SD), and trained diabetic (TD). Diabetes was induced by Alloxan (ALX) (32 mg/kg b.w.). The training program consisted in swimming 5 days/week, 1 h/day, per 6 weeks, supporting an overload corresponding to 90% of the anaerobic threshold. We employed ALX-induced diabetic rats to explore learning and memory abilities using Morris water maze test. At the end of the training period, the rats were sacrificed 48 h after their last exercise bout when blood samples were collected for serum glucose, insulin, and IGF-1 determinations. Hippocampus was extracted to determinate protein expression (IR, IGF-1R, and APP) and phosphorylation (AKT-1, AKT-2, Tau, and ß-amyloide proteins) by Western Blot analysis. All dependent variables were analyzed by two-way analysis of variance with significance level of 5%. Diabetes resulted in hyperglycemia and hypoinsulinemia in both SD and TD groups (P < 0.05); however, in the training-induced group, there was a reduction in blood glucose in TD. The average frequency in finding the platform decreased in SD rats; however, exercise training improved this parameter in TD rats. Aerobic exercise decreased Tau phosphorylation and APP expression, and increased some proteins related to insulin/IGF-1 pathway in hippocampus of diabetic rats. Thus, these molecular adaptations from exercise training might contribute to improved spatial learning and memory in diabetic organisms.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Condicionamento Físico Animal
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Natação
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Fator de Crescimento Insulin-Like I
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Diabetes Mellitus Experimental
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Memória Espacial
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Insulina
Limite:
Animals
Idioma:
En
Revista:
Hippocampus
Assunto da revista:
CEREBRO
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Estados Unidos