Type 1 Diabetes and Its Long Duration Effect on Cognitive Functions: An Assessment in Alloxan Induced Diabetic Rats

Abstract

Despite the enormous research in the field of Diabetology, its prevalence and complications are raising. Studies made on diabetic subjects showed deficits in cognition and memory in children suffering from long term diabetes. The relationship between cognitive dysfunction and type-1 diabetes of early onset has not been addressed properly. Hence, this study was made to investigate the effect of different duration diabetes onset on cognitive dysfunction. Using alloxan (200 mg/kg bw) induced diabetic rats learning and memory assessments were made, in addition oxidative stress indices studied. The results indicate that the duration of diabetes has significant contribution in learning and memory deficits, which were irreversible and the activity levels of CAT (P < 0.05), SOD, GST (P < 0.05), and GPx (P < 0.05) showed greater impact of free radical damage on hippocampal circuitry. The atrophic changes observed in hippocampal region corroborates the difficulties in learning and memory, and the degenerative changes were most striking in the cells of CA-1 and CA-3 hippocampal regions which could be linked to deficits in certain cognitive domains, such as memory, information processing speed, executive function, attention and motor speed. It is evident from data that brain tissue is not spared by diabetes and diabetic encephalopathy occurs due to metabolic perturbations by hyperglycaemia, insulin deficiency. The findings of this study strongly advocate that learning ability and memory have a direct relation to the duration of the diabetes. The clinical implication of the study highlights the importance of early diagnosis and treatment of juvenile diabetes induced cognitive deficits among children.