Learning Objective 1: To know the morphological hippocampal changes induced by diabetes mellitus in an experimental model.
Learning Objective 2: To learn about cellular alterations occurring in the brain during diabetes mellitus.
Methods: Three weeks old Wistar male rats were randomly distributed in two groups: diabetics and control. Experimental DM was streptozotocine-induced. Weight and blood glucose were tested prior and 24 h following diabetes induction. Animals were considered diabetic when blood glucose was >250 mg/dl. Under pentobarbital (60 mg/kg) anesthesia brain tissue was fixed by 10% formaldehyde intracardiac perfusion. 3 mm-thick hippocampal slices were obtained and hematoxylin-eosin stained to be evaluated under 40 and 100X objectives, dry and oil immersion respectively. Image-Pro 6.1 digital images were saved for analysis.
Results: Qualitative modifications including axonal disruption, plasmatic membrane disorganization, cell body morphology alterations, dendrites shortening, as well as interneuronal spatial-relation changes were documented. Quantitatively, reduced cellularity was observed in CA2 and CA3, while an increased number of neural cells in CA1 and dentate gyrus was seen. Also a 12% reduction in the CA2 pyramidal cell bodies was found. Conclusion: The cell and hippocampal tissue modifications observed under diabetic conditions are important, and could be responsible for the deteriorated brain superior functions observed in diabetic patients, particularly for memory loss and learning disability.