Introduction: Hippocampus is one of the most sensitive region of central nervous system to metabolic disorders. Structurally
it is composed of cornu ammonis and dentate gyrus. CA3 and CA1 play critical role in cognitive performance and psychosis.
Aim: The aim of this study was to study the effects of diabetes mellitus on bilateral CA3 and CA1.
Materials and Methods: Male adult wistar rats were randomly into two groups as diabetic and control. Diabetes mellitus was
induced by a single intraperitoneal (IP) injection of STZ at a dose of 60 mg/kg. The control animals only received saline. Two
months after uncontrolled diabetes, the animals were anesthetized. The harvested whole brains were stained with cresyl violet.
Results: The number of degenerated neurons in right side CA3 (600±25) showed significant level of difference with left CA3
(0) (P<0.001). The count of degenerated neurons in right side CA1 (90±5) showed significant difference with left side CA1
region (5±2) (P<0.001).
Conclusion: Our study showed that experimental diabetes mellitus type 1 leads to unilateral neurodegeneration in pyramidal
layer of CA3 and CA1 regions of right hippocampus.