Investigation of the Effects of Monosodium Glutamate on Cortex and Hippocampus in Normal Aging Rats

Objective: This study aims to investigate the expressions of the dopamine transporter (DAT), dopamine receptor 1 (D1), and dopamine receptor 2 (D2) in the cortex and hippocampus tissues of monosodium glutamate (MSG)-administered aged rats. Method: Neuronal degeneration and dilated blood vessels in the hippocampus and cortex of the experimental groups’ brain tissues were evaluated by histopathological analysis. Immunoreactivity of DAT, D1, and D2 was determined by immunohistochemical analysis. Results: Neuronal degeneration in the cortex was significantly higher in aged rats than in the control group. DAT, D1, and D2 reactivities in the hippocampus and cortex of aged rats were significantly increased compared to those in the control group. Conclusion: No significant difference was found between the aged rats and the control group in terms of dilated blood vessels in the hippocampus and cortex. The increased DAT, D1, and D2 expressions in the hippocampus and cortex tissues of aged rats in our study may highlight the importance of dopamine. Our data may contribute to understanding age-related impairments in motor and cognitive functions through dopaminergic pathways.