EFFECTS OF CHRONIC LOW DOSE MONOSODIUN GLUAMATE ON THE CEREBRAL CORTEX IN FEMALE ADULT WISAR RATS

ABSTRACT This study investigates the histopathological effects of chronic low-dose monosodium glutamate (MSG) administration on the cerebral cortex of adult female Wistar rats, addressing a critical gap in understanding the neurotoxic potential of MSG at doses reflective of typical human dietary exposure. Fifteen rats were divided into three groups: a control group receiving 0.9% normal saline, a low-dose group receiving 300 mg/kg MSG, and a chronic low-dose group receiving 1000 mg/kg MSG, administered orally for 60 days. The cerebral cortex was examined using Hematoxylin and Eosin (H&E) and Cresyl Violet staining at 40x and 100x magnifications to assess neuronal morphology, glial responses, and cortical architecture. Results revealed dosedependent neurotoxic effects, with the control group displaying normal histology, including intact neuronal cell bodies and cortical layers. The low-dose group (300 mg/kg) exhibited mild neuronal shrinkage, reduced neuronal density, and early gliosis, particularly in layers II-III, while the chronic low-dose group (1000 mg/kg) showed pronounced neuronal degeneration, pyknotic nuclei, vacuolation, and significant gliosis, indicating severe excitotoxic damage. Additionally, MSG-treated rats demonstrated increased brain and body weights, with the 1000 mg/kg group showing the most significant changes, likely due to reactive gliosis and metabolic disturbances. These findings align with previous studies on MSG-induced neurotoxicity but uniquely highlight subtle, progressive damage at low doses. The study underscores the need for caution in dietary MSG consumption, suggesting potential risks to brain health even at levels commonly encountered in human diets. These results advocate for further research into MSG’s long-term effects on cognition and behavior and inform public health policies regarding its dietary regulation. x