SINGLE MICROINJECTION OF L-GLUTAMATE INDUCES OXIDATIVE STRESS IN DISCRETE REGIONS OF RAT-BRAIN

Glutamate (Glu) is a major excitatory aminoacid neurotransmitter in th e mammalian brain. Under Certain Circumstances Glu can also exert toxi c effects on neuronal Cells. To unravel the biochemical mechanisms of Glu-induced acute neuronal injury, Glu 1 mu mol/1 mu l was microinject ed into cerebral Cortex, striatum and hippocampus of adult rats and ox idative stress and antioxidant parameters were evaluated. The results show that the rate of lipid peroxidation was significantly increased i n the above brain regions following Glu administration suggesting neur onal membrane damage and also the total and free sulfhydryl groups wer e significantly depleted, indicating altered red-ox status of the cell s. There was also alteration in the activity of antioxidant enzyme cat alase in cerebral cortex. Some of the above Glu-induced effects were r eversed or modified by NMDA receptor antagonist MK-801.