Glutamate decarboxylase and GABA aminotransferase levels in different regions of rat brain on the onset of Leptazol induced convulsions.

The activities of Glutamate decarboxylase (GAD) and Gamma aminobutyric acid (GABA) were studied in three regions of rat brain in heightened neuronal activity resulting in convulsions by Leptazol. These enzymes were studied in preconvulsive, convulsive and post convulsive phases. The activity of GAD decreases significantly in the preconvulsive phase in all the three regions of brain followed by a significant increase during the convulsive and post convulsive phase in cerebral cortex and cerebellum. The activity of GABA-T decreases maximal during the preconvulsive phase followed by convulsive phase. The activity of this enzyme tended to increase to control values when the postconvulsive phase was reached. Therefore, it is suggested that the concomitant decrease of GAD activity and GABA concentration, is probably an important factor in the onset of convulsions.