Alteration of Gaba System and Purkinje Cells in Rat Cerebellum by the Convulsant 3‐mercaptopropionic Acid

The effect of the convulsant, 3‐mercaptopropionic acid (MP) on the content of free amino acids and on the activity of some enzymes related to their metabolism was studied in the rat cerebellum. A decrease in the activity of glutamate decarboxylase (EC 4.1.1.15) and in the level of GABA was found; at the same time, the activity of GABA‐aminotransferase (EC 2.6.1.19) was increased. These changes coincided with a profound alteration of the morphology of the Purkinje cells which was related to the dose of MP. These findings, plus some changes in the content of other free amino acids and the activities of related enzymes, suggest that 3‐mercaptopropionic acid induces in the cerebellum an imbalance among the amino acids involved in the excitation‐inhibition mechanisms.