This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Central Nervous system, Subject name: Pharmacology
[{'content': 'Vigabatrin acts by \nSelect and explain. \nA. GABA-Antagonism, B. GABA-Agonism, C. NMDA-Antagonism, D. Carbonic anhydrase activity', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Mechanism of Action: Vigabatrin is an irreversible inhibitor of GABA aminotransferase (GABA-T), the enzyme responsible for the degradation of GABA. It may also inhibit the vesicular GABA transpoer. Vigabatrin produces a sustained increase in the extracellular concentration of GABA in the brain. This leads to some desensitization of synaptic GABA A receptors but prolonged activation of nonsynaptic GABA A receptors that provide tonic inhibition. A decrease in brain glutamine synthetase activity is probably secondary to the increased GABA concentrations. Vigabatrin is useful in the treatment of paial seizures and infantile spasms Reference: Katzung Pharmacology; 13th edition; Chapter 24; Antiseizure drugs', 'role': 'assistant'}]