A GAD inhibitor; reduces GAD activity by 60% when administered at a dose of 39.8 μmol/g per hour ex vivo in mouse brain preparations; i.p. administration (1.2 mmol/kg) induces convulsions and decreases GABA concentration throughout the cerebellum, pons, medulla, striatum, cortex, and hippocampus in mice; chronic administration (3.2 μg/0.5 μl per hour for 13 days) increases locomotor activity in an open field test and impairs attention in the 5-choice serial reaction time task (5CSRTT); inhibits GAD in vitro only when used at high concentrations (1-80 mM)