High affinity, selective blocker of glial glutamate transporters EAAT1 and EAAT2 (IC50 values are 17, 22 and 300 nM for EAAT2, EAAT1 and EAAT3 respectively). Displays no activity on a wide range of neurotransmitter receptors and transporters. Induces convulsions following i.c.v. administration in mice.