An antagonist of NR2B subunit-containing NDMA receptors (Kd = 4.2 nM); selective for NR1/NR2B-containing NMDA receptors over NR1, NR2A, and NR2B subunits alone and NR1/NR2A receptors in HEK293 cell homogenates; suppresses mechanical hyperalgesia following carrageenan challenge in rats (30 mg/kg, s.c.); inhibits licking behavior in rats induced by capsaicin and PMA (ED50s = 7.5 and 5.7 mg/kg, respectively); reverses haloperidol-induced catalepsy in rats (ED50 = 0.4 mg/kg); temporarily improves parkinsonian symptoms in an MPTP model of Parkinson's disease in rhesus monkeys