A GABAB receptor antagonist (Ki = 4.5 nM); increases electrical stimulation-induced GABA release in the absence and presence of (–)-baclofen, as well as glutamate release in the presence of (–)-baclofen, in rat cerebral cortex slices (EC50s = 8.3, 25, and 14 nM, respectively); inhibits (–)-baclofen-induced postsynaptic hyperpolarization of evoked IPSPs and fEPSPs in rat CA1 hippocampal slices at 1 µM; increases swimming time, but does not decrease immobility time, in the forced swim test in rats at 3 or 10 mg/kg; reverses age-induced impairments in olfactory discrimination learning in rats at 0.01 and 0.1 mg/kg; increases seizure intensity in a mouse model of PTZ kindling-induced epilepsy