A 5-HT3 receptor agonist; selectively binds 5-HT3 receptors (IC50 = 2.8 nM) over 5-HT1A, 5-HT1B, 5-HT1D, 5-HT2, and 5-HT4 receptors (IC50s = >1,000 nM for all); induces contractions in isolated guinea pig ileum at 20 µM; intrastriatal administration induces contralateral turning behavior in mice at 1 UG/animal; reduces immobility time in the forced swim test in rats (ED50 = 7.6 mg/kg); reduces the number of escape failures in a rat model of learned helplessness and the duration of fighting in a mouse model of isolation-induced aggression