S 14506 is an agonist of the serotonin (5-HT) receptor subtype 5-HT_1A.^1,2,3,4It selectively binds 5-HT_1Aover 5-HT_1B, 5-HT_1C, 5-HT₂, and 5-HT₃receptors (K_is = 0.98, 281.8, 31.6, 229, and >1,000 nM, respectively) but also binds the dopamine D₂receptor (K_i= 4.57 nM) in radioligand binding assays.^1,2S 14506 stimulates GTPase activity in HEK293 cell membranes expressing 5-HT_1A-Gα_i1or 5-HT_1A-Gα_o1fusion proteins in a concentration-dependent manner.³It reduces immobility time in the forced swim test in rats with a minimum effective dose (MED) of 0.01 mg/kg.⁴S 14506 (0.0025-0.63 mg/kg) increases punished responding in a pigeon conflict procedure, indicating anxiolytic-like activity.¹

1.Colpaert, F.C., Koek, W., Lehmann, J., et al.S 14506: A novel, potent, high-efficacy 5-HT1A agonist and potential anxiolytic agentDrug Dev. Res.26(1)21-48(1992) 2.Protais, P., Chagraoui, A., Arbaoui, J., et al.Dopamine receptor antagonist properties of S 14506, 8-OH-DPAT, raclopride and clozapine in rodentsEur. J. Pharmacol.271(1)167-177(1994) 3.Milligan, G., Kellett, E., Dacquet, C., et al.S 14506: Novel receptor coupling at 5-HT1A receptorsNeuropharmacology40(3)334-344(2000) 4.Schreiber, R., Brocco, M., Gobert, A., et al.The potent activity of the 5-HT1A receptor agonists, S 14506 and S 14671, in the rat forced swim test is blocked by novel 5-HT1A receptor antagonistsEur. J. Pharmacol.271(2-3)537-541(1994)