UNC9994 hydrochloride is a functionally selective, β-arrestin–biased dopamine D 2 receptor ( D 2 R ) agonist that selectively activates β-arrestin recruitment and signaling. UNC9994 hydrochloride shows a binding affinity with a K i of 79 nM for D 2 R . UNC9994 hydrochloride is also an antagonist of G i -regulated cAMP production and partial agonist for D2R/β-arrestin-2 interactions. UNC9994 hydrochloride shows antipsychotic-like activity In Vitro UNC9994 hydrochloride induces D 2 -mediated β-arrestin-2 translocation with an EC 50 s of 6.1 nM and 448 nM in Tango assay and DiscoveRx assay, respectively. UNC9994 hydrochloride is an antagonist at 5HT 2A and 5HT 2B and an agonist at 5HT 2C and 5HT 1A. MCE has not independently confirmed the accuracy of these methods. They are for reference only. In Vivo UNC9994 (2.0 mg/kg; i.p.; once) hydrochloride shows antipsychotic activity that is attenuated in β-arrestin-2 knockout mice . MCE has not independently confirmed the accuracy of these methods. They are for reference only. Animal Model: C57BL/6J wild-type and β-arrestin-2 knockout mice Dosage: 2.0 mg/kg, followed 30 min later with 6 mg/kg phencyclidine (PCP, i.p.) Administration: IP, once Result: Markedly inhibited PCP-induced hyperlocomotion in wild-type mice and the activity was completely abolished in β-arrestin-2 knockout mice. Form:Solid IC50& Target:D 3 Receptor 17 nM (Ki) D 2 Receptor 79 nM (Ki) D 4 Receptor 138 nM (Ki) D 1 Receptor 4000 nM (Ki) 5-HT 2B Receptor 25 nM (Ki) 5-HT 1A Receptor 26 nM (Ki) 5-HT 2A Receptor 140 nM (Ki) 5-HT 2C Receptor 512 nM (Ki)