Discovery of a New Class of Potential Multifunctional Atypical Antipsychotic Agents Targeting Dopamine D3 and Serotonin 5-HT1A and 5-HT2A Receptors: Design, Synthesis, and Effects on Behavior

Dopamine D3 antagonism combined with serotonin 5-HT1A and 5-HT2A receptor occupancy may represent a novel paradigm for developing innovative antipsychotics. The unique pharmacological features of 5i are a high affinity for dopamine D3, serotonin 5-HT1A and 5-HT2A receptors, together with a low affinity for dopamine D2 receptors (to minimize extrapyramidal side effects), serotonin 5-HT2C receptors (to reduce the risk of obesity under chronic treatment), and for hERG channels (to reduce incidence of torsade des pointes). Pharmacological and biochemical data, including specific c-fos expression in mesocorticolimbic areas, confirmed an atypical antipsychotic profile of 5i in vivo, characterized by the absence of catalepsy at antipsychotic dose.