Spiperone hydrochloride is primarily used in scientific research as a potent antagonist for dopamine D2 and serotonin 5-HT2A receptors. It serves as a valuable tool in neuropharmacological studies to investigate the role of these receptors in behavior, cognition, and psychiatric disorders such as schizophrenia. Due to its high affinity for dopamine receptors, it is also used in receptor binding assays to quantify receptor density and drug interactions. Additionally, radiolabeled forms of spiperone hydrochloride are employed in imaging studies, including positron emission tomography (PET), allowing researchers to visualize and measure dopamine receptor distribution and occupancy in the brain. Its application extends to studying drug efficacy and mechanisms of antipsychotic medications.