PFI-90 is primarily used in research settings as a potent and selective inhibitor of phosphodiesterase 10A (PDE10A). It is valuable in studying the role of PDE10A in neurological and psychiatric disorders, such as schizophrenia, Huntington's disease, and Parkinson's disease. By inhibiting PDE10A, PFI-90 helps researchers understand the enzyme's function in regulating cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) signaling pathways, which are critical for brain function. This compound is also utilized in preclinical studies to explore potential therapeutic strategies targeting PDE10A for treating these disorders. Its selectivity makes it a useful tool for distinguishing PDE10A's effects from other phosphodiesterases in cellular and animal models.