MPEP is primarily used in neuroscience research as a selective antagonist for the metabotropic glutamate receptor subtype 5 (mGluR5). It is widely applied in studies investigating the role of mGluR5 in various neurological and psychiatric disorders, such as anxiety, depression, schizophrenia, and Parkinson's disease. By blocking mGluR5, MPEP helps researchers understand the receptor's function in synaptic plasticity, learning, and memory processes. Additionally, it is utilized in preclinical models to explore potential therapeutic strategies for conditions linked to glutamate dysregulation. Its application has also extended to studying pain mechanisms and addiction, providing insights into the development of novel pharmacological treatments.