(S)-MCPG is primarily used in neuroscience research as a selective antagonist for group I and group II metabotropic glutamate receptors (mGluRs). It helps in studying the role of these receptors in synaptic transmission, plasticity, and neurological disorders. Researchers utilize it to investigate conditions like epilepsy, Parkinson's disease, and schizophrenia, as it blocks glutamate-mediated signaling pathways. Additionally, it aids in understanding the mechanisms of learning and memory by modulating glutamatergic activity in the brain. Its application is crucial for developing targeted therapies for neurological and psychiatric diseases.