Phaclofen is primarily used in neuroscience research as a selective antagonist for GABA_B receptors. It helps in studying the role of these receptors in the central nervous system, particularly in understanding synaptic transmission and neural circuitry. Researchers use it to investigate conditions like anxiety, depression, and epilepsy, as GABA_B receptors are involved in modulating these states. Additionally, it aids in exploring the mechanisms of muscle relaxation and pain modulation, contributing to the development of potential therapeutic strategies. Its application is limited to experimental settings and is not used clinically.