Used as a selective antagonist for NMDA (N-methyl-D-aspartate) receptors in neuroscience research. It helps block excitatory neurotransmission to study synaptic plasticity, learning, and memory mechanisms. Commonly applied in electrophysiological experiments and animal models to investigate neurodegenerative diseases, epilepsy, and neuropathic pain. Its lithium salt form improves solubility and stability in aqueous solutions, making it suitable for in vitro and in vivo studies.