α-Conotoxin MII is primarily used in neuroscience research due to its ability to selectively block specific subtypes of nicotinic acetylcholine receptors (nAChRs). It is particularly effective in inhibiting α3β2 nAChRs, making it a valuable tool for studying the role of these receptors in the nervous system. Researchers utilize this peptide to investigate neurotransmitter release, synaptic plasticity, and the mechanisms underlying addiction, especially nicotine dependence. Its high specificity also aids in distinguishing between different nAChR subtypes, contributing to the development of targeted therapies for neurological disorders and pain management.