Cone snails comprise 500 species of venomous molluscs, which have evolved the ability to generate multiple toxins with varied and often exquisite selectivity. One class, the a-conotoxins, is proving to be a powerful tool for the differentiation of nicotinic acetylcholine receptors (nAChRs). These comprise a large family of complex subtypes, whose significance in physiological functions and pathological conditions is increasingly becoming apparent. After a short introduction into the structure and diversity of nAChRs, this overview summarizes the identification and characterization ofa-conotoxins with selectivity for neur