Used primarily in scientific research as a selective agonist for M1 muscarinic acetylcholine receptors, McN-A 343 helps investigate cholinergic signaling in the central nervous system. It is valuable in studies related to cognitive functions, memory, and neurodegenerative diseases such as Alzheimer's. Due to its ability to differentiate M1 receptor activity from other muscarinic subtypes, it serves as a tool compound in pharmacological assays and receptor characterization. Its application is mostly restricted to in vitro and animal studies, aiding in the development of targeted therapies for neurological and psychiatric disorders.