Used in research to study cholinergic systems in the nervous system, particularly in synaptic transmission. Commonly applied in electrophysiology experiments to activate acetylcholine receptors on neurons and muscle cells. Helps in understanding neuromuscular junction function and neurotransmission mechanisms. Also used in ophthalmic preparations during cataract surgery to induce rapid miosis (pupil constriction). Serves as a pharmacological tool to investigate diseases related to acetylcholine signaling, such as Alzheimer's disease, myasthenia gravis, and Parkinson's disease.