Nicotine acts as a potent agonist at neuronal nicotinic acetylcholine receptors (nAChRs), particularly in the central nervous system, which modulates neurotransmitter release and neuronal excitability. In the context of cluster headache treatment, nicotine is believed to interrupt pain signaling pathways and reduce inflammatory responses through its sympathomimetic and vasoconstrictive properties, potentially providing rapid abortive or preventive effects.