Nematode nicotinic acetylcholine receptor (nAChR)

Nematode nicotinic acetylcholine receptors (nAChRs) are pentameric ligand-gated ion channels belonging to the Cys-loop receptor family, present on nematode nerve and muscle membranes. They mediate fast excitatory neurotransmission in nematodes, controlling muscle contraction and movement. These receptors are the principal pharmacological targets for several classes of anthelmintic drugs (including levamisole, pyrantel, oxantel, and tribendimidine), which cause spastic paralysis of the worms by opening the receptor channel, allowing cation influx, and inducing sustained muscle contraction. Nematode nAChRs are composed of multiple subunit types (such as UNC-38, UNC-29, UNC-63, and ACR-8), and different combinations of these subunits generate pharmacologically distinct receptor subtypes with different drug sensitivities and resistance properties. The diversity and stoichiometry of nAChR subunits underlie both the efficacy of anthelmintics and the emergence of drug resistance, which is a growing problem in the control of parasitic nematodes that infect humans and livestock.

Other names

Nematode nAChRNicotinic acetylcholine-gated ion channel (nematode)Nematode acetylcholine receptorCholinergic receptor (nematode)

Agonists (e.g., levamisole, pyrantel, nicotine, oxantel) open the receptor’s ion channel, causing prolonged depolarization, muscle contraction, and spastic paralysis of the nematode, leading to its death. Antagonists (e.g., derquantel) inhibit receptor activation, blocking neurotransmission.