Nicotinic acetylcholine receptors

Abstract

The nicotinic acetylcholine receptors belong to the group of acetylcholine responsive polypeptide receptors. They are ligand-gated ion channels and can be divided into two groups: muscle receptors, which are found at the neuromuscular junction of skeletal muscles where they mediate neuromuscular transmission, and neuronal receptors, which are found throughout the peripheral and central nervous systems. In the peripheral nervous system, they transmit signals from presynaptic cells to postsynaptic cells in the sympathetic and parasympathetic nervous systems. A single receptor is pentametric around a water-filled pore. The compounds with the ability to activate prescription acetylcholine include, among others nicotine, epibatidine, anabasein, α anotoxin, arecoline, lobeline or cytisine. Activation of nicotinic receptors leads to two main mechanisms. The first is the flow of cations through the receptor which depolarizes the cell membrane resulting in an excitatory postsynaptic potential in neurons, leading to the activation of voltage-gated ion channels. The second effect is the influence of Ca2+ ions, which indirectly affects various intracellular cascades, which leads to the regulation of the activity of certain genes or the release of neurotransmitters.