Nicotinic acetylcholine receptor
Nicotinic acetylcholine receptors, or nAChRs, are cholinergic receptors that form ligand-gated ion channel
Ligand-gated ion channel
Ligand-gated ion channels are one type of ionotropic receptor or channel-linked receptor. They are a group of transmembrane ion channels that are opened or closed in response to the binding of a chemical messenger , such as a neurotransmitter.The binding site of endogenous ligands on LGICs...

s in the plasma membranes of certain neurons and on the postsynaptic side of the neuromuscular junction
Neuromuscular junction
A neuromuscular junction is the synapse or junction of the axon terminal of a motor neuron with the motor end plate, the highly-excitable region of muscle fiber plasma membrane responsible for initiation of action potentials across the muscle's surface, ultimately causing the muscle to contract...

 . As ionotropic receptors, nAChRs are directly linked to ion channels and do not use second messengers (as metabotropic receptor
Metabotropic receptor
Metabotropic receptor is a subtype of membrane receptors at the surface or in vesicles of eukaryotic cells.In the nervous system, based on their structural and functional characteristics, neurotransmitter receptors can be classified into two broad categories: metabotropic and ionotropic receptors...

s do).

Like the other type of acetylcholine receptor
Acetylcholine receptor
An acetylcholine receptor is an integral membrane protein that responds to the binding of acetylcholine, a neurotransmitter.-Classification:...

 – the muscarinic acetylcholine receptor
Muscarinic acetylcholine receptor
Muscarinic receptors, or mAChRs, are acetylcholine receptors that form G protein-coupled in the plasma membranes of certain neurons and other cells...

 (mAChR) – the nAChR is triggered by the binding of the neurotransmitter
Neurotransmitters are endogenous chemicals that transmit signals from a neuron to a target cell across a synapse. Neurotransmitters are packaged into synaptic vesicles clustered beneath the membrane on the presynaptic side of a synapse, and are released into the synaptic cleft, where they bind to...

The chemical compound acetylcholine is a neurotransmitter in both the peripheral nervous system and central nervous system in many organisms including humans...