Refers to neurons, synapses, or receptors where acetylcholine is used as the neurotransmitter.

For example, cholinergic neurons release acetylcholine as their neurotransmitter.

In cholinergic synapses, acetylcholine is released from the presynaptic neuron, and it acts on acetylcholine receptors in the plasma membrane of the postsynaptic cell.

Cholinergic receptors are those that respond to acetylcholine as the physiological ligand. The two major types are nicotinic and muscarinic cholinergic receptors (may also be referred to as nicotinic and muscarinic acetylcholine receptors).

Cholinergic drugs are compounds that mimic the action of acetylcholine by binding to and activating cholinergic receptors.