Nicotinic acetylcholine and P2X receptors in the enteric nervous system

It has been known for sometime that neurotransmission in the gastrointestinal tract is complex and involves multiple transmitters, receptors and intracellular signaling mechanisms. Studies of these diverse mechanisms have focused on GPCRs and slow synaptic transmission. It is now apparent that diversity in neurotransmission in the gut extends to multiple ligand-gated ion channels and fast synaptic transmission. Acetylcholine acting at nAChRs is the predominant fast excitatory synaptic transmitter in the autonomic nervous system. However, myenteric neurons also use noncholinergic mechanisms of fast synaptic transmission. ATP acting at P2X receptors is one noncholinergic fast excitatory synaptic transmitter. Noncholinergic mechanisms of fast excitatory synaptic transmission may provide new targets for drugs that could be useful in the treatment of gastrointestinal motility disorders.