Receptors and transmission in the brain-gut axis: Potential for novel therapies IV. GABA(B) receptors in the brain-gastroesophageal axis

GABA(B) receptors are inhibitory G protein-coupled receptors that are commo nly associated with presynaptic inhibition of transmitter release in the ce ntral nervous system. In the brain-gastroesophageal axis, a role has recent ly been demonstrated for GABA(B) receptors on extrinsic afferent endings wi thin the stomach and esophagus, where they reduce mechanosensitivity. This action is compounded by inhibition of communication centrally from these af ferents in the brain stem and within central circuits. There is a final per ipheral action on the motor pathway where GABA(B) receptors reduce output o f acetylcholine from vagal preganglionic motoneurons. These potent, multipl e actions of GABA(B) receptors may have therapeutic benefit by reducing the triggering of transient lower esophageal relaxations, which are the major cause of gastroesophageal reflux. An important clinical application is ther efore emerging for this recent discovery.