Fig. 3.
Gastrointestinal (GI) vagal afferent projections to the hindbrain and the divergence of the pathways for nausea and vomiting. Neurotransmitters that play a role in signaling from vagal afferents to hindbrain sites are indicated; and, presynaptic 5-HT3 receptors, located on vagal afferents potentially modulate these GI inputs.