Non-N-methyl-D-aspartate receptors may mediate the transmission of emetic signals between visceral vagal afferents and the solitary nucleus in dogs.

The effects of the N-methyl-D-aspartate (NMDA) and non-NMDA receptor antagonists MK-801 and NBQX, respectively, on salivary secretion and retching induced by vagal stimulation were studied in decerebrate dogs. Vagal stimulation induced an increase in salivary secretion and fictive retching. Intra-4th ventricular application of vehicle or MK-801 did not change either response, while NBQX completely abolished both responses. These results suggest that non-NMDA receptors mediate both responses in the solitary nucleus.