NMDAR1 mRNA expression in the brainstem circuit controlling esophageal peristalsis.

We investigated the expression of NMDA receptors within the brainstem circuit controlling esophageal swallowing using transneuronal viral labeling and in situ hybridization. Neurons of the central subnucleus of the nucleus solitary tract (NTScen) are interneurons linking vagal afferents with esophageal motoneurons in the compact formation of the nucleus ambiguus (NAc). Following injections of Pseudorabies virus (PRV) into rat esophagus and incubation with NMDAR1 cRNA, neurons infected with PRV localized to the NAc and NTScen expressed NMDAR1 mRNA.