Gastric afferents to the nucleus of the solitary tract in the cat.

Afferent projections of the vagus nerve (X) were investigated following nodose ganglion injections of [3H]leucine or horseradish peroxidase (HRP) and stomach wall injections of HRP. Ganglionic injections demonstrated a projection to the solitary nucleus (SN) including the part designated as the area subpostrema (ASP). A projection to the area postrema was also seen following [3H]leucine injections. Stomach wall injections of HRP labelled fibres and terminals bilaterally in the ASP and more ventral parts of the SN. These results provide the first morphological evidence of gastric afferents of X projecting to an area of the SN previously implicated in gastric functions.