Bulbar gustatory responses to anterior and to posterior tongue stimulation in the rat

Abstract
Amplitudes of neural responses in the nucleus of the fasciculus solitarius to stimulation of the tongue with quinine hydrochloride were analyzed using the response to NaCl as a reference standard. Three distinguishable areas were observed within the gustatory response zone of the nucleus. One area, responsive only to stimulation of the anterior region of the tongue, was at the anterolateral limit of the active zone. A second area, caudal and medial to the first, responded to both anterior and posterior tongue-region stimulation, the latter region yielding larger responses. Medial to both of the other areas was a third, highly responsive area, which responded only to posterior tongue-region stimulation.