Gustatory functions of the nucleus tractus solitarius in the rabbit.

Multiunit analysis revealed a rostral region of NTS containing cells responsive to taste stimulation of rostral tongue. Using representative stimuli for the 4 basic types of taste, maximal incidence and magnitude of response was found to NaCl, followed by HCl, sucrose and QHCl. Further analysis of temporal patterns of response to the tastants revealed differences among stimuli in latency and time course. A principal components analysis indicated that time course, apart from magnitude of response, could contribute to neural differentiation of tastants. Information was also derived on neural intensity functions for these basic types of tastants. Additional observations with sodium saccharin revealed minimal neuronal responsivity despite reported evidence of behavioral preference for this tastant by rabbits.