THE CONSEQUENCES OF GUSTATORY NERVE TRANSECTION ON TASTE-GUIDED LICKING OF SUCROSE AND MALTOSE IN THE RAT

Lick responses to sucrose and maltose (0.01-1.0 M) were measured in no ndeprived rats during brief-access taste trials before and after histo logically confirmed gustatory neurotomy. Pronounced decreases in sugar responsiveness occurred after combined section of the chorda tympani (CT) and greater superficial petrosal nerves. The additional section o f the glossopharyngeal nerve (GL) flattened the sucrose concentration- response function. Extirpation of the sublingual and submaxillary sali vary glands also attenuated sugar responsiveness. Section of the CP or GL alone or in combination caused less severe or no decreases in suga r licking. There were signs of licking impairments after some of these neurotomies, but the data suggest that changes in sugar responsivenes s were not solely motor in origin. Thus the 7th nerve is necessary and most likely sufficient for the maintenance of normal unconditioned ap petitive responsiveness to sucrose and maltose.