Central Gustatory Lesions: I. Preference and Taste Reactivity Tests

Bilateral electrophysiologically guided lesions were placed in the nucleus of the solitary tract (NST), the parabrachial nucleus (PBN), and the ventral posteromedial thalamic nucleus (VPMpc) of rats, and 15-min intake and taste reactivity (TR) responses elicited by 3 concentrations each of sucrose, NaCI, HCI, and quinine (Q) HCI were subsequently measured. Compared with controls, NST lesions had no significant effects on intake, and rats with PBN lesions consumed significantly more QHCI, sucrose, NaCI, and HCI. Thalamic lesions decreased sucrose intake. Analysis of TR responses showed that the QHCI threshold for aversive responses increased after VPMpc, PBN, and NST lesions. Rats with NST or PBN lesions were unresponsive to increasing sucrose concentration. TR responses elicited by NaCI and HCI were similar across the groups.