Aversive taste reactivity: reactivity to quinine predicts aversive reactivity to lithium-paired sucrose solution

The ability of a rat's reactivity to the aversive taste properties of quinine to predict its' reactivity to the aversive taste properties of a lithium-paired sucrose solution were assessed. In phase 1, all rats were intraorally infused with 0.05% quinine solution over a 2-min taste reactivity (TR) test. On the basis of their composite aversive reactions, rats were divided into high reactors (HiQ) and low reactors (LoQ). In phase 2, rats were given three TR conditioning/testing trials in which they received a 2-min intraoral infusion of 0.5 M sucrose solution immediately followed by an IP injection of either 127.2 mg/kg lithium chloride or physiological saline. Among rats conditioned with lithium during phase 2, the phase-1 quinine HiQs displayed more aversive reactions than did the phase-1 quinine LoQs. This suggests that reactivity to the aversive properties of quinine may predict the strength of conditioned palatability shifts to a lithium-paired sucrose solution.