Pimozide enhances the aversiveness of quinine solution.

The taste reactivity test was employed to assess the effect of pimozide pretreatment on rats' hedonic responsiveness to palatable and unpalatable tastants. Pimozide selectively enhanced the aversiveness of unconditionally unpalatable quinine solution (Experiment 1) and produced the greatest enhancement of aversion at the highest concentration of quinine (0.1%) solution tested (Experiment 3). Pimozide also enhanced the aversiveness of a conditionally unpalatable lithium-paired solution, but only when the dose of pimozide was relatively high and the strength of the baseline aversion was relatively low (Experiment 2). These results are discussed in light of the anhedonia and the sensorimotor deficit hypotheses of neuroleptic effects on reinforced responding.