Dopamine and preparatory behavior: III. Effects of metoclopramide and thioridazine.

The effects of metoclopramide and thioridazine on feeding behaviors of male hooded rats were investigated in 2 experiments. Metoclopramide (2.5-7.5 mg/kg) attenuated conditioned preparatory responses to a conditional stimulus signaling delivery of a meal. However, consummatory responses were affected only by the highest dose. Similar effects had previously been observed following administration of pimozide (Blackburn, Phillips, & Fibiger, 1987). Thioridazine (10-30 mg/kg) had no significant effect on any measure of feeding behavior. The different effects of the 2 drugs may be related to their preferential actions at dopamine terminals in anatomically distinct regions of the forebrain.