Evidence for dopamine involvement in reinforcement obtained using a latent extinction paradigm

Abstract

The current experiment utilized a modified latent extinction method to examine the question of whether neuroleptic treatment blunts the reinforcing properties of food. Deprived rats were trained to traverse a runway for food reward and were then injected with haloperidol and given ten reinforced direct placements either into the goal box of the alley or into a novel cage with food present. The animals, while still under the influence of the haloperidol, were then given six standard trials of running down the alley. Animals who received goal box placements showed slower run speeds during the test trials than did the subjects who received placements into a neutral cage. These results suggest that placing the haloperidol treated rats into the baited goalbox resulted in a reduced expectation of reward and are compatible with the "anhedonia" theory of neuroleptic action.