Pharmacological manipulations of food protection behavior in rats: evidence for dopaminergic contributions to time perception during a natural behavior.

Operant procedures combined with pharmacological manipulations have implicated a role for the dopaminergic system in the perception and production of temporal intervals. Because studies have suggested that animals use temporal information to organize food protection behavior, the current study investigates whether dopaminergic systems are involved in timing during this natural behavior. The experiment examined the influence of a dopaminergic agonist (amphetamine) and an antagonist (haloperidol) on food protection behavior initiated to avoid theft by a conspecific. Amphetamine increased the time spent dodging and decreased the time spent bracing during the consumption of a hazelnut. On the other hand, haloperidol decreased the time spent dodging while showing no systematic changes in bracing. Topographic and kinematic analyses of rat movement conflicted with motivational, motoric, and social accounts of drug-induced changes in food protection behavior organization. These observations provide evidence that rats use temporal information to organize movements in the natural behavior of protecting food from theft by a conspecific, and this organization is influenced by both a dopaminergic agonist and an antagonist.