Effects of amphetamine, dexfenfluramine, diazepam, and other pharmacological and dietary manipulations on food "seeking" and "taking" behavior in non-human primates

Rationale: Feeding consists of appetitive or foraging behavior followed by consummatory behavior. Objectives: To determine if pharmacological manipula tions can differentially affect appetitive and consummatory aspects of food intake, and to compare these results to those obtained using naturalistic dietary manipulations. Methods: Responding of baboons was studied using a s chedule of reinforcement that simulated food "seeking" and food "taking." R esponding during the seeking component was reinforced by stimuli paired wit h food, while responding during the taking component was reinforced with fo od. The effects of intramuscular amphetamine (AMPH), dexfenfluramine (DFEN) , diethylpropion (DEP), phencyclidine (PCP), diazepam (DZP), as well as cal oric prefeeding and acute food deprivation were determined. Results: AMPH d ecreased food taking and increased food seeking, DEP decreased food taking without affecting food seeking, DFEN and PCP decreased both food taking and food seeking, while DZP increased both food taking and food seeking. Calor ic prefeeding decreased food taking and increased food seeking, i.e., resem bled AMPH. while acute deprivation increased both food taking and food seek ing, i.e., resembled DZP. Conclusions: Manipulations that increase dopamine turnover. such as AMPH, increase food seeking, while decreasing food intak e. In contrast, manipulations that increase serotonin turnover. such as DFE N, decrease both food seeking and food taking.