查看文章

We recently demonstrated that dopamine D1 receptors in the ventral tegmental area (VTA) are involved in intravenous cocaine reward. Here, we investigated whether VTA D1 receptors also are involved in food reward by testing the hypothesis that blockade of dopamine D1 receptors in the VTA attenuates the rewarding effects of food. Eighteen rats, with bilateral cannulae positioned to allow for microinjections in or just dorsal to the VTA, were trained to lever press under a progressive ratio schedule of reinforcement. After stable break points (BPs) were established, the rats received bilateral microinjections of SCH 23390, a D1 receptor antagonist. In Experiment 1, where the reward consisted of 1 food pellet, injections of SCH 23390 (0, 1, 2, or 4 μg/0.5 μl) in the VTA (N = 9) significantly decreased BPs (P < 0.001), while bilateral microinjections dorsal to the VTA (N = 9) did not. In Experiment 2 (N = 6), where the …