Dopamine in the orbitofrontal cortex regulates operant responding under a progressive ratio of reinforcement in rats
Dopamine in the orbitofrontal cortex regulates operant responding under a progressive ratio of reinforcement in rats
复制标题
DOI：
10.1016/j.neulet.2004.08.002
复制
发表时间：
2004-11-11
影响因子：
2.5
通讯作者：
Koch, M
中科院分区：
文献类型：
--
作者：
Cetin, T;Freudenberg, F;Koch, M
前额叶皮质多巴胺（Prefrontocortical dopamine，DA）在认知功能和行为的调节中起着重要的作用。眶额皮质（OFC）接受来自腹侧被盖区的多巴胺能投射，对于目标导向的食欲行为和奖励价值的神经表征特别重要。在这里，我们研究了DA受体阻滞剂局部注入OFC的影响，在渐进式强化计划下的工具行为。在连续强化训练（杠杆按压酪蛋白颗粒）后，大鼠通过长期留置套管接受DA D1受体拮抗剂SCH 23390（3 μ g/0.5穆尔）、DA D2受体拮抗剂舒必利（3 μ g/0.5穆尔）或磷酸盐缓冲盐水的双侧OFC内输注。输注后立即在时间限制的渐进比例强化方案下对其进行测试（3，6，9，12，. . .在180秒内对1个酪蛋白颗粒进行杠杆按压）。与溶媒输注相比，SCH 23390和舒必利均导致折点显著降低（停止对工具作用增加标准的反应）。食物偏好测试显示，药物对消耗的颗粒量和酪蛋白颗粒优于实验室食物的偏好没有影响。渐进比率任务中断点的左移表明，在工具性努力增加的条件下，将动机转化为食欲行为的机制受到干扰。因此，我们的数据表明，眶额多巴胺是必要的奖励相关的工具性行为。(C)2004爱思唯尔爱尔兰有限公司保留所有权利。
Prefrontocortical dopamine (DA) plays an essential role in the regulation of cognitive functions and behavior. The orbitofrontal cortex (OFC) receives a dopaminergic projection from the ventral tegmental area and is particularly important for goal-directed appetitive behaviors and for the neural representation of reward value. We here examined the effects of DA receptor blockers locally infused into the OFC, on instrumental behavior under a progressive schedule of reinforcement. After continuous reinforcement training (lever pressing for casein pellets) rats received bilateral intra-OFC-infusions of the DA D1-receptor antagonist SCH23390 (3 mug/0.5 mul), the DA D2-receptor antagonist sulpiride (3 mug/0.5 mul), or phosphate buffered saline through chronically indwelling cannulae. Immediately after infusion they were tested under a time-constrained progressive ratio schedule of reinforcement (3, 6, 9, 12, . . . lever presses for 1 casein pellet within 180 s). Both SCH23390 and sulpiride led to a significant reduction of the break point (cessation to respond to the increasing criterion of instrumental effort) compared to vehicle infusions. A food preference test revealed no drug effects on the amount of consumed pellets and on the preference of casein pellets over laboratory chow. Leftward shifts of the break point in progressive ratio tasks indicate a disturbance of the mechanisms that translate motivation into appetitive behavior under conditions of increasing instrumental effort. Therefore, our data indicate that orbitofrontal dopamine is necessary for reward-related instrumental behavior. (C) 2004 Elsevier Ireland Ltd. All rights reserved.