The Role of Dopamine in the Prelimbic Cortex and the Dorsomedial Striatum in Instrumental Conditioning
The Role of Dopamine in the Prelimbic Cortex and the Dorsomedial Striatum in Instrumental Conditioning
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DOI：
10.1093/cercor/bhp151
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发表时间：
2010-04-01
期刊：
影响因子：
3.7
通讯作者：
Hauber, Wolfgang
中科院分区：
文献类型：
--
作者：
Lex, Bjoern;Hauber, Wolfgang
前额叶皮层的边缘前区和背内侧纹状体的后亚区是支持工具性学习的皮质纹状体回路的组成部分。在这里，我们研究了多巴胺（DA）信号传达到PL和pDMS是否是工具学习的关键。将6-羟基多巴胺或载体输注到PL和pDMS中的大鼠训练为按压2个杠杆，用于食物颗粒或蔗糖溶液。此后，我们测试了动物是否对1）使用特定饱腹感程序的2种结果中的1种的选择性退化敏感，以及2）对控制工具行为的2种偶然事件中的1种的选择性退化敏感。PL DA耗竭的大鼠显示杠杆按压率降低，但似乎对结果贬值和应急降解敏感。因此，PL DA似乎调节杠杆按压，但不支持工具性条件反射。与此相反，大鼠与pDMS DA耗尽有完整的反应率和敏感的选择性结果贬值，但是，他们表现出降低的敏感性，应急降解。因此，pDMS DA信号似乎不参与维持杠杆按压，而是通过支持检测动作及其后果之间的因果关系来促进工具性条件反射。
The prelimbic (PL) region of the prefrontal cortex and the posterior subregion of the dorsomedial striatum (pDMS) are components of a corticostriatal circuit subserving instrumental learning. Here, we examined whether dopamine (DA) signals conveyed to the PL and pDMS are critical for instrumental learning. Rats with 6-hydroxydopamine or vehicle infusion into the PL and pDMS were trained to press 2 levers, either for food pellets or a sucrose solution. Thereafter, we tested whether the animals were sensitive 1) to a selective degradation of 1 of 2 outcomes using a specific satiety procedure and 2) to a selective degradation of 1 of 2 contingencies controlling instrumental behavior. Rats with PL DA depletion displayed a reduced rate of lever presses but appeared to be sensitive to outcome devaluation and contingency degradation. Thus, PL DA seems to modulate lever pressing but does not support instrumental conditioning. In contrast, rats with pDMS DA depletion had intact response rates and were sensitive to selective outcome devaluation; however, they showed a reduced sensitivity to contingency degradation. Therefore, pDMS DA signaling seems not to be involved in maintaining lever pressing but instead contributes to instrumental conditioning by supporting the detection of causal relationships between an action and its consequences.