在巴甫洛夫条件反射过程中伏隔核核心区域的实时多巴胺流出

Real-time dopamine efflux in the nucleus accumbens core during Pavlovian conditioning.

作者信息

Sunsay Ceyhun, Rebec George V

机构信息

Department of Psychological and Brain Sciences, Indiana University, Bloomington 47405-7007, USA.

出版信息

Behav Neurosci. 2008 Apr;122(2):358-67. doi: 10.1037/0735-7044.122.2.358.

To assess the role of dopamine input to the nucleus accumbens core in anticipatory learning, fast-scan cyclic voltammetry was combined with appetitive Pavlovian conditioning. One group of rats (Paired) received 16 tone-food pairings for at least four daily sessions while the control group (Unpaired) received the same number of unpaired tone and food presentations. Both groups showed transient dopamine responses during food presentation throughout training, confirming dopamine involvement in reward processing. Only the Paired Group, however, showed consistently timed dopamine transients during the 10-s tone presentation. Transients first appeared near the end of the tone period as each animal acquired the tone-food association and then occurred progressively sooner on subsequent sessions. Later sessions also revealed a consistently timed dopamine response soon after food delivery in Paired animals. Collectively, these results implicate phasic dopamine release in the acquisition of Pavlovian learning and also suggest an early dopamine response to the unconditioned stimulus as training continues.

为了评估伏隔核核心区多巴胺输入在预期学习中的作用，将快速扫描循环伏安法与经典性条件反射相结合。一组大鼠（配对组）接受16次音调-食物配对，每天至少进行4次训练，而对照组（非配对组）接受相同数量的未配对的音调和食物呈现。在整个训练过程中，两组大鼠在食物呈现时均表现出短暂的多巴胺反应，证实多巴胺参与奖赏处理。然而，只有配对组在10秒的音调呈现期间表现出持续定时的多巴胺瞬变。随着每只动物建立起音调-食物关联，瞬变首先出现在音调期接近尾声时，随后在后续训练中出现得越来越早。后期训练还显示，配对组动物在进食后不久也会出现持续定时的多巴胺反应。总体而言，这些结果表明，阶段性多巴胺释放参与了经典条件反射学习的获得，并且还表明随着训练的继续，多巴胺对无条件刺激会产生早期反应。