Dopamine levels modulate the updating of tastant values
Dopamine levels modulate the updating of tastant values
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DOI：
10.1111/j.1601-183x.2006.00257.x
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发表时间：
2007-06-01
影响因子：
2.5
通讯作者：
Simon, S. A.
中科院分区：
文献类型：
--
作者：
Costa, R. M.;Gutierrez, R.;Simon, S. A.
为了生存，动物必须不断更新它们遇到的刺激的内在价值；这个过程被称为激励性学习。虽然已经有许多研究调查了多巴胺是否对奖赏是必要的，或者是刺激和行为与奖赏之间的联系，但关于多巴胺在刺激本身的内在价值更新中所起的作用却知之甚少。我们使用单瓶强制选择任务来研究多巴胺在了解品尝者价值方面的作用。我们发现，多巴胺转运蛋白基因敲除小鼠(DAT-KO)具有结构性的高多巴胺水平，与它们的野生型小鼠相比，它们对享乐积极的味道(蔗糖400 mM)产生了更积极的偏见。此外，与野生型小鼠相比，DAT-KO小鼠对享乐性负面口味(奎宁盐酸盐10 mM)的负面偏见较小。重要的是，这些效应随着训练而发展，因为在训练开始时，DAT-KO和野生型小鼠对蔗糖和奎宁表现出类似的偏见。这些数据表明，多巴胺水平可以调节味觉价值的更新，这一发现对理解特定于感官的动机和寻求奖励具有重要意义。
To survive, animals must constantly update the internal value of stimuli they encounter; a process referred to as incentive learning. Although there have been many studies investigating whether dopamine is necessary for reward, or for the association between stimuli and actions with rewards, less is known about the role of dopamine in the updating of the internal value of stimuli per se. We used a single-bottle forced-choice task to investigate the role of dopamine in learning the value of tastants. We show that dopamine transporter knock-out mice (DAT-KO), which have constitutively elevated dopamine levels, develop a more positive bias towards a hedonically positive tastant (sucrose 400 mM) than their wild-type littermates. Furthermore, when compared to wild-type littermates, DAT-KO mice develop a less negative bias towards a hedonically negative tastant (quinine HCl 10 mM). Importantly, these effects develop with training, because at the onset of training DAT-KO and wild-type mice display similar biases towards sucrose and quinine. These data suggest that dopamine levels can modulate the updating of tastant values, a finding with implications for understanding sensory-specific motivation and reward seeking.