Wickens Jeffery R, Horvitz Jon C, Costa Rui M, Killcross Simon
Okinawa Institute of Science and Technology, Okinawa 904-2234, Japan.
J Neurosci. 2007 Aug 1;27(31):8181-3. doi: 10.1523/JNEUROSCI.1671-07.2007.
Recent studies suggest new ways to interpret dopaminergic actions in goal-directed performance and habitual responding. In the early stages of learning dopamine plays an essential role, but with extended training dopamine appears to play a decreasing role in response expression. Experimental manipulation of dopamine levels alters the correlation of cortical and striatal neural activity in behaving animals, and these dopamine-dependent changes in corticostriatal correlations may be reflected in changes in action selection in the basal ganglia. Consistent with this hypothesis, changes in dopamine signaling brought about by sensitization with amphetamine mimic the transition from goal-directed to habit-based instrumental performance. At the cellular level, dopamine-dependent synaptic plasticity may be important initially, and subsequently lead to more persistent changes that no longer require dopamine. The locus of these actions within the cortical and corticostriatal circuitry is a focus on ongoing research.
近期研究提出了新方法来解释多巴胺能在目标导向行为和习惯性反应中的作用。在学习的早期阶段，多巴胺起着至关重要的作用，但随着训练的延长，多巴胺在反应表达中似乎发挥着越来越小的作用。对多巴胺水平的实验性操控会改变行为动物中皮质和纹状体神经活动的相关性，而这些皮质纹状体相关性中依赖多巴胺的变化可能会反映在基底神经节动作选择的变化中。与该假设一致，由苯丙胺致敏引起的多巴胺信号变化模拟了从目标导向到基于习惯的工具性表现的转变。在细胞水平上，依赖多巴胺的突触可塑性最初可能很重要，随后会导致更持久的变化，而这些变化不再需要多巴胺。这些作用在皮质和皮质纹状体回路中的位点是当前研究的重点。
