Puryear Corey B, Kim Min Jung, Mizumori Sheri J Y
Picower Institute for Learning and Memory, MassachusettsInstitute of Technology, Cambridge, Massachusetts, USA.
Behav Neurosci. 2010 Apr;124(2):234-47. doi: 10.1037/a0018865.
As one of the two main sources of brain dopamine, the ventral tegmental area (VTA) is important for several complex functions, including motivation, reward prediction, and contextual learning. Although many studies have identified the potential neural substrate of VTA dopaminergic activity in reward prediction functions during Pavlovian and operant conditioning tasks, less is understood about the role of VTA neuronal activity in motivated behaviors and more naturalistic forms of context-dependent learning. Therefore, VTA neural activity was recorded as rats performed a spatial memory task under varying contextual conditions. In addition to reward- and reward predicting cue-related firing commonly observed during conditioning tasks, the activity of a large proportion of VTA neurons was also related to the velocity and/or acceleration of the animal's movement. It is important to note that movement-related activity was strongest when rats displayed more motivation to obtain reward. Furthermore, many cells displayed a dual code of movement- and reward-related activity. These two modes of firing, however, were differentially regulated by context information, suggesting that movement- and reward-related firing are two independently regulated modes of VTA neuronal activity and may serve separate functions.
作为大脑多巴胺的两个主要来源之一，腹侧被盖区（VTA）对多种复杂功能至关重要，包括动机、奖励预测和情境学习。尽管许多研究已经确定了在经典条件反射和操作性条件反射任务中，VTA多巴胺能活动在奖励预测功能中的潜在神经基础，但对于VTA神经元活动在动机行为和更自然形式的情境依赖学习中的作用了解较少。因此，在大鼠于不同情境条件下执行空间记忆任务时，记录了VTA神经活动。除了在条件反射任务中常见的与奖励和奖励预测线索相关的放电外，很大一部分VTA神经元的活动还与动物运动的速度和/或加速度有关。需要注意的是，当大鼠表现出更强的获取奖励动机时，与运动相关的活动最为强烈。此外，许多细胞表现出与运动和奖励相关活动的双重编码。然而，这两种放电模式受情境信息的调节方式不同，表明与运动和奖励相关的放电是VTA神经元活动的两种独立调节模式，可能具有不同的功能。
