Reward-dependent modulation of neuronal activity in the primate dorsal raphe nucleus
Reward-dependent modulation of neuronal activity in the primate dorsal raphe nucleus
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DOI：
10.1523/jneurosci.0021-08.2008
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发表时间：
2008-05-14
影响因子：
5.3
通讯作者：
Hikosaka, Okihide
中科院分区：
文献类型：
--
作者：
Nakamura, Kae;Matsumoto, Masayuki;Hikosaka, Okihide
多巴胺系统被认为在指导基于奖励的行为方面发挥着核心作用。最近的药理学研究表明，另一种单胺类神经递质血清素也参与了奖赏过程。为了阐明5-羟色胺神经元和多巴胺神经元之间的功能关系，我们在中缝背核（DRN）（5-羟色胺的主要来源）和黑质（多巴胺的主要来源）进行了单单位记录，而猴子则进行了眼跳任务，其中目标的位置表明即将到来的奖励的大小。目标发病后，但之前的奖励交付，许多DRN神经元的活动调制紧张的预期奖励大小与大或小的奖励偏好，而假定的多巴胺神经元有阶段性的反应，只喜欢大的奖励。奖励传递后，DRN神经元的活动调制紧张收到的奖励大小与大或小的奖励偏好，而多巴胺神经元的活动没有调制，除非意外逆转后的位置奖励应急。因此，DRN神经元编码预期和接收的奖励，而多巴胺神经元编码预期和接收的奖励之间的差异。这些结果表明，DRN，可能包括5-羟色胺神经元，发出与当前行为相关的奖励值信号。
The dopamine system has been thought to play a central role in guiding behavior based on rewards. Recent pharmacological studies suggest that another monoamine neurotransmitter, serotonin, is also involved in reward processing. To elucidate the functional relationship between serotonin neurons and dopamine neurons, we performed single-unit recording in the dorsal raphe nucleus (DRN), a major source of serotonin, and the substantia nigra pars compacta, a major source of dopamine, while monkeys performed saccade tasks in which the position of the target indicated the size of an upcoming reward. After target onset, but before reward delivery, the activity of many DRN neurons was modulated tonically by the expected reward size with either large- or small-reward preference, whereas putative dopamine neurons had phasic responses and only preferred large rewards. After reward delivery, the activity of DRN neurons was modulated tonically by the received reward size with either large- or small-reward preference, whereas the activity of dopamine neurons was not modulated except after the unexpected reversal of the position-reward contingency. Thus, DRN-neurons encode the expected and received rewards, whereas dopamine neurons encode the difference between the expected and received rewards. These results suggest that the DRN, probably including serotonin neurons, signals the reward value associated with the current behavior.