Activation of Dorsal Raphe Serotonin Neurons Underlies Waiting for Delayed Rewards
Activation of Dorsal Raphe Serotonin Neurons Underlies Waiting for Delayed Rewards
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DOI：
10.1523/jneurosci.3714-10.2011
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发表时间：
2011-01-12
影响因子：
5.3
通讯作者：
Doya, Kenji
中科院分区：
文献类型：
--
作者：
Miyazaki, Katsuhiko;Miyazaki, Kayoko W.;Doya, Kenji
能量系统在脉冲行为的控制中起着关键的作用。前脑5-羟色胺耗竭导致过早的行动和陡峭的折扣延迟奖励。然而，没有直接证据表明5-羟色胺神经元的活动与延迟奖励的行为有关。在这里，我们表明，5-羟色胺神经元增加其紧张性放电，而大鼠等待食物和水的奖励和条件强化音。在延迟期内，奖励的强直放电率明显高于音调，因为大鼠不能等待那么长时间。当延迟延长时，紧张性放电持续到奖赏或音调传递。当大鼠因为长时间的延迟或奖励遗漏而放弃等待时，5-羟色胺神经元的放电在从奖励位点退出之前下降。5-羟色胺神经元没有表现出显着的反应时，预期的奖励被省略，这是预测的理论，5-羟色胺信号负奖励预测错误。这些结果表明，增加的5-羟色胺神经元放电促进了大鼠在即将到来的奖励的前景中的等待行为，并且更高的5-羟色胺激活使等待时间更长。
The serotonergic system plays a key role in the control of impulsive behaviors. Forebrain serotonin depletion leads to premature actions and steepens discounting of delayed rewards. However, there has been no direct evidence for serotonin neuron activity in relation to actions for delayed rewards. Here we show that serotonin neurons increase their tonic firing while rats wait for food and water rewards and conditioned reinforcement tones. The rate of tonic firing during the delay period was significantly higher for rewards than for tones, for which rats could not wait as long. When the delay was extended, tonic firing persisted until reward or tone delivery. When rats gave up waiting because of extended delay or reward omission, serotonin neuron firing dropped preceding the exit from reward sites. Serotonin neurons did not show significant response when an expected reward was omitted, which was predicted by the theory that serotonin signals negative reward prediction errors. These results suggest that increased serotonin neuron firing facilitates a rat's waiting behavior in prospect of forthcoming rewards and that higher serotonin activation enables longer waiting.