Dynamic Fluctuations in Dopamine Efflux in the Prefrontal Cortex and Nucleus Accumbens during Risk-Based Decision Making
Dynamic Fluctuations in Dopamine Efflux in the Prefrontal Cortex and Nucleus Accumbens during Risk-Based Decision Making
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基于风险的决策过程中前额皮质和伏核多巴胺流出的动态波动
DOI：
10.1523/jneurosci.3807-12.2012
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
S. Floresco
中科院分区：
文献类型：
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作者：
Jennifer R St Onge;Soyon Ahn;A. Phillips;S. Floresco
中皮质边缘多巴胺（DA）与风险和回报的成本/收益决策有关。前额叶皮层（PFC）和丘脑核（NAc）是两个以不同方式参与决策的DA终末区域。然而，如何紧张性DA水平的波动可能与决策的不同方面仍有待确定。本研究测量DA流出的PFC和NAC微透析训练有素的大鼠执行概率折扣任务。选择一个小的/特定的选项总是会产生一个颗粒，而另一个大的/有风险的选项会产生四个颗粒，在四个试验区组中，概率会减少（100-12.5%）或增加（12.5-100%）。轭奖励组也被包括在内，以控制奖励交付。PFC DA流出在决策过程中减少或增加了一个会话，对应于大/风险奖励概率的变化。类似的配置文件中观察到的轭奖励大鼠，这表明PFC DA的波动反映了奖励收到的相对速率的变化。NAc DA流出也显示出减少/增加的趋势，在这两个任务的会议。然而，DA外排更高的自由与强迫选择试验的决策过程中，在更大的奖励不确定性。此外，NAc DA的变化密切跟踪选择偏差的变化。这些数据揭示了PFC和NAc DA传输与基于风险的决策的不同方面相关的动态和可分离的波动。PFC DA可以信号的变化，奖励的可用性，促进修改的选择偏差，而NAC DA编码有关奖励率，不确定性和选择的综合信号，反映决策政策的实施。
Mesocorticolimbic dopamine (DA) has been implicated in cost/benefit decision making about risks and rewards. The prefrontal cortex (PFC) and nucleus accumbens (NAc) are two DA terminal regions that contribute to decision making in distinct manners. However, how fluctuations of tonic DA levels may relate to different aspects of decision making remains to be determined. The present study measured DA efflux in the PFC and NAc with microdialysis in well trained rats performing a probabilistic discounting task. Selection of a small/certain option always delivered one pellet, whereas another, large/risky option yielded four pellets, with probabilities that decreased (100–12.5%) or increased (12.5–100%) across four blocks of trials. Yoked-reward groups were also included to control for reward delivery. PFC DA efflux during decision making decreased or increased over a session, corresponding to changes in large/risky reward probabilities. Similar profiles were observed from yoked-rewarded rats, suggesting that fluctuations in PFC DA reflect changes in the relative rate of reward received. NAc DA efflux also showed decreasing/increasing trends over the session during both tasks. However, DA efflux was higher during decision making on free- versus forced-choice trials and during periods of greater reward uncertainty. Moreover, changes in NAc DA closely tracked shifts in choice biases. These data reveal dynamic and dissociable fluctuations in PFC and NAc DA transmission associated with different aspects of risk-based decision making. PFC DA may signal changes in reward availability that facilitates modification of choice biases, whereas NAc DA encodes integrated signals about reward rates, uncertainty, and choice, reflecting implementation of decision policies.