Firing of nucleus accumbens neurons during the consummatory phase of a discriminative stimulus task depends on previous reward predictive cues
Firing of nucleus accumbens neurons during the consummatory phase of a discriminative stimulus task depends on previous reward predictive cues
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DOI：
10.1152/jn.00658.2003
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发表时间：
2004-04-01
影响因子：
2.5
通讯作者：
Fields, HL
中科院分区：
文献类型：
--
作者：
Nicola, SM;Yun, IA;Fields, HL
丘脑核（NAc）在食欲和完成行为中起着重要的作用。为了研究NAc神经元在奖励消费过程中如何编码信息，我们记录了大鼠NAc神经元在执行区分刺激任务时的放电活动。在这项任务中，动物必须对间歇性提示做出操作性反应，以获得奖励容器中提供的蔗糖奖励。未提示的进入容器不被奖励。奖励消费过程中的兴奋和抑制都被观察到，但更多的神经元被抑制而不是兴奋。这些兴奋和抑制从动物进入奖励容器时开始，到动物离开容器时结束。当动物在没有提示的情况下进入奖赏容器时，兴奋和抑制都要小得多，甚至不存在。在一组实验中，我们在一些暗示试验中随机扣留了奖励，否则这些试验会得到奖励。无论是否给予奖励，兴奋和抑制的程度都差不多。这表明奖励的感官刺激并不驱动这些阶段性反应;相反，奖励相关的反应可能是由与奖励相关的条件刺激驱动的，或者它们可能编码有关完成运动活动的信息。另一群NAc神经元在从奖励容器中退出时兴奋。许多这些兴奋持续几十秒后，插座出口，并表现出显着的负相关率无线索的操作性反应。这些发现与NAc神经元对奖赏完成和奖赏寻求行为的贡献一致。
The nucleus accumbens (NAc) plays an important role in both appetitive and consummatory behavior. To examine how NAc neurons encode information during reward consumption, we recorded the firing activity of rat NAc neurons during the performance of a discriminative stimulus task. In this task, the animal must make an operant response to an intermittently presented cue to obtain a sucrose reward delivered in a reward receptacle. Uncued entries to the receptacle were not rewarded. Both excitations and inhibitions during reward consumption were observed, but substantially more neurons were inhibited than excited. These excitations and inhibitions began when the animal entered the reward receptacle and ended when the animal exited the receptacle. Both excitations and inhibitions were much smaller or nonexistent when the animal made uncued entries into the reward receptacle. In one set of experiments, we randomly withheld the reward in some cued trials that would otherwise have been rewarded. Excitations and inhibitions were of similar magnitude whether or not the reward was delivered. This indicates that the sensory stimulus of reward does not drive these phasic responses; instead, the reward-associated responses may be driven by the conditioned stimuli associated with reward, or they may encode information about consummatory motor activity. Another population of NAc neurons was excited on exit from the reward receptacle. Many of these excitations persisted for tens of seconds after the receptacle exit and showed a significant inverse correlation with the rate of uncued operant responding. These findings are consistent with a contribution of NAc neurons to both reward consummatory and reward seeking behavior.