Discriminative cues indicating reward magnitude continue to determine reaction time of rats following lesions of the nucleus accumbens
Discriminative cues indicating reward magnitude continue to determine reaction time of rats following lesions of the nucleus accumbens
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DOI：
10.1111/j.1460-9568.1995.tb01046.x
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发表时间：
1995-12-01
影响因子：
3.4
通讯作者：
Bowman, EM
中科院分区：
文献类型：
--
作者：
Brown, VJ;Bowman, EM
核心的激励动机的作用是公认的，但了解甚少。在这项研究中，我们研究了大鼠的动机行为的一个方面，这可能是由核介导的，即动机信号（奖励的预期值）转化为运动输出（响应奖励）。老鼠接受了一项反应时间任务的训练，在每次试验中，他们接受了一个，两个或三个药丸。预先随机确定每次试验的小球数量，并通过提示灯向大鼠发出信号。随着预期奖励的大小增加，大鼠的反应时间更快。鹅膏蕈氨酸损伤后，反应时间的模式或速度没有差异。虽然丘脑核的损伤并没有切断动机系统与运动系统的联系，但丘脑核可能参与了对外部刺激的激励显著性的学习。因此，术后测试后，提示意外事件被逆转。最初，这些线索继续根据它们先前的意义进行解释，但最终，受损大鼠和对照组都获得了新的关系，并且在相同的时间内完成。我们的结论是，在收购或表达的过程中，不同价值的奖励的期望被翻译成一个电机启动信号的丘脑核不参与。
The role of the nucleus accumbens in incentive motivation is accepted but poorly understood. In this study, we examined in the rat one aspect of motivated behaviour which might be mediated by the nucleus accumbens, namely the translation of a motivational signal (the expected value of a reward) into motor output (responding for the reward). Rats were trained in a reaction time task in which on each trial they received one, two or three pellets. The number of pellets for each trial was randomly determined in advance and signalled to the rats by cue lights, Rats responded with faster reaction times as the size of the expected reward increased. Following ibotenic acid lesions of the nucleus accumbens, there was no difference in the pattern or the speed of reaction times. Although lesions of the nucleus accumbens did not disconnect the motivational system from the motor system, it is possible that the nucleus accumbens is involved in the learning of the incentive salience of external stimuli. Therefore, after postoperative testing the cue contingencies were reversed. initially, the cues continued to be interpreted according to their prior significance, but eventually both the lesioned rats and the control group acquired the new relationship and did so in equivalent times. We conclude that the nucleus accumbens is not involved in the acquisition or expression of the processes whereby the expectation of rewards of different value is translated into a motor initiation signal.