Methylphenidate and nicotine focus responding to an informative discrete CS over successive sessions of appetitive conditioning
Methylphenidate and nicotine focus responding to an informative discrete CS over successive sessions of appetitive conditioning
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DOI：
10.1177/0269881107083842
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发表时间：
2008-11-01
影响因子：
4.1
通讯作者：
Horsley, R. R.
中科院分区：
文献类型：
--
作者：
Cassaday, H. J.;Finger, B. C.;Horsley, R. R.
哌醋甲酯（MP）和尼古丁有望改善联想学习，尽管先前的证据表明它们应该降低形成联想的选择性。在这里，我们测试了它们对学习的影响之间的关联条件刺激（CS）和食物（无条件刺激，UCS）在雄性Wistar大鼠。在CS偏移后或10 s跟踪后立即（0 s）输送UCS。除了离散CS条件反射的措施，上下文和跟踪响应分别在试验间和刺激间的时间间隔进行测量。在所有情况下，条件反射都是通过用鼻子戳食物来测量的。MP和尼古丁都改善了离散线索条件反射的获得。在5 mg/kg但不是1 mg/kg MP和0.6 mg/kg但不是0.4 mg/kg尼古丁下，采集加速（与生理盐水相比）。在每种情况下，在0s但不是10s条件组中观察到这种效果。为了进行比较，以同样的方式重新分析了一些早先发表的数据，这些数据是按照与D-安非他明相同的程序获得的。安非他明同样改善了0s组的条件反射，在这种情况下，0.5，但不是1.5 mg/kg。因此，三种不同的多巴胺受体激动剂增加的能力，重点回应CS介绍了连续会议的食欲收购。
Methylphenidate (MP) and nicotine would be expected to improve associative learning, though previous evidence suggests that they should reduce the selectivity with which associations are formed. Here we tested their effects on learning the association between a conditioned stimulus (CS) and food (unconditioned stimulus, UCS) in male Wistar rats. The UCS was delivered immediately (0s) following CS offset or after a 10s trace. In addition to the measures of discrete CS conditioning, contextual and trace responding was measured in the inter-trial- and the inter-stimulus-interval, respectively. In all cases, conditioning was measured as nose poking for food. Both MP and nicotine improved the acquisition of discrete cue conditioning. Acquisition was accelerated (compared to saline) under 5 but not 1 mg/kg MP and 0.6, but not 0.4 mg/kg nicotine. In each case, this effect was observed in 0s but not 10s conditioned groups. For comparison, some earlier published data obtained following the same procedure with D-amphetamine were re-analysed in the same way. Amphetamine similarly improved conditioning in the 0s group, in this case at 0.5, but not 1.5 mg/kg. Thus three different dopamine agonists increased the ability to focus responding to CS presentations over successive sessions of appetitive acquisition.