Stolerman Ian P, Naylor Christopher G, Mesdaghinia Azam, Morris Hannah V
Section of Behavioural Pharmacology, Institute of Psychiatry, King's College London, London, UK.
Behav Pharmacol. 2009 Dec;20(8):742-54. doi: 10.1097/FBP.0b013e328333b290.
There is evidence that nicotine-induced enhancements of cognition may persist for days or even weeks after the drug has been cleared, but the generality of this effect is not known. The objective was to determine the time course of nicotine's effects on performance of the five-choice serial reaction time task (5-CSRTT) when the drug is given acutely and chronically. In the 5-CSRTT, rats were trained to obtain food reinforcers by detecting light stimuli and then received daily postsession injections of nicotine (0.4 mg/kg) or saline. The dose-related effects of presession injections of various acutely administered doses of nicotine were then determined at three different times after injection, whereas controls received saline only (n=12). Finally, performance of all animals was tracked for 8 days after the end of all dosing with nicotine. Daily postsession administration of nicotine for 16 days had no effect on performance the next day. Acute presession administration of nicotine positively influenced several response indices, confirming previous results. Daily administration of nicotine over a total period of 50 days weakened the effect of nicotine on response accuracy, perhaps because of an elevation of the baseline, but had no effect on other measures of performance. The effects of presession nicotine were very clear in tests carried out at 10 or 25 min after injection, and were less consistent at 75 min. There were no persisting differences between the performance of rats as a function of previous histories of exposure to nicotine everyday for 50 days, either under baseline conditions or when task demands were increased. The data suggest that there are no effects of nicotine on attentional performance in the 5-CSRTT that persist after exposure to the drug has ended.
有证据表明，尼古丁引起的认知增强效应在药物清除后可能会持续数天甚至数周，但这种效应的普遍性尚不清楚。目的是确定急性和慢性给予尼古丁时，其对五选择连续反应时任务（5-CSRTT）表现的影响的时间进程。在5-CSRTT中，训练大鼠通过检测光刺激来获得食物强化物，然后在每天实验结束后注射尼古丁（0.4mg/kg）或生理盐水。然后在注射后三个不同时间确定各种急性给予剂量的尼古丁预实验注射的剂量相关效应，而对照组仅接受生理盐水（n = 12）。最后，在所有尼古丁给药结束后，对所有动物的表现进行8天的跟踪。每天实验结束后给予尼古丁16天对第二天的表现没有影响。急性预实验给予尼古丁对几个反应指标有积极影响，证实了先前的结果。在总共50天的时间里每天给予尼古丁会削弱尼古丁对反应准确性的影响，可能是因为基线升高，但对其他表现指标没有影响。预实验给予尼古丁的效应在注射后10或25分钟进行的测试中非常明显，而在75分钟时则不太一致。在基线条件下或任务要求增加时，根据之前50天每天接触尼古丁的历史，大鼠的表现之间没有持续的差异。数据表明，在接触尼古丁结束后，尼古丁对5-CSRTT中的注意力表现没有持续影响。
