Stolerman I P, Mirza N R, Hahn B, Shoaib M
Section of Behavioural Pharmacology, Institute of Psychiatry, De Crespigny Park, London, UK.
Eur J Pharmacol. 2000 Mar 30;393(1-3):147-54. doi: 10.1016/s0014-2999(99)00886-9.
Studies in smokers have suggested that at least part of the improved psychomotor performance produced by nicotine is the result of an effect on attention. Many animal experiments have assessed the effects of nicotine and its antagonists on diverse types of learning and memory but relatively few have looked at it in tasks designed to assess attention. In a five-choice serial reaction time task (5-CSRTT), rats with restricted access to food were presented with an array of five holes; illumination of a randomly selected hole signalled that a nose-poke into it would be reinforced by food presentation. Initially, signal length and the inter-trial interval (ITI) were varied and the procedure was demonstrated to satisfy some criteria for a vigilance task. The effects of nicotine on deficits in performance induced by varying signal length and ITI were assessed. Under appropriate conditions, small doses of nicotine increased the percentage of correct responses (accuracy), decreased omission errors and reaction time, and increased anticipatory responses. Subsequently, the effects of varying the ITI were examined more extensively in a slightly modified task. Here, nicotine produced small but robust, highly significant dose-related increases in accuracy, as well as decreases in omission errors and reaction times. Nicotine also increased accuracy when light stimuli were presented in an unpredictable manner. The nicotine antagonist mecamylamine produced a modest deficit in reaction time only. It is concluded that appropriate doses of nicotine can produce robust improvements in performance of normal rats in an attentional task. The effect cannot be attributed easily to changes in sensory or motor capability, learning or memory and may provide the measures needed to investigate the neuropharmacological and neuroanatomical bases of the elusive attentional effect of nicotine.
针对吸烟者的研究表明，尼古丁所带来的心理运动表现改善，至少部分是对注意力产生影响的结果。许多动物实验评估了尼古丁及其拮抗剂对多种学习和记忆类型的影响，但相对较少有实验在旨在评估注意力的任务中进行研究。在一个五选择连续反应时任务（5-CSRTT）中，给食物获取受限的大鼠呈现一排五个洞；随机选择的一个洞被照亮，表明向该洞探鼻会得到食物奖励。最初，改变信号长度和试验间隔时间（ITI），并证明该程序符合警觉任务的一些标准。评估了尼古丁对因信号长度和ITI变化而导致的行为表现缺陷的影响。在适当条件下，小剂量尼古丁增加了正确反应的百分比（准确性），减少了遗漏错误和反应时间，并增加了预期反应。随后，在一个稍作修改的任务中更广泛地研究了改变ITI的影响。在此，尼古丁使准确性有小但显著、与剂量高度相关的增加，同时减少了遗漏错误和反应时间。当以不可预测的方式呈现光刺激时，尼古丁也提高了准确性。尼古丁拮抗剂美加明仅使反应时间略有减少。得出的结论是，适当剂量的尼古丁可使正常大鼠在注意力任务中的表现得到显著改善。这种效应不易归因于感觉或运动能力、学习或记忆的变化，可能为研究尼古丁难以捉摸的注意力效应的神经药理学和神经解剖学基础提供所需的方法。
