Le Houezec J, Benowitz N L
Department of Medicine, San Francisco General Hospital Medical Center, University of California.
Clin Chest Med. 1991 Dec;12(4):681-99.
Nicotine acts on nearly every physiological system of the human body. While the actions of nicotine on the autonomic nervous system may be of interest in understanding possible deleterious long-term effects of smoking on the cardiovascular system, the actions of nicotine on the central nervous system are of the most interest in understanding why people smoke. Many studies of the effects of nicotine on human cognitive function have been performed. Improvement in attention, learning, reaction time, and problem solving have been reported. However, most of the results are inconclusive owing to methodologic problems. Whether the enhanced performance observed after smoking is attributable to relief of symptoms of abstinence or to a primary effect of nicotine on the brain is not clear. The pharmacodynamic effects of nicotine must be considered in the design of studies of the effects of nicotine on human performance. It is not known if the effects of nicotine on performance are subject to tolerance. The facilitation of performance, perceived as a reinforcement, may tend to lessen throughout the day, as do other effects of nicotine. Studies of chronic tolerance to the behavioral effects of nicotine are needed; comparisons between regular smokers and occasional smokers may be helpful. At present, the facilitatory actions of nicotine on human performance have been explained in terms of arousal. However, nicotine actions cannot be explained in terms of this single concept. Different processes, including attention, stimulus evaluation, and response selection, appear to be involved in the effect of nicotine on human information processing. Finally, one must consider that the predominant effects of nicotine may differ among individuals, as different people smoke for different reasons, and the motives for (rewards of) smoking may vary in different situations.
尼古丁作用于人体几乎每一个生理系统。虽然尼古丁对自主神经系统的作用可能有助于理解吸烟对心血管系统可能产生的有害长期影响，但尼古丁对中枢神经系统的作用对于理解人们吸烟的原因最为重要。已经进行了许多关于尼古丁对人类认知功能影响的研究。有报告称注意力、学习能力、反应时间和解决问题的能力有所改善。然而，由于方法学问题，大多数结果尚无定论。吸烟后观察到的表现增强是归因于戒烟症状的缓解还是尼古丁对大脑的直接作用尚不清楚。在设计尼古丁对人类表现影响的研究时，必须考虑尼古丁的药效学作用。目前尚不清楚尼古丁对表现的影响是否会产生耐受性。被视为一种强化的表现促进作用可能会像尼古丁的其他作用一样在一天中逐渐减弱。需要对尼古丁行为效应的慢性耐受性进行研究；比较经常吸烟者和偶尔吸烟者可能会有所帮助。目前，尼古丁对人类表现的促进作用已根据唤醒作用来解释。然而，尼古丁的作用不能仅用这一单一概念来解释。不同过程，包括注意力、刺激评估和反应选择，似乎都参与了尼古丁对人类信息处理的影响。最后，必须考虑到尼古丁的主要作用在个体之间可能存在差异，因为不同的人吸烟原因不同，而且吸烟的动机（回报）在不同情况下可能会有所不同。
