Acute and chronic nicotine effects on behaviour and brain activation during intertemporal decision making
Acute and chronic nicotine effects on behaviour and brain activation during intertemporal decision making
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DOI：
10.1111/adb.12057
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发表时间：
2014-09-01
影响因子：
3.4
通讯作者：
Smolka, Michael N.
中科院分区：
文献类型：
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作者：
Kobiella, Andrea;Ripke, Stephan;Smolka, Michael N.
先前的研究表明，吸烟者比不吸烟者对延迟奖励的折扣率更高。我们进行这项研究是为了确定这些颞间选择的差异是否由于尼古丁的药理作用，并跟踪相关的大脑区域。33名不吸烟者和27名尼古丁依赖吸烟者在执行跨期选择任务时接受了功能性磁共振成像，该任务由40组货币奖励选项组成，这些选项随交付的延迟而变化。在尼古丁饱和状态下对吸烟者进行了调查。非吸烟者接受了两次调查，在双盲、随机交叉设计中接受尼古丁（2毫克）和安慰剂口香糖。吸烟者比不吸烟者表现出更大的时间折扣。这些行为差异反映在大脑对两种金钱/时间选择的反应中：在安慰剂下，吸烟者的顶叶和枕叶区域（如楔前叶）的激活程度低于不吸烟者。在不吸烟者身上，单剂量尼古丁对大脑活动也有类似的影响，但对行为没有影响。抽烟者与不抽烟者对金钱/时间对的奖赏程度加工不同：抽烟者的腹侧纹状体反应性降低。此外，尼古丁对非吸烟者的奖励量加工有急性影响：尼古丁增加了左海马、杏仁核和前岛的血氧水平依赖性反应和平均量的相关性。我们的结论是，吸烟者和非吸烟者之间的横断面差异，部分是由于尼古丁的急性药理作用。需要进行纵向研究，以调查吸毒前群体的特征以及吸烟对打折行为的影响及其神经相关性。
Previous studies demonstrated higher discount rates for delayed rewards in smokers than non-smokers. We performed this study to determine whether those differences in intertemporal choice are due to pharmacological effects of nicotine and to track related brain regions. Thirty-three non-smokers and 27 nicotine-dependent smokers underwent functional magnetic resonance imaging while performing an intertemporal choice task consisting of 40 sets of monetary reward options that varied by delay to delivery. Smokers were investigated in a state of nicotine satiation. Non-smokers were investigated twice, receiving nicotine (2 mg) and placebo gums in a double-blinded, randomized cross-over design. Smokers displayed steeper temporal discounting than non-smokers. Those behavioural differences were reflected in the brain response during the decision between two alternative money/time pairs: smokers showed less activation in parietal and occipital areas (e. g. precuneus) than non-smokers under placebo. A single dose of nicotine in non-smokers led to a similar effect on brain activation but did not impact behaviour. Processing of the reward magnitude of money/time pairs differed between smokers and non-smokers: smokers showed decreased reactivity of the ventral striatum. Moreover, there was an acute nicotine effect in non-smokers on processing of the reward magnitude: nicotine increased the correlation of blood oxygen level-dependent response and mean amount in the left hippocampus, amygdala and anterior insula. We conclude that cross-sectional differences between smokers and non-smokers are only, in part, due to the acute pharmacological effects of nicotine. Longitudinal studies are needed to investigate pre-drug group characteristics as well as consequences of smoking on discounting behaviour and its neural correlates.